Can Scientists Define Life ?

[marc.t...@wanadoo.fr]

I would like to challenge you with the following controversial
statement: we can nothing about the origin of life.
I think it is true, perhaps for the same reason as the creationists,
but I am sure that these won’t agree with the next statements!
When scientists consider life as a scientifically sound concept they
are in a very difficult position, actually an impossible one.
Everybody can argue them: how can you assert that you will find how
life began when nobody can define it?
Actually there is a seeming consensus among the specialists in the
search for the origin of life (chemists, geochemists, biochemists,
biologists, exo/astrobiologists, computer scientists, philosophers and
historians of science) that there is an “obvious need for a definition
of life”. In spite of this wish everybody can observe the amazingly
high number of definitions of life, leading to reflect that skepticism
is multiplied by the above number, leaving almost no chance for new
formulations which, however, continue to appear!
Wouldn’t be that any definition of life is subjective and arbitrary as
is the boundary between living and nonliving systems or the moment
when nonliving systems would have become living? It is true that the
statement that any such boundary or moment exists is not falsifiable:
no experiment can be considered to prove that it can be false.
Therefore, if the distinction between living and nonliving systems is
a matter of belief and not science, it is not only hopeless but
useless to try to define this indefinable state related to a
metaphysical question!
If the concept of life is metaphysical then, it is true to say that we
can know nothing about the origin of life, as it is true to say that
we can know nothing about the origin of the soul, about the origin of
God etc.
On the contrary I don’t think it is true that we can know nothing
about the origin of the primordial ancestor on Earth, i.e. the origin
of all the terrestrial systems stemming from Darwinian evolution: we
can know about the origin of Darwinian evolution!

[John S. Wilkins]

You are making a mistake here that is quite common: confusing studying a
thing with defining it. We can study things we do not know how to
define, and we can define things that are not (scientifically)
investigable, like unicorns and fairies.

It may turn out, and I think it will, that we can give a blow-by-blow
description of the kind of chemical process that led from non-organic
chemical reactions ("inorganic" and "organic" have special meanings in
chemistry) to organic ones, and that at no stage is there a discrete
step from "not-life" to "life". We may decide that the very term "life"
is a nonscientific term, but I bet people will continue to use it.

We do not have to be able to define "life", so long as we can point to
standard examples of life. I can point to my children and say "life is
like *them*" - this is called an "ostensive definition" (to ostend is to
point). The desire for a hard and fast definition is a hangover from the
days when people tried to do science by definition.

By the way, the poeple who seem to want a definition of life most
ardently are the exobiologists at NASA, who think, wrongly, that if they
can define the sorts of chemical reactions and dynamics that all and
only life can do, they can build a detector for their probes. I think
they are doing science by definition.
--
John S. Wilkins, Associate, Philosophy, University of Sydney
http://evolvingthoughts.net
But al be that he was a philosophre,
Yet hadde he but litel gold in cofre

[James Beck]

Another very good reply.

[Josh Miles]

On 2/10/2012 5:27 PM, marc.t...@wanadoo.fr wrote:
> I would like to challenge you with the following controversial
> statement: we can nothing about the origin of life.

That's not controversial. It's just stupid.

[Friar Broccoli]

.

> You are making a mistake here that is quite common: confusing studying a
> thing with defining it. We can study things we do not know how to
> define, and we can define things that are not (scientifically)
> investigable, like unicorns and fairies.

Is this an example of "category error"? Or does it belong in a (or
perhaps several) different philosophical "box(es)"?

>
> It may turn out, and I think it will, that we can give a blow-by-blow
> description of the kind of chemical process that led from non-organic
> chemical reactions ("inorganic" and "organic" have special meanings in
> chemistry) to organic ones, and that at no stage is there a discrete
> step from "not-life" to "life". We may decide that the very term "life"
> is a nonscientific term, but I bet people will continue to use it.
>
> We do not have to be able to define "life", so long as we can point to
> standard examples of life. I can point to my children and say "life is
> like *them*" - this is called an "ostensive definition" (to ostend is to
> point). The desire for a hard and fast definition is a hangover from the
> days when people tried to do science by definition.
>
> By the way, the poeple who seem to want a definition of life most
> ardently are the exobiologists at NASA, who think, wrongly, that if they
> can define the sorts of chemical reactions and dynamics that all and
> only life can do, they can build a detector for their probes. I think
> they are doing science by definition.


--

Friar Broccoli (Robert Keith Elias), Quebec Canada
I consider ALL arguments in support of my views

[Bill]

On Feb 11, 11:50 am, Friar Broccoli <elia...@gmail.com> wrote:
> On 2012-02-10 19:01, John S. Wilkins wrote:
>
>
>
>
>
>
>
>
>

> > <marc.tess...@wanadoo.fr>  wrote:

.   .

>
> > You are making a mistake here that is quite common: confusing studying a
> > thing with defining it. We can study things we do not know how to
> > define, and we can define things that are not (scientifically)
> > investigable, like unicorns and fairies.
>
> Is this an example of "category error"?  Or does it belong in a (or
> perhaps several) different philosophical "box(es)"?
>

You are making a mistake that is quite common here. We can refute
errors without categorizing them.

[J. J. Lodder]

<marc.t...@wanadoo.fr> wrote:

Of course they can. How many do you want?

Counter question:
Is it possible for you to understand
that science isn't about definitions?

Or that talking about science isn't science?

Jan

[Athel Cornish-Bowden]

Yes, and the last sentence is particularly good.


--
athel

[Steven L.]

"marc.t...@wanadoo.fr" <marc.t...@wanadoo.fr> wrote in message
news:a11c3a2c-aec8-4c02...@v2g2000vbx.googlegroups.com:

> Actually there is a seeming consensus among the specialists in the
> search for the origin of life (chemists, geochemists, biochemists,
> biologists, exo/astrobiologists, computer scientists, philosophers and
> historians of science) that there is an "obvious need for a definition
> of life". In spite of this wish everybody can observe the amazingly
> high number of definitions of life, leading to reflect that skepticism
> is multiplied by the above number, leaving almost no chance for new
> formulations which, however, continue to appear!
> Wouldn't be that any definition of life is subjective and arbitrary as
> is the boundary between living and nonliving systems or the moment
> when nonliving systems would have become living? It is true that the
> statement that any such boundary or moment exists is not falsifiable:
> no experiment can be considered to prove that it can be false.
> Therefore, if the distinction between living and nonliving systems is
> a matter of belief and not science, it is not only hopeless but
> useless to try to define this indefinable state related to a
> metaphysical question!
> If the concept of life is metaphysical then, it is true to say that we
> can know nothing about the origin of life, as it is true to say that
> we can know nothing about the origin of the soul, about the origin of
> God etc.

Is God (if He exists) a "life form"?

He is supposed to be some disembodied spirit. But science-fiction
writers have had a field day writing about hypothetical life forms that
exist as pure energy or something else can perform the usual functions
of life without biochemical bodies.

Nevertheless, right here on Earth, though we may argue about viruses and
prions, there is universal agreement that things like procaryotes are
life forms. A single cell is a life form even if a virus may not be.

And how the first cell got started is still a legitimate scientific
question.



-- Steven L.

[marc.t...@wanadoo.fr]

"We can study things we do not know how to define"

I would be grateful if you could give us examples of material,
physical (in one word 'real') things that scientists cannot define
scientifically but that they can study?

"We do not have to be able to define "life", so long as we can point
to standard examples of life. I can point to my children and say "life
is like *them"

Your example (your children) belong to the category of "animals".
Indeed animals are among the most sophisticated extant terrestrial
systems being the outcome of more than 4 billions years of Darwinian
evolution! Then it is easy to say that they are different from, let's
say, minerals. Nevertheless, among the extant terrestrial systems
stemming from Darwinian evolution, there are also virus and above all
prions, for which the status of 'living' systems is very much debated,
isn't it?
The other major issue with the concept of life, as you admitt it ("at
no stage is there a discrete step from "not-life" to "life"), is the
miraculous moment when nonliving systems would have become living.
Moreover I would appreciate your reply to my statement that the
hypothesis that any such boundary or moment exists is not falsifiable
because no experiment can be envisaged to prove it to be false.

"By the way, the people who seem to want a definition of life most

ardently are the exobiologists at NASA, who think, wrongly, that if
they can define the sorts of chemical reactions and dynamics that all
and only life can do, they can build a detector for their probes."

You don't give your reasons why exobiologists at NASA are wrong, do
you?
These scientists are not the only ones who seem to want a definition
of life: scientists who are working on the origin of life too!

[marc.t...@wanadoo.fr]

"A single cell is a life form even if a virus may not be"

I suppose that, by "a cell", you mean a complex vesicle with all the
genetic machinery?
But what about lipid vesicles without this complex genetic machinery
but nevertheless with the capacity to reproduce and to transmit some
of their caracteristics to their daughter vesicles: are they living?

[AGWFacts]

On Fri, 10 Feb 2012 15:27:13 -0800 (PST), marc.t...@wanadoo.fr
wrote:

> I would like to challenge you with the following controversial
> statement: we can nothing about the origin of life.

Is this (above) a campaign for Chez Watt?


--
"I am not ignorant simply because I choose to believe one
theory over another." -- Madison Murphy

[Bob Casanova]

On Sat, 11 Feb 2012 06:09:13 -0800 (PST), the following
appeared in talk.origins, posted by marc.t...@wanadoo.fr:

As others have pointed out, definitions are sometimes
tricky. Do you think that everything that exists has a fixed
and unique definition? If you do, you're mistaken. The lack
of a universally-recognized and fixed definition for "life"
is no real handicap for those investigating abiogenesis
since they're investigating natural processes, not
dictionaries.

And please learn to set up attributions; it makes the thread
much easier to follow. No, I don't know how to do this in a
post via GurgleGroups, but I'm sure there's a help file.
--

Bob C.

"Evidence confirming an observation is
evidence that the observation is wrong."
- McNameless

[marc.t...@wanadoo.fr]

On 11 fév, 18:53, Bob Casanova <nos...@buzz.off> wrote:
> On Sat, 11 Feb 2012 06:09:13 -0800 (PST), the following

> appeared in talk.origins, posted by marc.tess...@wanadoo.fr:

Ok, but usually definitions help, particularly in science. In
mathematics, for instance, definitions are a prerequisite.
Indeed I just ask the following question: Are lipid vesicles without
the complex genetic machinery but with the capacity to reproduce and
to transmit some of their characteristics to their daughter vesicles
'living' systems? The answer can be: "yes" or "no" or "I don't know".
Of course any arguments with the response would be welcome.

[Steven L.]

"marc.t...@wanadoo.fr" <marc.t...@wanadoo.fr> wrote in message

news:5c2f3b47-cb89-4267...@w4g2000vbc.googlegroups.com:

I've always liked Isaac Asimov's own definition of biochemical life:

"Life is that which can effect a temporary and local decrease in entropy
by means of *catalyzed* chemical reactions."
-- Isaac Asimov


IOW, when thinking about what a life form is, you need to put at least
as much emphasis on metabolism as on reproduction.

Now a self-sustaining network of biochemical reactions capable of
extracting energy from the environment gives you the metabolism. One of
the things a life form can do with metabolism is make a copy of
itself--reproduce.

Try reading some of Stuart Kauffman's stuff. He takes the
dynamical-metabolism problem seriously.



-- Steven L.

[John S. Wilkins]

<marc.t...@wanadoo.fr> wrote:

> "We can study things we do not know how to define"
> I would be grateful if you could give us examples of material,
> physical (in one word 'real') things that scientists cannot define
> scientifically but that they can study?

Life

Gene

Species

Region

Niche

Mountain

Ecosystem

Disease

Society

Cognition

Planet

Star

Galaxy

Cloud

Climate

...

>
> "We do not have to be able to define "life", so long as we can point
> to standard examples of life. I can point to my children and say "life
> is like *them"
> Your example (your children) belong to the category of "animals".
> Indeed animals are among the most sophisticated extant terrestrial
> systems being the outcome of more than 4 billions years of Darwinian
> evolution! Then it is easy to say that they are different from, let's
> say, minerals. Nevertheless, among the extant terrestrial systems
> stemming from Darwinian evolution, there are also virus and above all
> prions, for which the status of 'living' systems is very much debated,
> isn't it?

Animals are alive if anything is. So what?

> The other major issue with the concept of life, as you admitt it ("at
> no stage is there a discrete step from "not-life" to "life"), is the
> miraculous moment when nonliving systems would have become living.

Objection, your worship. Facts not admitted in evidence!

> Moreover I would appreciate your reply to my statement that the
> hypothesis that any such boundary or moment exists is not falsifiable
> because no experiment can be envisaged to prove it to be false.

That is, to be sure, the very definition of "not falsifiable". But it is
not required for there to be a fact of living systems. Look up
"black and white" fallacy, and "sorites".

>
> "By the way, the people who seem to want a definition of life most
> ardently are the exobiologists at NASA, who think, wrongly, that if
> they can define the sorts of chemical reactions and dynamics that all
> and only life can do, they can build a detector for their probes."
> You don't give your reasons why exobiologists at NASA are wrong, do
> you?
> These scientists are not the only ones who seem to want a definition
> of life: scientists who are working on the origin of life too!

Really? I had no idea:

http://www.springerlink.com/content/h475867185551688/

[Bill]

Are they living? Who cares? If we can describe them accurately and
understand how they work, who cares whether we decide to call them
living or almost living or pseudo living or not living? The question
as to whether a virus is a living thing is a question about language,
not about viruses.

[Burkhard]

On Feb 11, 1:51 pm, marc.tess...@wanadoo.fr wrote:
> "We can study things we do not know how to define"
> I would be grateful if you could give us examples of material,
> physical (in one word 'real') things that scientists cannot define
> scientifically but that they can study?
>

"illness" and "health" woudl be two obvious examples, and medicine is
doing fine without them.
"I know it when I see it" is often good enough o get off the ground

<snip>

[James Beck]

I see that you are a troublemaker. What a superb teacher and mentor
you must be.

[Arkalen]

And while science DOES often define things in very precise ways so that
people can understand each other when they study them, those definitions
are limited to a certain field or context; it's the only way to get that
kind of precision. Take for example the different definitions of
"species" that apply to different situations (and then there are the
situations where scientists avoid the word entirely)

--
Arkalen
Praise be to magic Woody-Allen zombie superhero telepathic vampire
quantum hovercraft Tim! Jesus.

[John S. Wilkins]

Bill <broger...@gmail.com> wrote:

> On Feb 11, 11:50 am, Friar Broccoli <elia...@gmail.com> wrote:
> > On 2012-02-10 19:01, John S. Wilkins wrote:

...

> > > You are making a mistake here that is quite common: confusing studying a
> > > thing with defining it. We can study things we do not know how to
> > > define, and we can define things that are not (scientifically)
> > > investigable, like unicorns and fairies.
> >
> > Is this an example of "category error"? Or does it belong in a (or
> > perhaps several) different philosophical "box(es)"?

There are indefinitely many ways to carve up errors in reasoning,
because an error is the absence of correctness, and you can divide
privative classes many ways.

Taxonomies of fallacies are in general unenlightening.

> >
>
> You are making a mistake that is quite common here. We can refute
> errors without categorizing them.

Unless you are making some kind of mistake in saying that :-)

[Arkalen]

I know someone who thinks hurricanes are life forms.

Look, the way your brain creates "meaning" is to associate a bunch of
concepts with each other more or less strongly, based on your experience
and observations. When you create a definition, what you do is try to
impose a line in the world that neatly separates that association of
concepts from other concepts. Problem is, there is no reason for that
line to actually exist in the world. You can either create your
definition, and train your brain into making its idea of "meaning" match
the definition perfectly, or you accept there is no perfect definition,
but many different definitions that will apply in different contexts
(depending on which concepts we're emphasizing at any given time), all
with fuzzy borders.

[marc.t...@wanadoo.fr]

On 12 fév, 01:21, j...@wilkins.id.au (John S. Wilkins) wrote:

> John S. Wilkins, Associate, Philosophy, University of Sydneyhttp://evolvingthoughts.net

> But al be that he was a philosophre,
> Yet hadde he but litel gold in cofre

I begin by what I am the most interested in your response: I would be
grateful if you could send me the pdf of your article entitled
"Selection without replicators: the origin of genes, and the
replicator/interactor distinction in etiobiology.": I would like to
read it and send you my comments if you like it.

Your examples of material, physical (in one word 'real') things that
scientists cannot define scientifically but that they can study:
- Life: for me it is a metaphysical concept;
- Species: as Arkalen is saying, there are "different definitions of
'species' that apply to different situations and then there are
situations where scientists avoid the word entirely";
- Region: I supposed you mean that we cannot define an absolute
boudary for a 'region' in general but we must for a specific region;
- Niche: aproximatively the same situation as for 'species''
- Mountain: I supposed you mean that we cannot define an absolute
distinction between these different categories as 'rise in the
ground', 'hill', 'mountain' etc. However, when scientists are dealing
with such a specific 'rise in the ground' they will specify its
altitud accurately;
- Ecosystem: it is true that such a concept is vague but when
scientists are dealing with it they must specify their definition for
the given situation they are studying;
- Disease: I am physician and I can assert that physicians must define
a particular disease when they study it (e.g. consensus documents such
as the consensus document of The Joint European Society of Cardiology/
American College of Cardiology Committee for the redefinition of
myocardial infarction);
- Society: the same as for 'Ecosystem';
- Cognition: the same as for 'Ecosystem';
- Planet: a clear definition exists!
- Star: the same as for 'planet'!
- Galaxy: the same as for 'planet'!
- Cloud: the same as for 'Ecosystem';
- Climate: the same as for 'Ecosystem'.
I am a little puzzled by your view of what science is: is it because
you are a philosopher? For me 'philopsophy' is between science and
metaphysics: why didn't you choose 'philosophy' in your examples?

Animals:
You do not want to see the point: the fact you are taking the example
of the most complex extant terrestrial systems which is the result of
more than 4 billion years of Darwinian evolution and that it is far
easier that to make a distinction with minerals than for prions, for
example!

"The miraculous moment when etc."
Sorry, but I do not understand your objection and what you are meaning
by "Facts not admitted in evidence!": can you specify it?

Fasifiability of the concept of life:
"Black-or-white fallacy is a false dilemma fallacy that unfairly
limits you to only two choices" (Internet Encyclopedia of
Philosophy).
The distinction between nonliving and living systems is not a false
dilemma fallacy: it is necessary if you want to know something about
the origin of life.
As, for me, it is not possible to make such a distinction this is the
reason why I suggest to work on the origin of Darwinian evolution
instead, as you seem to do in your article entitled "Selection without
replicators: the origin of genes, and the replicator/interactor
distinction in etiobiology" but I would like to read it before, to be
sure, because the abstract is not so clear.

"Really? I had no idea"

Don't be too condescending: I am doing research in this domain too
(see http://en.wikipedia.org/wiki/Abiogenesis - the paragraphs "Lipid
world" and "Origin of Darwinian evolution rather than origin of
life")

[marc.t...@wanadoo.fr]

Of course, as a physician, I totally disagree with you: see my
response to John S. Wilkins about the word 'disease'.

[Burkhard]

Your answer was that you can define a specific disease. That is the
same thing that John did before for specific living things, so you are
really proving his point.

[marc.t...@wanadoo.fr]

I totally agree with you!

[marc.t...@wanadoo.fr]

I see your point. You are right that the word 'disease' in general has
no clear and universal definition, such as "good health'. In France,
for example, it is an important point because French have what is
called "Sécurité Sociale" which is free for everybody. Then, indeed,
only specific diseases (with definitions as precise as possible) are
taken care of by the "Sécurité Sociale"!
There is the same kind of problem with the distinction between
'normality' and abnormality'. However, when dealing with a practical
issue you must define as exactly as possible, what you intend by
abnomelity: e.g. abnormal values for glycaemia.

In the case of the word' life' there is no problem for people to use
it in the ordinary life (!). But if scientists want to know about the
origin of life I don't see how they can if they can't make a clear
distinction between living and nonliving systems.
By contrast I think it is possible to make such a clear distinction
between systems with the possiblity to evolve by natural selection
(e.g. lipid vesicles without this complex genetic machinery but with
the capacity to reproduce and transmit some of their caracteristics to
their daughter vesicles) and systems without this possiblity (e.g.
current experimental lipid vesicles).

[Arkalen]

(2012/02/12 19:59), marc.t...@wanadoo.fr wrote:

> I totally agree with you!
>

The question "Who cares?" is usually a rhetorical question meant to say
that nobody SHOULD care. It is pretty obviously the case here. Yet you
care about the question quite a lot, and you think scientists should
care about the question too. So what is it you're agreeing with here ?

[Arkalen]

What does "metaphysical" mean ?

> - Species: as Arkalen is saying, there are "different definitions of
> 'species' that apply to different situations and then there are
> situations where scientists avoid the word entirely";

... And the same is true of life ! If you're satisfied with my response
about species, why are you looking for an absolute all-encompassing
definition of "life" ?

> - Region: I supposed you mean that we cannot define an absolute
> boudary for a 'region' in general but we must for a specific region;
> - Niche: aproximatively the same situation as for 'species''
> - Mountain: I supposed you mean that we cannot define an absolute
> distinction between these different categories as 'rise in the
> ground', 'hill', 'mountain' etc. However, when scientists are dealing
> with such a specific 'rise in the ground' they will specify its
> altitud accurately;

And when scientists are dealing with a system they can specify to what
extent it reproduces, metabolizes, dissipates energy, locally reduces
entropy, consists of catalyzed chemical reactions, behaves
teleologically, etc etc.

> - Ecosystem: it is true that such a concept is vague but when
> scientists are dealing with it they must specify their definition for
> the given situation they are studying;
> - Disease: I am physician and I can assert that physicians must define
> a particular disease when they study it (e.g. consensus documents such
> as the consensus document of The Joint European Society of Cardiology/
> American College of Cardiology Committee for the redefinition of
> myocardial infarction);
> - Society: the same as for 'Ecosystem';
> - Cognition: the same as for 'Ecosystem';
> - Planet: a clear definition exists!

Which is somewhat arbitrary ! As is the definition of "mountain"
(something higher than 1000m above sea level IIRC), and tons of those
limited definitions scientists work with.

> - Star: the same as for 'planet'!
> - Galaxy: the same as for 'planet'!
> - Cloud: the same as for 'Ecosystem';
> - Climate: the same as for 'Ecosystem'.
> I am a little puzzled by your view of what science is: is it because
> you are a philosopher? For me 'philopsophy' is between science and
> metaphysics: why didn't you choose 'philosophy' in your examples?
>
> Animals:
> You do not want to see the point: the fact you are taking the example
> of the most complex extant terrestrial systems which is the result of
> more than 4 billion years of Darwinian evolution and that it is far
> easier that to make a distinction with minerals than for prions, for
> example!

That IS the point. "life" as we think of it has a collection of
attributes. Some things undisputably have all those attributes and we
have no problem calling them "alive"; moreover enough of these things
have all those attributes, and enough things have none of them, that
they form a cluster and it is a perfectly useful term.

Thing is, none of those attributes are absolutely dependent on one
another, so we get lots of "fuzzy" cases where something will have some
attributes of life and not others (whether in the real world, or in
potentia and mostly the realm of science-fiction writers, but who knows
what's out there. And what we might come up with in the future).

There is simply no unambiguous set of characters we can imagine that
will result in everything we naively think of as "life" being covered
and everything we naively think of as "non-life" being excluded. That's
because our naive concepts of the word are formed by our everyday
experiences, which don't include things like the detailed lifecycle of
the virus or prion or intelligent androids.

By the way, it isn't the 4 billion years of evolution that make
"animals" the easiest thing to define as "alive". It's that "animals"
(and even more : "large tetrapods") are our brains' template for what
"alive" IS. It's why people will sometimes attribute intentionality to
things that move and call them "alive", but will forget that plants are
alive too.

>
> "The miraculous moment when etc."
> Sorry, but I do not understand your objection and what you are meaning
> by "Facts not admitted in evidence!": can you specify it?
>
> Fasifiability of the concept of life:
> "Black-or-white fallacy is a false dilemma fallacy that unfairly
> limits you to only two choices" (Internet Encyclopedia of
> Philosophy).
> The distinction between nonliving and living systems is not a false
> dilemma fallacy: it is necessary if you want to know something about
> the origin of life.

Not so. As with the mountain example, people can look at what attributes
a borderline system has and see which attributes usually found in living
things it has, and which attributes it has that aren't in living things,
and thus characterize it fully and study it AS a possible step in the
formation of life, without having to decree which side of the
living/nonliving boundary it falls in.

> As, for me, it is not possible to make such a distinction this is the
> reason why I suggest to work on the origin of Darwinian evolution
> instead, as you seem to do in your article entitled "Selection without
> replicators: the origin of genes, and the replicator/interactor
> distinction in etiobiology" but I would like to read it before, to be
> sure, because the abstract is not so clear.
>
> "Really? I had no idea"
> Don't be too condescending: I am doing research in this domain too
> (see http://en.wikipedia.org/wiki/Abiogenesis - the paragraphs "Lipid
> world" and "Origin of Darwinian evolution rather than origin of
> life")
>

[Burkhard]

Isn't the opposite the case? If it were _always_ straightforward to
distinguish living from non-living things, explaining how one gave
rise to the other would be problematic - our definitions have created
a (semantic) chasm. Instead, what we have are things that clearly are
alive (you, trees, lions, bacteria) and things that aren't (rocks,
houses, the late Conan Doyle). To get from one to the other, we should
expect to find a substantial grey area where the call is more and more
difficult to make.

Same with origin of languages. There is no precise definition of "old
French" or "modern French". But we do ave diagnostic criteria (e.g.
the /wo/ -> /we/ shift for old French, the loss of "ne" in
negotiations (I got penalised in school, but my pen friends thought I
was writing in a funny "old fashioned" style) They are not
definitions, as they can occur on both sides of a hypothesized
boundary) but if you have several together, you can classify a text.
Then we have clear examples for both, such as the Girart de Vienne for
Old French or Didier Daeninckx for modern French. That is more than
enough to develop theories about their respective origins - (and of
course lots of problematic "border crossers" whose precise pace can be
debated no end - are the Serments de Strasbourg an example of
"speciation" that shows how the empire was breaking up and new
languages formed, or did it simply reflect much older divisions?

[Arkalen]

My guy who thought "life" should include hurricanes pointed out that
whirlpools like that will spawn other whirlpools, which share
characteristics with their parent whirlpool. Are hurricanes subject to
Darwinian evolution ? Are they a meaningful model for the origin of life ?

Someone brought up stars as an example of things that "reproduce" in the
conversation about nested hierarchies earlier, pointing out that younger
stars are formed from the supernovae of older stars. Presumably the
younger stars share *some* characteristics with their parents, seeing as
they're made from a lot of the same stuff.

"Is subject to Darwinian evolution" itself has fuzzy borders. Again, our
everyday evolved life-forms are clear unambiguous cases, with a very
high fidelity of replication (but not quite 100%, leaving space for
variation), a very stable structure and environment that means we have
an unbroken line of descent going back billions of years, so on.

Something that has a replication fidelity of 0, or is so unstable it
only persists for a generation, isn't subject to Darwinian evolution;
indeed it doesn't reproduce at all.

But in between 0% fidelity and 99%, and 1 generation and 1 trillion...
you can get fuzziness.

[Ernest Major]

In message
<5d18fa0a-fe2e-4582...@g27g2000yqa.googlegroups.com>,
marc.t...@wanadoo.fr writes

>- Planet: a clear definition exists!

Recently the astronomical community concluded that it was inappropriate
to classify Pluto as a planet on the grounds that it was merely the
largest (or not even that) of a collection of bodies (kuiperoids,
plutinos) sharing several characteristics.

In doing so, they defined "clearing its orbit" as a criterion which must
be met by a planet. Unfortunately "clearing its orbit" is not an
unambiguous term, so we don't actually have a clear definition.

Furthermore, that definition is a dynamical definition - it depends on
orbits, rather than the nature of the body - and many people, myself
included, would prefer that planets be defined by intrinsic properties,
such as mass and composition. (I'd argue for 15 planets in the Solar
System.) The definition excludes "rogue planets", that is planets that
do not orbit any star. And there are other edge cases, such as a
Mars-sized object in a Trojan point of a brown dwarf, or the smaller (or
both) members of a double planet, or two bodies that periodically swap
orbits (as do two of Saturn's shepherd moons).

>- Star: the same as for 'planet'!

When does a protostar become a star? Is a black hole a star? Is a white
dwarf a star? Is a black dwarf a star? Is a brown dwarf a star? Is a
neutron star a star?

>- Galaxy: the same as for 'planet'!

As the Milky Way tears apart and cannibalises the Magellanic Clouds,
when do they stop being galaxies and become part of the Milky Way? Where
is the dividing line between an intergalactic globular cluster and a
dwarf galaxy? Is a galactic mass gas cloud a galaxy before it forms
stars?
--
alias Ernest Major

[marc.t...@wanadoo.fr]

On 12 fév, 14:20, Arkalen <arka...@inbox.com> wrote:

> > (seehttp://en.wikipedia.org/wiki/Abiogenesis-  the paragraphs "Lipid

> > world" and "Origin of Darwinian evolution rather than origin of
> > life")
>
> --
> Arkalen
> Praise be to magic Woody-Allen zombie superhero telepathic vampire
> quantum hovercraft Tim! Jesus.

"What does 'metaphysical' mean?"
For me the best synonym is "transcendental": i.e. which supposes the
intervention of a superior principle beyond the real world.

"And the same is true of life ! If you're satisfied with my response
about species, why are you looking for an absolute all-encompassing
definition of 'life'?"

I agree when you say: "then there are situations where scientists
avoid the word ENTIRELY", particularly in the situation where
scientists want to know about the origin of all extant and past
terrestrial systems stemming from Darwinian evolution.

"it reproduces, metabolizes, dissipates energy, locally reduces
entropy, consists of catalyzed chemical reactions, behaves
teleologically"

And what else? We do not need so much to make Darwinian evolution
working (although your description is not too far from a collection of
systems with possible natural selection and Darwinian evolution).
Within my approach it is possible to envisage less restrictive systems
and thus more likely ones, although more original.

What do think of the MAGIC moment when nonliving systems would have
become living?

[marc.t...@wanadoo.fr]

On 12 fév, 14:37, Arkalen <arka...@inbox.com> wrote:

Hurricanes are thermodynamically far-from-equilibrium systems but I
have never heard that they can reproduce: can you provide some good
scientific references about it?

"stars are formed from the supernovae of older stars"

More precisely new stars are formed from huge clouds of hydrogen
present in galaxies: when a big star of a galaxy reaches the end of
its 'live' (no more nuclear fuel) it explodes (= supernova) and the
explosion, if the cloud is not too close, targets the formation of a
star from the gravitational collapse of the cloud.

[marc.t...@wanadoo.fr]

On 12 fév, 14:22, Arkalen <arka...@inbox.com> wrote:

I agree with Bill when he says: "The question as to whether a virus is

a living thing is a question about language, not about viruses".

I would like just to add that, on the contrary, the fact that a
collection of viruses can evolve says something very important on
viruses.

[Arkalen]

So you're some kind of vitalist ? By which I mean, you believe there's
some kind of "living force" that uniquely distinguishes the living from
the non-living ?

AFAICT the definition of life is something that would apply to life as
it is, not just to how it started. So the definition of life being
metaphysical would imply you think life itself, as it currently is, is
metaphysical. I guess things CAN be defined by their origin instead of
their characteristics but I'm not sure how it would work here.

Either way, if you think there is a very clear difference between life
and non-life, in that life supposes the intervention of a superior
principle beyond the real world to an extent non-life doesn't, then we
should EXPECT life to be easily definable. How do you account for the
fact it isn't ?

(also, and this may or may not be semantics, did you really mean to say
"beyond the real world" ? Are you saying life is caused by something
that isn't real ?)

>
> "And the same is true of life ! If you're satisfied with my response
> about species, why are you looking for an absolute all-encompassing
> definition of 'life'?"
> I agree when you say: "then there are situations where scientists
> avoid the word ENTIRELY", particularly in the situation where
> scientists want to know about the origin of all extant and past
> terrestrial systems stemming from Darwinian evolution.

But you seem to think they SHOULDN'T avoid the word, and that they
should instead define it as a prerequisite to studying that origin. If
that isn't what you think, what are we talking about here ?

>
> "it reproduces, metabolizes, dissipates energy, locally reduces
> entropy, consists of catalyzed chemical reactions, behaves
> teleologically"
> And what else? We do not need so much to make Darwinian evolution
> working (although your description is not too far from a collection of
> systems with possible natural selection and Darwinian evolution).
> Within my approach it is possible to envisage less restrictive systems
> and thus more likely ones, although more original.

See my response elsethread on why "systems that make Darwinian evolution
work" is no more well-defined than "life" is.

And you do not seem at all to address my point that people can describe
and fully characterize systems that are in the fuzzy boundary between
life and non-life without having to decree which side of the line they
fall on, and that this is enough to be able to study them.

>
> What do think of the MAGIC moment when nonliving systems would have
> become living?
>

Same thing I think of the MAGIC moment when prehistoric non-human apes
became human, or the MAGIC moment when a child becomes an adult. It's
not magic (except figuratively), and it's not a moment.

How do you account for the difficulty in distinguishing life from
non-life, if the transition happened so sharply ? Not to mention MAGICALLY.

[Arkalen]

No; it wasn't my idea, and I really don't have time to look it up. (I
just remembered though; the word I was looking for wasn't "whirlpool",
it's "eddy")

You can probably find something in resources on fluid dynamics or something.

>
> "stars are formed from the supernovae of older stars"
> More precisely new stars are formed from huge clouds of hydrogen
> present in galaxies: when a big star of a galaxy reaches the end of
> its 'live' (no more nuclear fuel) it explodes (= supernova) and the
> explosion, if the cloud is not too close, targets the formation of a
> star from the gravitational collapse of the cloud.
>

Yeah, but I wasn't talking about the details of star formation, I was
talking about how whether a system is subject to Darwinian evolution or
not becomes fuzzy in systems with low-fidelity reproduction or who don't
persist (or simply haven't had time to persist...) for many generations.
How about that ? We can point to the various sets of parameters under
which genetic algorithms work or don't work if you don't like my
real-life examples.

Associated question prompted by your response to my other post in this
thread : in what way does looking at Darwinian evolution instead of
"life" have anything to do with the magic moment life began ? I mean, if
we can unambiguously define systems that are subject to Darwinian
evolution, and you yourself can think of very very simple systems that
are subject to it, what makes the "moment Darwinian evolution started"
magical ?

[marc.t...@wanadoo.fr]

On 12 fév, 15:11, Ernest Major <{$t...@meden.demon.co.uk> wrote:
> In message
> <5d18fa0a-fe2e-4582-a43f-0c28698d6...@g27g2000yqa.googlegroups.com>,
> marc.tess...@wanadoo.fr writes

I think the correct explanation is that Pluto was captured by the
solar system later after the formation of the latter: planets should
form at the same time as the star(s) around which they orbit.

"When does a protostar become a star? "

See my explanation to Arkalen.

"As the Milky Way tears apart and cannibalises the Magellanic Clouds,
when do they stop being galaxies and become part of the Milky Way?"

Presently these galaxies belong to the Milky Way's satellite system
which is part of the Local Group (from wikipedia: "Local Group").

[marc.t...@wanadoo.fr]

On 12 fév, 15:52, Arkalen <arka...@inbox.com> wrote:

> some kind of "living ...
>
> plus de détails »

My answer to your question about metaphysics means only that
metaphysics is different from science.

[Arkalen]

Sadly, that is meaningless unless you explain HOW it's different from
science.

Science is about understanding the real world. In a way your second
statement is completely consistent with the first in that you seem to
say life was started by something that wasn't real, but that's just a
confusing idea I'd like to see some elaboration on.

At any given time there are tons of things in the real world that
science can't investigate... But experience has shown that's mostly for
lack of tools. The creation of things like telescopes, microscopes,
statistical analysis, MRIs, surveys, computers and so on has brought
many domains that used to be the province of philosophy, religion and
literature more into the realm of science, and the process is ongoing.

Surely when you say "metaphysics is different from science" you don't
just mean metaphysics is different from science *right now*, but it's
intrinsically different from science and will always be.
So given the continual expansion of science's field of inquiry, how do
you know whether something is metaphysical or not ?

Oh, and I'm just remembering this started when you said life is a
metaphysical concept to you. Does this mean you don't think life is
something science can investigate ? And what does THAT mean ? I mean,
abiogenesis is a tough nut to crack but biologists have been figuring
how life works for over a century. Sounds like scientific investigation
to me. That's why I asked whether you were a vitalist, because that's
the most straightforward interpretation I see of life being "metaphysical".

Or maybe I'm completely misunderstanding what you mean by "metaphysical
concept" ?

[Ernest Major]

In message
<074825af-78de-45f0...@y10g2000vbn.googlegroups.com>,
marc.t...@wanadoo.fr writes

That is not a mainstream position on the origin of Pluto. The mainstream
position is that kuiperoids are bodies which were neither expelled from
the Solar System during its formation, nor incorporated into planets.

You might also like to investigate the observations of planets orbiting
pulsars, which would seem to form a counterexample to your proposed
criterion.

Regardless, your response is not a defence of your claim that planet has
an unambiguous definition.

>
>"When does a protostar become a star? "
>See my explanation to Arkalen.

That is an insufficiently precise reference.

>
>"As the Milky Way tears apart and cannibalises the Magellanic Clouds,
>when do they stop being galaxies and become part of the Milky Way?"
>Presently these galaxies belong to the Milky Way's satellite system
>which is part of the Local Group (from wikipedia: "Local Group").
>

That is not a defence of your claim that galaxy has an unambiguous
definition.
--
alias Ernest Major

[Athel Cornish-Bowden]

I'm not sure I understand your point here. Maybe you took my comment as
being sarcastic, but it wasn't intended to be. Actually I now realize
that the sentence i liked ("I think they are doing science by
definition") is ambiguous in a way that I hadn't previously noticed. I
took it as echoing a previous sentence ("The desire for a hard and fast

definition is a hangover from the days when people tried to do science

by definition") that was clearly not intended to treat "science by
definition" as something good. I still think that is probably what John
Wilkins meant, but the sentence could be read to mean that by the
definition of science what these people are doing is science. If that
is what he meant then I don't agree.


--
athel

[marc.t...@wanadoo.fr]

> >>>>> (seehttp://en.wikipedia.org/wiki/Abiogenesis-the paragraphs "Lipid

I understand your perplexity. I'll try to explain my point of view
more clearly.
When I state that the concept of life is 'metaphysical' I mean that it
is a concept that science (i.e. scientists) cannot investigate. This
is because the physical existence of the distinction between living
systems and nonliving ones is not falsifiable: nobody can imagine an
experiment to prove it to be false (Popper's condition for a
scientific assertion).
On the contrary I think that several experiments can be performed to
test the hypothesis that it is the origin of Darwinian evolution which
is interesting to investigate (and actually I imagine such experiments
in a recent publication which is accessible via Wikipedia by the
following link: http://en.wikipedia.org/wiki/Abiogenesis, reference n
°130).

[marc.t...@wanadoo.fr]

That is one of the main difference with 'life': we can imagine a
moment when Darwinian evolution started which is NO MAGIC AT ALL:
within the model I propose the major difference between the current
experimental lipid vesicles (which cannot evolve) and the ones which
would be able to suffer natural selection and evolve is the
heritability of specific characteristics of the latter (cf. reference n
°130).

[Arkalen]

I'm afraid I don't understand that sentence at all. Not that Popper is
the be-all, end-all of science anyway, but what does it mean for a
"distinction between living systems and nonliving ones" to be proven
false ? Does that mean picking a characteristic difference between
living and nonliving systems, and proving that it does indeed match our
naive concepts of living vs nonliving systems ? But that can absolutely
be proven false, like when people thought that organic molecules were
characteristic of living systems (this was proven false with the
synthesis of urea). Or when people pick some unique defining
characteristic for life and it can be shown to be unsatisfactory on its
own (like defining life by "can reproduce", which excludes organisms
that happen to be sterile for example).

Also, you are still not addressing what most people have been telling
you, which is that a clear distinction between living and nonliving is
NOT NECESSARY for the study of the origin of life. Systems can be
characterized, both from their components and from their possible
similarities to some step in the origin of life, without needing to slap
a "living" or "nonliving" label on them.

> On the contrary I think that several experiments can be performed to
> test the hypothesis that it is the origin of Darwinian evolution which
> is interesting to investigate (and actually I imagine such experiments
> in a recent publication which is accessible via Wikipedia by the
> following link: http://en.wikipedia.org/wiki/Abiogenesis, reference n
> °130).
>

And that is even stranger. "The hypothesis that it is the origin of
Darwinian evolution which is interesting to investigate" ? That sounds
like those mathematical proofs that all natural numbers are interesting
("0 is interesting. Now consider the lowest non-interesting number. Hey,
it's the lowest non-interesting number, that's pretty interesting ! QED").

Whether something is "interesting" or not is a personal judgment call,
which can be backed with various good or bad reasons that would convince
others to be interested too, but it isn't *a scientific hypothesis* for
Heaven's sake. I don't see what falsifiability has to do with it.

I'm sure you meant something different but I can't tell what, or what
metaphysics has to do with Darwinian evolution.

Also, from the abstract of your paper : "If we replace the search for
the origin of life by the one for the origin of evolution our priority
first is to find a consensus on the minimal conditions that would allow
evolution to emerge and persist anywhere in the universe."

How much do you know about genetic algorithms ? Those follow the minimal
conditions for evolution (replication, random mutations, non-random
selection), but in order to actually reproduce life-like Darwinian
evolution you need a whole lot of parameters to be in the correct ranges.

[Arkalen]

Is that so now. You can imagine a non-magical moment when systems that
previously didn't replicate suddenly started replicating with, say, 80%
fidelity ?

Because you won't get Darwinian evolution from systems that replicate
with 1% fidelity, I can tell you that.

But then maybe the system just before Darwinian evolution started did
replicate, it was just with a fidelity that was a teeeeeeeeny bit too
low for Darwinian evolution to happen...

So at what percentage point did Darwinian evolution suddenly start ?

[Friar Broccoli]

On 2012-02-12 02:36, John S. Wilkins wrote:
> Bill<broger...@gmail.com> wrote:
>
>> On Feb 11, 11:50 am, Friar Broccoli<elia...@gmail.com> wrote:
>>> On 2012-02-10 19:01, John S. Wilkins wrote:
> ....

>>>> You are making a mistake here that is quite common: confusing studying a
>>>> thing with defining it. We can study things we do not know how to
>>>> define, and we can define things that are not (scientifically)
>>>> investigable, like unicorns and fairies.
>>>

>>> Is this an example of "category error"? Or does it belong in a (or
>>> perhaps several) different philosophical "box(es)"?
>
.

> There are indefinitely many ways to carve up errors in reasoning,
> because an error is the absence of correctness, and you can divide
> privative classes many ways.
>
> Taxonomies of fallacies are in general unenlightening.

Useful comment, which helps me understand why I have found the effort to
produce such a classification system so frustrating.

I had thought my problem was an absence of any understanding of the
basic rules of logic.


>>>
>>
>> You are making a mistake that is quite common here. We can refute
>> errors without categorizing them.
>
> Unless you are making some kind of mistake in saying that :-)


--
Friar Broccoli (Robert Keith Elias), Quebec Canada
I consider ALL arguments in support of my views

[marc.t...@wanadoo.fr]

On 12 fév, 18:49, Arkalen <arka...@inbox.com> wrote:

My statement that the physical existence of the distinction between
living systems and nonliving ones is not falsifiable and cannot be
tested is related to the fact that nobody can formulate an universal
definition of life. Thus, if somebody is doing a given experiment
based on HIS definition of life anybody, with a DIFFERENT definition
of life, can refute the relevance of his experiment ... and so on.
On the contrary, I think it is possible to find a consensus on the
minimum prerequisite for making Darwinian evolution working (I can
specify you my proposal). If my statement that such a consensus is
true then any experiment based on this prerequisite would be relevant
to prove that a given model is false or not.

"How much do you know about genetic algorithms ? Those follow the
minimal conditions for evolution (replication, random mutations, non-
random selection), but in order to actually reproduce life-like
Darwinian evolution you need a whole lot of parameters to be in the
correct ranges."

One the main consequences of my approach (i.e. to focus on the origin
of Darwinian evolution) is that the minimum prerequisite I propose
doesn't require the existence of nucleic acids (on which I think
genetic algorithms are based, aren't they?) nor the existence of amino-
acids. This is actually the case of the model of lipid vesicles with
an heterogeneous membrane I propose (you must read the full paper to
understand better what I mean).

[marc.t...@wanadoo.fr]

On 12 fév, 18:56, Arkalen <arka...@inbox.com> wrote:

I must specify that the ONLY difference between the two kinds of
vesicles is the heritability of specific characteristics: actually
these specific characteristics, which are not related to nucleic acids
or amino-acids, are transmitted to the daughter vesicles WITHOUT ANY
CHANGE: then 100% of the information is transmitted.
Indeed, within such a model, there are possibilities for a KIND of
mutations (which is not described in the article because I found it
later on): when such a mutation occurrs the change is weak but
significant in term of what can be called a phenotypic change, i.e. a
possible occurrence of a NEW property.

[Arkalen]

As far as I can tell those two statements are contradictory. If we can't
formulate a universal definition of life, then any one distinction we
draw between living systems and nonliving ones is false, i.e.
falsified... which means they have to be falsifiable.

> Thus, if somebody is doing a given experiment
> based on HIS definition of life anybody, with a DIFFERENT definition
> of life, can refute the relevance of his experiment ... and so on.

I don't see the logical link here at all. You might be talking about how
there are many different ways of distinguishing life from non-life, and
different ones are preferred by different people, in different contexts,
for different purposes. I don't see how that makes such distinctions
"unfalsifiable". It looks to me as if you're taking a word that applies
to scientific hypotheses, and applying it to the meta-questions of
whether a scientific hypothesis is relevant or interesting. I don't
think that works at all.

> On the contrary, I think it is possible to find a consensus on the
> minimum prerequisite for making Darwinian evolution working (I can
> specify you my proposal). If my statement that such a consensus is
> true then any experiment based on this prerequisite would be relevant
> to prove that a given model is false or not.

That's nice, but you haven't responded to any of my objections to there
being such a simple consensus, except for nitpicking a few examples
which I don't think affects my larger point much.

>
> "How much do you know about genetic algorithms ? Those follow the
> minimal conditions for evolution (replication, random mutations, non-
> random selection), but in order to actually reproduce life-like
> Darwinian evolution you need a whole lot of parameters to be in the
> correct ranges."
> One the main consequences of my approach (i.e. to focus on the origin
> of Darwinian evolution) is that the minimum prerequisite I propose
> doesn't require the existence of nucleic acids (on which I think
> genetic algorithms are based, aren't they?)

I don't think it's relevant. The "genes" in a genetic algorithm have
about as much resemblance to actual genes as the "neurons" in a neural
network have to actual neurons. As all things with computers it all has
to come down to series of ones and zeros at some point, but at the end
of the day they're entities that replicate imperfectly, which is what
your vesicles are right ?

[Arkalen]

In that case Darwinian evolution is impossible. I don't think perfect
replication is even possible especially as the number of generations
increases, there must be a thermodynamics thing at work there. But if it
were, perfect replicants would never evolve.

> Indeed, within such a model, there are possibilities for a KIND of
> mutations (which is not described in the article because I found it
> later on): when such a mutation occurrs the change is weak but
> significant in term of what can be called a phenotypic change, i.e. a
> possible occurrence of a NEW property.
>

So... there IS change.

And how do you go from non-replicating vesicles to near-perfectly
replicating vesicles ? I notice you said the ONLY difference between the
two kinds of vesicles (by which I assume you mean current experimental
vesicles, and your theoretical vesicles) is that the latter reproduce
with perfect heritability. But that... is not a small difference !
Nothing in the Universe replicates near-perfectly the way life does, and
life needs a buttload of complex machinery to achieve that. Do those
reproducing vesicles have specific characteristics that make them
reproduce the way their current experimental comrades don't ?

It reminds me a bit of when I was a kid and I wondered why we had blood
instead of just water that contained all the stuff necessary to serve
whatever purposes blood served. Is it possible that something that's
just like the current experimental vesicles, with only the differences
necessary to make it replicate... would be a proto-cell ?

[marc.t...@wanadoo.fr]

Actually If we can't formulate a universal definition of life that
doesn't mean that any distinction drawn between living systems and
nonliving ones is false: that means that it is impossible to just
imagine any one distinction between living systems and nonliving ones.
Then this the reason why it is not falsifiable.

"That's nice, but you haven't responded to any of my objections to
there being such a simple consensus, except for nitpicking a few
examples which I don't think affects my larger point much."

Sorry, but could you tell me again your objections?

"As all things with computers it all has to come down to series of
ones and zeros at some point, but at the end of the day they're
entities that replicate imperfectly, which is what your vesicles are
right?"

- First, my model has nothing to do with a computer approach.
- Second, the fact that the vesicles are able to reproduce is not a
specific property of my model as the current experimental vesicles are
able to reproduce too.
- Third, the specificity of my vesicles is that they are able to
transmit specific characteristics (related to specific phenotypic
properties) to their descendants.

[Arkalen]

I still don't see the logical link between those two sentences. Maybe it
would help if you explained what it means for a distinction to be "false" ?

>
> "That's nice, but you haven't responded to any of my objections to
> there being such a simple consensus, except for nitpicking a few
> examples which I don't think affects my larger point much."
> Sorry, but could you tell me again your objections?

That "systems subject to Darwinian evolution" isn't much better defined
than "life" is. Mostly because Darwinian evolution requires imperfect
replication, but not TOO imperfect replication, and that there probably
isn't a single value at which a "switch" happens.

>
> "As all things with computers it all has to come down to series of
> ones and zeros at some point, but at the end of the day they're
> entities that replicate imperfectly, which is what your vesicles are
> right?"
> - First, my model has nothing to do with a computer approach.

I never said it did. But a computer approach modelling the evolution of
abstract replicators can apply to the evolution of many different kinds
of replicators, so your objection that your vesicles don't use nucleic
acids is completely irrelevant.

> - Second, the fact that the vesicles are able to reproduce is not a
> specific property of my model as the current experimental vesicles are
> able to reproduce too.
> - Third, the specificity of my vesicles is that they are able to
> transmit specific characteristics (related to specific phenotypic
> properties) to their descendants.
>

When I say "replicate" or "reproduce" I implicitly mean "pass on
specific characteristics to their descendants". That's why I talked
about the fidelity of replication or reproduction.

Maybe you should tell me what you think a few minimal criteria for
Darwinian evolution are, because I've been going on about imperfect
replication as if it were an obvious one but maybe you disagree on that.

[marc.t...@wanadoo.fr]

Actually I think Darwinian evolution is possible: there is no absolute
requirement of a kind of mutations (i.e. changes) for natural
selection operating. If the model allows the emergence of several
distinct lineages of vesicles then natural selection can operate on
these lineages. Of course, if a kind of mutation is possible then the
number of distinct lineages would be much higher, during a period of
time much shorter. Then Darwinian evolution would be much faster and
much more efficient.

"So... there IS change."
At the beginning I didn't realise that the model had the capacity for
a a kind of mutations but, later on, I found out it actually had it.

"And how do you go from non-replicating vesicles to near-perfectly
replicating vesicles ?"

- The vesicles reproduce by simple division.
- However the lipid composition of their membrane is not stable: this
composition is fully dependent on the nutriments provided by the
environement.
- Then vesicles do not self-replicate.
- Only some specific characteristics replicate and are hereditary:
specific membrane sites and specific molecules. Each membrane site/
molecule couple forms a mutually catalytic process which is the most
simple hypercycle you can imagine.
- These site/molecule couples represent the hereditary information.

[marc.t...@wanadoo.fr]

be'"false'"
A distinction can be proved to be false if it is possible to draw a
precise and commonly accepted boundary between living and nonliving
systems.

"Mostly because Darwinian evolution requires imperfect replication,
but not TOO imperfect replication, and that there probably isn't a
single value at which a "switch" happens."

See the last point.

"Maybe you should tell me what you think a few minimal criteria for
Darwinian evolution are, because I've been going on about imperfect
replication as if it were an obvious one but maybe you disagree on
that."

There are three conditions:
1. Local conditions allowing the emergence of dissipative systems,
organized on a macroscopic level, generated by a flow of matter and
energy that is continuously supplied. These open far-from-equilibrium
systems are self-sustained and thus can maintain themselves far-from-
equilibrium because they are able to exchange energy, matter, and
information with the external environment;
2. The systems must be able to reproduce;
3. The systems must be capable of acquiring heritable structure/
function properties that are relatively independent from the local
environment, i.e., the fact that they belong to a specific lineage
should not depend on the nature of the nutriments they receive from
the local environment. This last condition is required for the
emergence of distinct lineages allowing natural selection.

[Arkalen]

Of course natural selection doesn't require mutations. Thing is, without
mutation there are no distinct lineages. Or if you're thinking of
distinct lineages that arose independently (not from a common ancestor),
those lineages *don't change*. Once something is culled by natural
selection it's gone, and the remaining lineages don't diversify to
compensate for the loss in diversity. And in fact, given at generation
zero the individuals aren't very-well adapted to the environment at all,
given enough time every single one of those unchanging lineages will be
wiped out and that's all she wrote.

Basically what you have is evolution over one generation only. And
that's no evolution at all.

> Of course, if a kind of mutation is possible then the
> number of distinct lineages would be much higher, during a period of
> time much shorter. Then Darwinian evolution would be much faster and
> much more efficient.

I am baffled as to how Darwinian evolution could happen at all without
mutation. Maybe you could explain. And without mutation, how does your
number of "distinct lineages" go higher than one ? If they all arise
independently it's not evolution; there's no progression.

>
> "So... there IS change."
> At the beginning I didn't realise that the model had the capacity for
> a a kind of mutations but, later on, I found out it actually had it.
>
> "And how do you go from non-replicating vesicles to near-perfectly
> replicating vesicles ?"
> - The vesicles reproduce by simple division.
> - However the lipid composition of their membrane is not stable: this
> composition is fully dependent on the nutriments provided by the
> environement.
> - Then vesicles do not self-replicate.
> - Only some specific characteristics replicate and are hereditary:
> specific membrane sites and specific molecules. Each membrane site/
> molecule couple forms a mutually catalytic process which is the most
> simple hypercycle you can imagine.
> - These site/molecule couples represent the hereditary information.
>

And how much simpler are these site/molecule couples than ribosomes/RNA?
And if they're as simple as I can imagine, how come no abiogenesis lab
has come upon them yet ?

Besides I'm not seeing the difference between those vesicles and any
other hypothesized kind of proto-cell, or what the difference of your
approach is in practice. Lots of people are looking at precursors for
life that don't use DNA or even RNA, and they don't worry about whether
they're looking at the origin of "life" or "Darwinian evolution".

[John S. Wilkins]

No, I meant "they are doing [science by definition]" not "they are doing
science [by definition]". I had not noticed the ambiguity myself...

[John S. Wilkins]

Friar Broccoli <eli...@gmail.com> wrote:

> On 2012-02-12 02:36, John S. Wilkins wrote:
> > Bill<broger...@gmail.com> wrote:
> >
> >> On Feb 11, 11:50 am, Friar Broccoli<elia...@gmail.com> wrote:
> >>> On 2012-02-10 19:01, John S. Wilkins wrote:
> > ....
> >>>> You are making a mistake here that is quite common: confusing studying a
> >>>> thing with defining it. We can study things we do not know how to
> >>>> define, and we can define things that are not (scientifically)
> >>>> investigable, like unicorns and fairies.
> >>>
> >>> Is this an example of "category error"? Or does it belong in a (or
> >>> perhaps several) different philosophical "box(es)"?
> >
> .
>
> > There are indefinitely many ways to carve up errors in reasoning,
> > because an error is the absence of correctness, and you can divide
> > privative classes many ways.
> >
> > Taxonomies of fallacies are in general unenlightening.
>
> Useful comment, which helps me understand why I have found the effort to
> produce such a classification system so frustrating.
>
> I had thought my problem was an absence of any understanding of the
> basic rules of logic.

Check out

Hamblin, C. L. 1970. Fallacies. London: Methuen.


An analogy is this: how many ways are there to make a mistake in, say,
mathematics? Can we classify them all?

>
>
> >>>
> >>
> >> You are making a mistake that is quite common here. We can refute
> >> errors without categorizing them.
> >
> > Unless you are making some kind of mistake in saying that :-)


--

[Burkhard]

On Feb 12, 9:10 pm, j...@wilkins.id.au (John S. Wilkins) wrote:
> Friar Broccoli <elia...@gmail.com> wrote:
> > On 2012-02-12 02:36, John S. Wilkins wrote:

> > > Bill<brogers31...@gmail.com>  wrote:

>
> > >> On Feb 11, 11:50 am, Friar Broccoli<elia...@gmail.com>  wrote:
> > >>> On 2012-02-10 19:01, John S. Wilkins wrote:
> > > ....
> > >>>> You are making a mistake here that is quite common: confusing studying a
> > >>>> thing with defining it. We can study things we do not know how to
> > >>>> define, and we can define things that are not (scientifically)
> > >>>> investigable, like unicorns and fairies.
>
> > >>> Is this an example of "category error"?  Or does it belong in a (or
> > >>> perhaps several) different philosophical "box(es)"?
>
> >   .
>
> > > There are indefinitely many ways to carve up errors in reasoning,
> > > because an error is the absence of correctness, and you can divide
> > > privative classes many ways.
>
> > > Taxonomies of fallacies are in general unenlightening.
>
> > Useful comment, which helps me understand why I have found the effort to
> > produce such a classification system so frustrating.
>
> > I had thought my problem was an absence of any understanding of the
> > basic rules of logic.
>
> Check out
>
> Hamblin, C. L. 1970. Fallacies. London: Methuen.
>
> An analogy is this: how many ways are there to make a mistake in, say,
> mathematics?

648. Unless you are in Indiana, then it is 649.

> Can we classify them all?
>
>
>
> > >> You are making a mistake that is quite common here. We can refute
> > >> errors without categorizing them.
>
> > > Unless you are making some kind of mistake in saying that :-)
>
> --

> John S. Wilkins, Associate, Philosophy, University of Sydneyhttp://evolvingthoughts.net

[Bob Casanova]

On Sat, 11 Feb 2012 10:18:44 -0800 (PST), the following
appeared in talk.origins, posted by marc.t...@wanadoo.fr:

>On 11 fév, 18:53, Bob Casanova <nos...@buzz.off> wrote:
>> On Sat, 11 Feb 2012 06:09:13 -0800 (PST), the following
>> appeared in talk.origins, posted by marc.tess...@wanadoo.fr:

>>
>> >"A single cell is a life form even if a virus may not be"
>> >I suppose that, by "a cell", you mean a complex vesicle with all the
>> >genetic machinery?

>> >But what about lipid vesicles without this complex genetic machinery
>> >but nevertheless with the capacity to reproduce and to transmit some
>> >of their caracteristics to their daughter vesicles: are they living?
>>
>> As others have pointed out, definitions are sometimes
>> tricky. Do you think that everything that exists has a fixed
>> and unique definition? If you do, you're mistaken. The lack
>> of a universally-recognized and fixed definition for "life"
>> is no real handicap for those investigating abiogenesis
>> since they're investigating natural processes, not
>> dictionaries.
>>
>> And please learn to set up attributions; it makes the thread
>> much easier to follow. No, I don't know how to do this in a
>> post via GurgleGroups, but I'm sure there's a help file.

>"As others have pointed out, definitions are sometimes tricky."
>Ok, but usually definitions help, particularly in science. In
>mathematics, for instance, definitions are a prerequisite.
>Indeed I just ask the following question: Are lipid vesicles without
>the complex genetic machinery but with the capacity to reproduce and
>to transmit some of their characteristics to their daughter vesicles
>'living' systems? The answer can be: "yes" or "no" or "I don't know".

I don't know about your particular example, but I believe
the answer regarding viruses is exactly as you surmised:
"yes" or "no" or "I don't know".

>Of course any arguments with the response would be welcome.
--

Bob C.

"Evidence confirming an observation is
evidence that the observation is wrong."
- McNameless

[Arkalen]

Doesn't "a precise and commonly accepted boundary between living and
nonliving systems" count as a "distinction" ? If so what you've just
said makes no sense, unless you mean that a *particular* distinction is
false if and only if there actually exists a distinction that's true,
and it's not that particular one.

And that's begging the question. You've just shown how to tell whether a
distinction is true on its own merits (presumably, "it draws a precise
and commonly accepted boundary between living and nonliving systems").
Therefore we should also be able to tell whether a distinction is false
on its own merits. (such as, "it does not draw a precise and commonly
accepted boundary between living and nonliving systems").

>
> "Mostly because Darwinian evolution requires imperfect replication,
> but not TOO imperfect replication, and that there probably isn't a
> single value at which a "switch" happens."
> See the last point.
>
> "Maybe you should tell me what you think a few minimal criteria for
> Darwinian evolution are, because I've been going on about imperfect
> replication as if it were an obvious one but maybe you disagree on
> that."
> There are three conditions:
> 1. Local conditions allowing the emergence of dissipative systems,
> organized on a macroscopic level, generated by a flow of matter and
> energy that is continuously supplied. These open far-from-equilibrium
> systems are self-sustained and thus can maintain themselves far-from-
> equilibrium because they are able to exchange energy, matter, and
> information with the external environment;
> 2. The systems must be able to reproduce;
> 3. The systems must be capable of acquiring heritable structure/
> function properties that are relatively independent from the local
> environment, i.e., the fact that they belong to a specific lineage
> should not depend on the nature of the nutriments they receive from
> the local environment. This last condition is required for the
> emergence of distinct lineages allowing natural selection.
>

Okay. So the fidelity of replication is indeed relevant. In other words,
how reliable does the inheritance process have to be to get Darwinian
evolution ?

Other question : evolving systems adapt to evolutionary pressures. One
simple evolutionary pressure on your basic replicators is the error rate
of replication - in an environment with a high rate of error in
replication, those with a lower error rate will spread. And most
abiogenesis hypotheses I've seen proposed replicating systems that
started out highly error-prone, and evolved ways of replicating more
faithfully (and error-correction mechanisms would account for a lot of
modern cells' complexity).

Apparently there are also issues with Muller's ratchet - there are upper
limits on the complexity evolution can achieve, which go higher when
replication has fewer errors. That also suggests that the error rate of
replication generally went down, not up.

You however apparently start out with systems that already replicate
perfectly, or near it. What selection pressures are they under ?

[marc.t...@wanadoo.fr]

On 12 fév, 22:08, Arkalen <arka...@inbox.com> wrote:

You are right:" If they all arise independently it's not evolution;

there's no progression".

Actually several possibilities of relationships between the lineages
and/or between the membrane site/molecule couples are allowed by the
model:
- first there can be fusions of two vesicles: then the combined
results are vesicles with both types of membrane site/molecule
couples;
- second the sites can migrate onto the inner part of the membrane
with a possible linkage between two sites, leading to the formation of
a more complex site which can favor the polymerisation of simple
molecules, then multiply the possibilities for new compounds with new
properties, particularly if the simple molecule is an AMINO-ACID!
- third a site doesn't catalyse the synthesis of ONE molecule actually
but of A CLASS of molecules: then numerous molecules with different
properties are provided.

"And how much simpler are these site/molecule couples than ribosomes/
RNA?"

I don't think that the synthesis of ribosomes/RNA is simple without
any catalysts, particularly because of the problem of the required
enantioselectivity.
Moreover, in the conditions required for the emergence of open far-
from-equilibrium self-sustained systems, that can maintain themselves
far-from-equilibrium because they are able to exchange energy, matter,
and information with the external environment, such as hydrothermal
vents (e.g. the serpentinite-hosted Lost City Hydrothermal Field), the
high temperature is fully deleterious for ribosomes/RNA.

"And if they're as simple as I can imagine, how come no abiogenesis
lab has come upon them yet ?"

First nobody until now has tested such an hypothesis.
Second the emergence of membrane site/molecule couples are not trivial
occurrences.

"Lots of people are looking at precursors for 'life' that don't use
DNA or even RNA, and they don't worry about whether they're looking at
the origin of 'life' or 'Darwinian evolution'."

Not a lot. Labs working on the ribosomes/RNA approach are the majority
because they want to reproduce the 'life' as we know it.
The other labs have a major problem when working outside the ribosomes/
RNA approach: the problem of the emergence of distinct lineages. In
addition these labs want to reproduce the metabolism as we know it.

[David Hare-Scott]

marc.t...@wanadoo.fr wrote:
> On 12 fév, 01:21, j...@wilkins.id.au (John S. Wilkins) wrote:
>> <marc.tess...@wanadoo.fr> wrote:
>>> "We can study things we do not know how to define"
>>> I would be grateful if you could give us examples of material,
>>> physical (in one word 'real') things that scientists cannot define
>>> scientifically but that they can study?
>>
>> Life
>>
>> Gene
>>
>> Species
>>
>> Region
>>
>> Niche
>>
>> Mountain
>>
>> Ecosystem
>>
>> Disease
>>
>> Society
>>
>> Cognition
>>
>> Planet
>>
>> Star
>>
>> Galaxy
>>
>> Cloud
>>
>> Climate
>>
>> ...
>>
>>
>>

>>> "We do not have to be able to define "life", so long as we can point
>>> to standard examples of life. I can point to my children and say

>>> "life is like *them"
>>> Your example (your children) belong to the category of "animals".
>>> Indeed animals are among the most sophisticated extant terrestrial
>>> systems being the outcome of more than 4 billions years of Darwinian
>>> evolution! Then it is easy to say that they are different from,
>>> let's say, minerals. Nevertheless, among the extant terrestrial
>>> systems stemming from Darwinian evolution, there are also virus and
>>> above all prions, for which the status of 'living' systems is very
>>> much debated, isn't it?
>>
>> Animals are alive if anything is. So what?
>>
>>> The other major issue with the concept of life, as you admitt it
>>> ("at no stage is there a discrete step from "not-life" to "life"),
>>> is the miraculous moment when nonliving systems would have become
>>> living.
>>
>> Objection, your worship. Facts not admitted in evidence!
>>
>>> Moreover I would appreciate your reply to my statement that the
>>> hypothesis that any such boundary or moment exists is not
>>> falsifiable because no experiment can be envisaged to prove it to
>>> be false.
>>
>> That is, to be sure, the very definition of "not falsifiable". But
>> it is
>> not required for there to be a fact of living systems. Look up
>> "black and white" fallacy, and "sorites".
>>
>>
>>

>>> "By the way, the people who seem to want a definition of life most

>>> ardently are the exobiologists at NASA, who think, wrongly, that if
>>> they can define the sorts of chemical reactions and dynamics that
>>> all and only life can do, they can build a detector for their

>>> probes." You don't give your reasons why exobiologists at NASA are
>>> wrong, do you?
>>> These scientists are not the only ones who seem to want a definition
>>> of life: scientists who are working on the origin of life too!
>>

>> Really? I had no idea:
>>
>> http://www.springerlink.com/content/h475867185551688/

>> --
>> John S. Wilkins, Associate, Philosophy, University of
>> Sydneyhttp://evolvingthoughts.net But al be that he was a
>> philosophre,
>> Yet hadde he but litel gold in cofre
>

> I begin by what I am the most interested in your response: I would be

> grateful if you could send me the pdf of your article entitled

> "Selection without replicators: the origin of genes, and the

> replicator/interactor distinction in etiobiology.": I would like to
> read it and send you my comments if you like it.
>
> Your examples of material, physical (in one word 'real') things that
> scientists cannot define scientifically but that they can study:
> - Life: for me it is a metaphysical concept;

> - Species: as Arkalen is saying, there are "different definitions of
> 'species' that apply to different situations and then there are
> situations where scientists avoid the word entirely";

> - Region: I supposed you mean that we cannot define an absolute
> boudary for a 'region' in general but we must for a specific region;
> - Niche: aproximatively the same situation as for 'species''
> - Mountain: I supposed you mean that we cannot define an absolute
> distinction between these different categories as 'rise in the
> ground', 'hill', 'mountain' etc. However, when scientists are dealing
> with such a specific 'rise in the ground' they will specify its
> altitud accurately;

> - Ecosystem: it is true that such a concept is vague but when
> scientists are dealing with it they must specify their definition for
> the given situation they are studying;
> - Disease: I am physician and I can assert that physicians must define
> a particular disease when they study it (e.g. consensus documents such
> as the consensus document of The Joint European Society of Cardiology/
> American College of Cardiology Committee for the redefinition of
> myocardial infarction);
> - Society: the same as for 'Ecosystem';
> - Cognition: the same as for 'Ecosystem';
> - Planet: a clear definition exists!

> - Star: the same as for 'planet'!
> - Galaxy: the same as for 'planet'!
> - Cloud: the same as for 'Ecosystem';
> - Climate: the same as for 'Ecosystem'.
> I am a little puzzled by your view of what science is: is it because
> you are a philosopher? For me 'philopsophy' is between science and
> metaphysics: why didn't you choose 'philosophy' in your examples?
>
> Animals:
> You do not want to see the point: the fact you are taking the example
> of the most complex extant terrestrial systems which is the result of
> more than 4 billion years of Darwinian evolution and that it is far
> easier that to make a distinction with minerals than for prions, for
> example!
>

> "The miraculous moment when etc."
> Sorry, but I do not understand your objection and what you are meaning
> by "Facts not admitted in evidence!": can you specify it?
>
> Fasifiability of the concept of life:
> "Black-or-white fallacy is a false dilemma fallacy that unfairly
> limits you to only two choices" (Internet Encyclopedia of
> Philosophy).
> The distinction between nonliving and living systems is not a false

> dilemma fallacy: it is necessary if you want to know something about
> the origin of life.

Now we are back at the start again and you haven't said anything about why
you have this problem, you just reiterate that you do.

Some things have all the attributes of living (you and me), some have none
(a litre of hydrogen) and some have a few and seem ambiguous (a crystal of
tobacco mosaic virus). Why is it that using a list of attributes is not
adequate for the purpose of study? Do you think that the vagueness in
between the extremes means we know nothing?

Consider an exobiologist who (hypothetically) isolates a boojum from the
soil of mars and says it has such and such attributes of life but not
others. This information adds to the stock of knowledge and bears on the
question of how and where and when life originated even if it is not
possible to say categorically if the boojum is alive or not.

Your problem is with words. The nature of the universe is independent of
humans having the right words, it is whatever it is. But to you some parts
are off limits for study because of ambiguities in words. How bizarre.


David

[Mark Isaak]

On 2/12/12 1:21 AM, marc.t...@wanadoo.fr wrote:
> [...]

> Fasifiability of the concept of life:
> "Black-or-white fallacy is a false dilemma fallacy that unfairly
> limits you to only two choices" (Internet Encyclopedia of
> Philosophy).
> The distinction between nonliving and living systems is not a false
> dilemma fallacy: it is necessary if you want to know something about
> the origin of life.

On the contrary, it is necessary to *disregard* a distinction between
living and nonliving if you want to know something about the origin of
life. At some stage (almost certainly), as nonlife progressed to
protolife progressed to life, the whatever-it-was was neither fully
living nor fully non-living. It was in the gray area. If you insist on
the black/white distinction, then you restrict yourself from looking at
that stage. And that stage is quite probably the most important in the
process.

Suppose you wanted to know the origin of New York City. A researcher
tells you, "Well, we can look at the area when there were just a few
houses, and we can look at the area when it had become a metropolis, but
scattered houses and metropolis are the only things we can consider if
we want to know something about the origin of New York City." Does that
really make any sense to you?

--
Mark Isaak eciton (at) curioustaxonomy (dot) net
"It is certain, from experience, that the smallest grain of natural
honesty and benevolence has more effect on men's conduct, than the most
pompous views suggested by theological theories and systems." - D. Hume

[marc.t...@wanadoo.fr]

On 13 fév, 02:27, Mark Isaak <eci...@curioustaxonomyNOSPAM.net> wrote:

"Suppose you wanted to know the origin of New York City. etc."
The example is good: I think the concept of "New York City" is
arbitrary because nobody can assert for sure that the entity "New York
City" began at a precise time, except if we consider that the first
livings on the site of the future "New York City" could have been
named "New York City" already and this is not true. This is the kind
of entities which has only a meaning for human beings ... like
'life'!
So you are right: cities are entities which are r

[marc.t...@wanadoo.fr]

On 12 fév, 23:37, "David Hare-Scott" <sec...@nospam.com> wrote:

> >> Sydneyhttp://evolvingthoughts.netBut al be that he was a

I agree with this statement. That is why I consider the concept of
'life' as an arbitrary concept because it has a meaning only for human
beings.

[James Beck]

On Sun, 12 Feb 2012 17:23:21 +0100, Athel Cornish-Bowden

It wasn't a point exactly. Take it as a compliment.

>Maybe you took my comment as
>being sarcastic, but it wasn't intended to be. Actually I now realize
>that the sentence i liked ("I think they are doing science by
>definition") is ambiguous in a way that I hadn't previously noticed. I
>took it as echoing a previous sentence ("The desire for a hard and fast
>definition is a hangover from the days when people tried to do science
>by definition") that was clearly not intended to treat "science by
>definition" as something good. I still think that is probably what John
>Wilkins meant, but the sentence could be read to mean that by the
>definition of science what these people are doing is science. If that
>is what he meant then I don't agree.

Most people glide over sentences like that without giving them a
second thought. I did. To the benefit of the species, some, like you,
do not. My first thought was to disagree with your assessment; my
natural inclination is toward nicely crystallized thoughts and things
that are immediately useful. Not that I wasn't already aware that John
Wilkins sees biology as chemistry, and chemistry as physics, but in
this passage he said that particularly well. It was short, to the
point, and consistent with his known view; I found it very clear and
rational, a snippet of beauty that says something I would like to have
said in that, or a very similar way.

As I said, my first thought was to simply disagree, but upon
reflection, I couldn't. It's not wrong, but the passage is unpolitic,
so my second thought was that a wise editor would say to leave it out.
My third thought was to ask you to elaborate on your comment, because
JW's statement is as you say, subject to different interpretations. I
decided against that because it imposes a burden on you.

A day of happy thinking elapsed between here and there, so instead, I
chose to pay you a compliment for noticing right off that there's
something jarring going on there, and let it go at that. That went
awry; I suppose no one wants to be complimented for having
inadvertently affirmed that he beats his wife, so I elicited an
elaboration anyway.

Appropriately, your elaboration both affirms and negates the sentence,
a good indication that you know what is going on and that you are, as
I said, a troublemaker. To say that one does science by definition is,
I think, a sort of non-trivial dialetheia, i.e., both it and its
negation are true. Trivially, one might say that models always start
somewhere, to which comes the reply, but not too rigidly. That sets up
a modern koan. The student asks, "Master, why did you do science from
rigid definition," and the Master replies, "Because it set me free."

It's a convoluted, self-referential demon that covers a lot of ground
from pernicious early optimization, to the kluge-and-ex-post
rationalization. When our definitions are working, we call it
orthodoxy. When they aren't working so well or we're between
redefinitions, we call it baloney slicing. It falls to JW to explain
the paraconsistency of his demon in a nice paper or two.

Anyway, I agree that it is the most interesting sentence. Whether it
is the best one is a matter of preference. It reminds me of a famous
Chinese curse.

[James Beck]

On Sun, 12 Feb 2012 01:27:31 -0800 (PST), marc.t...@wanadoo.fr
wrote:

>On 12 fév, 05:00, James Beck <jdbeck11...@yahoo.com> wrote:
>> On Sat, 11 Feb 2012 11:31:04 +0100, Athel Cornish-Bowden
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> <acorn...@imm.cnrs.fr> wrote:
>> >On 2012-02-11 01:39:15 +0000, James Beck said:
>>

>> >> On Sat, 11 Feb 2012 11:01:23 +1100, j...@wilkins.id.au (John S.
>> >> Wilkins) wrote:

>Thank you for your congratulations.

Even on your planet, it is almost certainly considered rude to step up
for compliments directed to someone else. Please don't do it again.

[R. Dean]

On 02/11/2012 07:08 AM, Steven L. wrote:
> "marc.t...@wanadoo.fr" <marc.t...@wanadoo.fr> wrote in message
> news:a11c3a2c-aec8-4c02...@v2g2000vbx.googlegroups.com:

>
>> Actually there is a seeming consensus among the specialists in the
>> search for the origin of life (chemists, geochemists, biochemists,
>> biologists, exo/astrobiologists, computer scientists, philosophers and
>> historians of science) that there is an "obvious need for a definition
>> of life". In spite of this wish everybody can observe the amazingly
>> high number of definitions of life, leading to reflect that skepticism
>> is multiplied by the above number, leaving almost no chance for new
>> formulations which, however, continue to appear!
>> Wouldn't be that any definition of life is subjective and arbitrary as
>> is the boundary between living and nonliving systems or the moment
>> when nonliving systems would have become living? It is true that the
>> statement that any such boundary or moment exists is not falsifiable:
>> no experiment can be considered to prove that it can be false.
>> Therefore, if the distinction between living and nonliving systems is
>> a matter of belief and not science, it is not only hopeless but
>> useless to try to define this indefinable state related to a
>> metaphysical question!
>> If the concept of life is metaphysical then, it is true to say that we
>> can know nothing about the origin of life, as it is true to say that
>> we can know nothing about the origin of the soul, about the origin of
>> God etc.
>

> Is God (if He exists) a "life form"?
>
> He is supposed to be some disembodied spirit. But science-fiction
> writers have had a field day writing about hypothetical life forms that
> exist as pure energy or something else can perform the usual functions
> of life without biochemical bodies.
>
> Nevertheless, right here on Earth, though we may argue about viruses and
> prions, there is universal agreement that things like procaryotes are
> life forms. A single cell is a life form even if a virus may not be.
>
> And how the first cell got started is still a legitimate scientific
> question.
>
It seems that the origin of life research was red hot just after the
Urey - Miller experiment, but little or no further "earth-shaking"
successful experimental light has been shown on the origin of life; this
is not to say there is none, but none of the lofty magnitude of the '53
experiment. .
>
>
>
> -- Steven L.
>
>

[Athel Cornish-Bowden]

OK. So I understood you correctly, and I agree.


--
athel

[marc.t...@wanadoo.fr]

On 12 fév, 22:30, Arkalen <arka...@inbox.com> wrote:

> perfectly, or near it. What selection pressures are they under ?- Masquer le texte des messages précédents -
>
> - Afficher le texte des messages précédents -- Masquer le texte des messages précédents -
>
> - Afficher le texte des messages précédents -

"Doesn't "a precise and commonly accepted boundary between living and
nonliving systems" count as a "distinction" ? If so what you've just
said makes no sense, unless you mean that a *particular* distinction
is false if and only if there actually exists a distinction that's
true, and it's not that particular one."

I think that nobody can find an experiment or an observation to prove
that a given distinction exists, or to say more scientifically, that
nobody can find an experiment or an observation to prove that a given
distinction is false, whatever the distinction.
For example I would like to find an experiment or an observation to
prove that the following distinction is false: "living systems are
systems which have at least the capacity to reproduce, to transmit
some of their characteristics to their descendents and to show some
metabolism".
Depending of the definition of life I choose I can refute or not such
a distinction:
1) if my definition of living systems contains the viruses the
distinction is refuted as viruses reproduce and transmit their
characteristics to their descendents but have no metabolism;
2) on the contrary if my definition of living systems doesn't contain
the viruses the distinction is not refuted.
This example is just to illustrate that the refutation of any
distinction by any experiment or observation is totally depending on
the definition of life you choose. That is why I say that the
existence of any distinction is not falsifiable.

"You however apparently start out with systems that already replicate
perfectly, or near it. What selection pressures are they under ?"

I hypothesize that some of the molecules of the membrane site/molecule
couples may interact with the vesicle membrane, such as they improve
the stability of the vesicle membrane or the rate of reproduction, or
facilitate the adherence between vesicles and so on ...
These are phenotypic properties that natural selection can favor.

[Burkhard]

That is in the nature of definitions. Definitions are helpful or
unhelpful, but not true or false.

[marc.t...@wanadoo.fr]

Thus you agree with me that a distinction between living and nonliving
systems is not falsifiable, whatever the distinction.

[Arkalen]

That's like saying the distinction between living and nonliving systems
is not lavender, whatever the distinction.

I mean, I guess technically it's true, but only because "lavender" isn't
the kind of attribute that applies to those things in the first place.

But let's say that okay, the distinction isn't falsifiable because
definitions, not being "true" or "false", can't be "falsifiable" either.
As far as I can tell this whole thing started when you said that life to
you was metaphysical, and "metaphysical" was things that weren't
amenable to science, and that's where "not falsifiable" came into play.

So are you basically saying that science cannot make definitions ? That
all definitions are inherently metaphysical ?

[Burkhard]

No definition is falsifiable, that includes the definition of
evolution. Definitions are helpful and necessary, but not that
interesting really.

[marc.t...@wanadoo.fr]

On 13 fév, 21:11, Arkalen <arka...@inbox.com> wrote:

I see the trap! However the question is interesting.
Definitions of phenomenons in physics are useful but it is much better
to understand the mechanisms underlying the phenomenons.
This why Darwinian evolution, which is a process, can be well
characterised.
On the contrary, saying that a system is 'living' would characterise a
special state of the system and not really a process. If life could be
characterised by an univocal process or mechanism, like Darwinian
evolution, the problem of the concept of life would be solved.

[marc.t...@wanadoo.fr]

> > "That is in the nature of definitions. Definitions are helpful or
> > unhelpful, but not true or false."
> > Thus you agree with me that a distinction between living and nonliving
> > systems is not falsifiable, whatever the distinction.
>
> No definition is falsifiable, that includes the definition of
> evolution. Definitions are helpful and necessary, but not that
> interesting really.

Darwinian evolution is a process.
Such a process requires some conditions.
I suggest that only three conditions are necessary and sufficient:

[John S. Wilkins]

Burkhard <b.sc...@ed.ac.uk> wrote:

> On Feb 13, 7:44 pm, marc.tess...@wanadoo.fr wrote:
> > On 13 fév, 20:02, Burkhard <b.scha...@ed.ac.uk> wrote:

...

> > > > This example is just to illustrate that the refutation of any
> > > > distinction by any experiment or observation is totally depending on
> > > > the definition of life you choose. That is why I say that the
> > > > existence of any distinction is not falsifiable.
> >
> > > That is in the nature of definitions. Definitions are helpful or
> > > unhelpful, but not true or false.

...

> >
> > "That is in the nature of definitions. Definitions are helpful or
> > unhelpful, but not true or false."
> > Thus you agree with me that a distinction between living and nonliving
> > systems is not falsifiable, whatever the distinction.
>
> No definition is falsifiable, that includes the definition of
> evolution. Definitions are helpful and necessary, but not that
> interesting really.

Definitions are correct or incorrect, precise or vague. But distinctions
made about the natural world are accurate or not, true or false. If I
say something like "All mammals have hair", this is not a definition,
but it is a distinction that can easily be falsified by finding one that
doesn't (a cetacean, for instance).

If I say "living things are X, Y, and Z", that is a distinction; and it
may be falsified by finding something held to be alive that only
occasionally has Z (like living things that do *not* reproduce, such as
my brother, who is, by all accounts, very much alive). It is also a
vague distinction when we get to self-reproducing lipid vesicles and
viroids. But it has a purchase in the real world where "all bachelors
are unmarried men" doesn't.

[John S. Wilkins]

A random selection from my endnote database:

Ertem, G., and J. P. Ferris. 1996. Synthesis of RNA oligomers on
heterogeneous templates. Nature 379 (6562):238–240.

Fox, S. W. 1972. Molecular evolution and the origin of life. San
Francisco: Freeman.

Huber, C. , and G. Wachtershauser. 1998. Peptides by activation of amino
acids with CO on (Ni,Fe)S surfaces: implications for the origin of life.
Science 281 (5377):670–672.

Huber, C., and G Wächtershäuser. 1997. Activated acetic acid by carbon
fixation on (Fe,Ni)S under primordial conditions. Science 276
(5310):245–247.

James, K. D., and A. D. Ellington. 1997. Surprising fidelity of
template-directed chemical ligation of oligonucleotides. Chemistry and
Biology 4 (8):595–605.

Kochavi, E., A. Bar-Nun, and G. Fleminger. 1997. Substrate-directed
formation of small biocatalysts under prebiotic conditions. Journal of
Molecular Evolution 45 (4):342–351.

Levy, M., and S. L. Miller. 1998. The stability of the RNA bases:
implications for the origin of life. Proceedings of the National Academy
of Sciences of the United States of America 95 (14):7933–7938.

Miyakawa, Shin, H. James Cleaves, and Stanley Miller. 2002. The Cold
Origin of Life: A. Implications Based On The Hydrolytic Stabilities Of
Hydrogen Cyanide And Formamide. Origins of Life and Evolution of
Biospheres 32 (3):195-208.

Nowak, Martin A., and Hisashi Ohtsuki. 2008. Prevolutionary dynamics and
the origin of evolution. Proceedings of the National Academy of Sciences
105 (39):14924-14927.

Rajamani, Sudha, Justin K. Ichida, Tibor Antal, Douglas A. Treco, Kevin
Leu, Martin A. Nowak, Jack W. Szostak, and Irene A. Chen. 2010. Effect
of Stalling after Mismatches on the Error Catastrophe in Nonenzymatic
Nucleic Acid Replication. Journal of the American Chemical Society 132
(16):5880-5885.

Szathmáry, Eörs. 2006. The origin of replicators and reproducers.
Philosophical Transactions of the Royal Society B: Biological Sciences
361 (1474):1761-1776.

Wächtershäuser, G. 1997. The origin of life and its methodological
challenge. Journal of Theoretical Biology 187 (4):483–494.

Yao, Shao, Indraneel Ghosh, Reena Zutshi, and Jean Chmielewski. 1998.
Selective amplification by auto- and cross-catalysis in a replicating
peptide system. Nature 396:447-450.

I don't know what you count as "groundbreaking" but Sidney Fox's work
seems equal to or better than Miller-Urey, and I haven't even listed the
astrobiological work on extraterrestrial synthesis of oligomers for
life.

[Matthew Bladen]

In article <5138f2ee-77e3-4ea3-b1c5-

Don't say that! They're my bread and butter...

--
Matthew

[Burkhard]

Not sure what point you try to make here.

[marc.t...@wanadoo.fr]

On 13 fév, 22:54, j...@wilkins.id.au (John S. Wilkins) wrote:

> John S. Wilkins, Associate, Philosophy, University of Sydneyhttp://evolvingthoughts.net

> But al be that he was a philosophre,
> Yet hadde he but litel gold in cofre

"All mammals have hair" versus "Living things are X, Y, and Z"
I am sorry but the two assertions have not the same logical meaning:
- "All mammals have hair" is an exhaustive assertion of what would be
ALL "mammals": it can be falsified by the usual scientific definition
of what are "mammals";
- "Living things are X, Y, and Z" says only that X, Y, and Z are
living things but not that ALL living things are X, Y, and Z. Thus it
is not a definition of what would be ALL living things.

[Richard Norman]

[Richard Norman]

On Tue, 14 Feb 2012 08:54:52 +1100, jo...@wilkins.id.au (John S.
Wilkins) wrote:

What do you mean by saying a definition can be correct or incorrect?
Are you referring to whether it captures usage?

The problem with distinctions is when definitions are fuzzy and you
make the distinction about entities that fall within that uncertain
area. The distinction may or may not be true or false depending on
how you interpret the definition

Also distinctions in biology often have weasel words. Two organisms
are members of different species if they cannot interbreed
successfully except when they can in which case they have to do it in
the wild and even then often enough otherwise it doesn't really count
when you find the hybrids really living out there.

[marc.t...@wanadoo.fr]

cf. my answer to Arkalen I reproduce below:

[marc.t...@wanadoo.fr]

On 13 fév, 22:54, j...@wilkins.id.au (John S. Wilkins) wrote:

> R. Dean <"R. Dean"@gmail.com> wrote:
>
>
>
>
>
>
>
>
>
> > On 02/11/2012 07:08 AM, Steven L. wrote:

> > > "marc.tess...@wanadoo.fr" <marc.tess...@wanadoo.fr> wrote in message

> John S. Wilkins, Associate, Philosophy, University of Sydneyhttp://evolvingthoughts.net

> But al be that he was a philosophre,
> Yet hadde he but litel gold in cofre

Some other useful references:
Albarede, F. & Blichert-Toft, J. 2009. The terrestrial cradle of life.
In M. Gerin & M. C. Maurel (Eds.), Origins of Life: Self-Organization
and/or Biological Evolution?: 1-12. EDP Sciences: Paris, France, 2009.
Amend, J. P. & McCollom, T. M. 2009. Energetics of Biomolecule
Synthesis on Early Earth. In L. Zaikowski (Ed.), Chemical Evolution
II: From the Origins of Life to Modern Society: ACS Symposium Series,
American Chemical Society: Washington, DC, 2009.
Andrade E. From external to internal measurement: a form theory
approach to evolution. Biosystems 2000;57:49-62.
Baaske P, Weinert FM, Duhr S, Lemke KH, Russell MJ, Braun D. Extreme
accumulation of nucleotides in simulated hydrothermal pore systems.
Proc Natl Acad Sci U S A 2007;104:9346-51.
Baross J, Hoffman SE. Submarine hydrothermal vents and associated
gradient environments as sites for the origin and evolution of life.
Orig. Life Evol. Biosph. 1985;15:327-45.
Bergé, P., Pomeau Y., & Vidal, C. 1988. L'ordre dans le chaos. Edition
Hermann: Paris, France, 1988.
Brasier MD, Green OR, Jephcoat AP, Kleppe AK, Van Kranendonk MJ,
Lindsay JF, Steele A, Grassineau NV. Questioning the evidence for
Earth's oldest fossils. Nature 2002;416:76-81.
Budin I, Bruckner RJ, Szostak JW. Formation of protocell-like vesicles
in a thermal diffusion column. J Am Chem Soc 2009;131:9628-9.
Chen IA, Walde P. From self-assembled vesicles to protocells. Cold
Spring Harb.Perspect Biol 2010;2:a002170.
Deamer D, Dworkin JP, Sandford SA, Bernstein MP, Allamandola LJ. The
first cell membranes. Astrobiology. 2002;2:371-81.
Eigen M, Schuster P. The hypercycle. A principle of natural self-
organization. Part A: Emergence of the hypercycle. Naturwissenschaften
1977;64:541-65.
Gayon J. Defining life: synthesis and conclusions. Orig.Life
Evol.Biosph. 2010;40:231-44.
Hagmann M. Gunter Wachtershauser profile. Between a rock and a hard
place. Science 2002;295:2006-7.
Kelley DS, Karson JA, Fruh-Green GL, Yoerger DR, Shank TM, Butterfield
DA, Hayes JM, Schrenk MO, Olson EJ, Proskurowski G, Jakuba M, Bradley
A, Larson B, Ludwig K, Glickson D, Buckman K, Bradley AS, Brazelton
WJ, Roe K, Elend MJ, Delacour A, Bernasconi SM, Lilley MD, Baross JA,
Summons RE, Sylva SP. A serpentinite-hosted ecosystem: the Lost City
hydrothermal field. Science 2005;307:1428-34.
Konn C, Charlou JL, Donval JP, Holm NG, Dehairs F, Bouillon S.
Hydrocarbons and oxidized organic compounds in hydrothermal fluids
from Rainbow and Lost City ultramafic-hosted vents. Chemical Geology
2009;258:299-314.
Lane N, Allen JF, Martin W. How did LUCA make a living? Chemiosmosis
in the origin of life. Bioessays 2010;32:271-80.
Lazcano A. Which way to life? Orig.Life Evol.Biosph. 2010;40:161-7.
Ludwig KA, Kelley DS, Butterfield DA, Nelson BK, Früh-Green G.
Formation and evolution of carbonate chimneys at the Lost City
Hydrothermal Field. Geochimica et Cosmochimica Acta 2006;70:3625-45.
Luisi, P. L. 2006. The emergence of life: from chemical origins to
synthetic biology. Cambridge University Press: New York, NY, USA,
2006.
Luisi PL, Stano P, Rasi S, Mavelli F. A possible route to prebiotic
vesicle reproduction. Artificial Life 2004;10:297-308.
Martin W, Baross J, Kelley D, Russell MJ. Hydrothermal vents and the
origin of life. Nat Rev Microbiol 2008;6:805-14.
Maurer SE, Deamer DW, Boncella JM, Monnard PA. Chemical evolution of
amphiphiles: glycerol monoacyl derivatives stabilize plausible
prebiotic membranes. Astrobiology. 2009;9:979-87.
McKay CP. The search for life in our Solar System and the implications
for science and society. Philos.Transact.A Math.Phys Eng Sci
2011;369:594-606.
Monnard PA, Deamer DW. Membrane self-assembly processes: steps toward
the first cellular life. Anat Rec 2002;268:196-207.
Namani T, Deamer DW. Stability of model membranes in extreme
environments. Orig.Life Evol.Biosph. 2008;38:329-41.
Nisbet EG, Sleep NH. The habitat and nature of early life. Nature
2001;409:1083-91.
Oyama, S., Griffiths, P. E., & Gray, R. D. 2001. Cycles of
contingency: Developmental systems and evolution. MIT Press:
Cambridge, MA, USA, 2001.
Proskurowski G, Lilley MD, Seewald JS, Fruh-Green GL, Olson EJ, Lupton
JE, Sylva SP, Kelley DS. Abiogenic hydrocarbon production at lost city
hydrothermal field. Science 2008;319:604-7.
Pulselli RM, Simoncini E, Tiezzi E. Self-organization in dissipative
structures: a thermodynamic theory for the emergence of prebiotic
cells and their epigenetic evolution. Biosystems 2009;96:237-41.
Rasi S, Mavelli F, Luisi PL. Matrix effect in oleate micelles-vesicles
transformation. Orig.Life Evol.Biosph. 2004;34:215-24.
Rushdi AI, Simoneit BR. Lipid formation by aqueous Fischer-Tropsch-
type synthesis over a temperature range of 100 to 400 degrees C.
Orig.Life Evol.Biosph. 2001;31:103-18.
Russell MJ, Hall AJ, Martin W. Serpentinization as a source of energy
at the origin of life. Geobiology. 2010;8:355-71.
Schrödinger, E. 2000. What is life? With mind and matter and
autobiographical sketches. Cambridge University Press: Cambridge, New
York, NY, USA, 2000.
Schwartz AW. Arsenate DNA--Evidence for a vital force? Orig.Life
Evol.Biosph. 2011;41:1.
Segre D, Ben-Eli D, Lancet D. Compositional genomes: prebiotic
information transfer in mutually catalytic noncovalent assemblies.
Proc Natl Acad Sci U S A 2000;97:4112-7.
Shapiro R. Small molecule interactions were central to the origin of
life. Q Rev Biol 2006;81:105-125
Silver S, Phung lT. Novel expansion of living chemistry or just a
serious mistake? FEMS Microbiol Lett 2011;315:79-80.
Skar J. Introduction: self-organization as an actual theme.
Philos.Transact.A Math.Phys Eng Sci 2003;361:1049-56.
Szostak JW. An optimal degree of physical and chemical heterogeneity
for the origin of life? Phil Trans R Soc B 2011;366:2894-2901.
Tessera M. Life began when evolution began: a lipidic vesicle-based
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Tessera M. Origin of Evolution versus Origin of Life: A Shift of
Paradigm. Int J Mol Sci 2011;12:3445-58.
Tsokolov SA. Why is the definition of life so elusive? Epistemological
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Vasas V, Szathmary E, Santos M. Lack of evolvability in self-
sustaining autocatalytic networks constraints metabolism-first
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Walde P. Surfactant assemblies and their various possible roles for
the origin(s) of life. Orig.Life Evol.Biosph. 2006;36:109-50.
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Wolfe-Simon F, Blum JS, Kulp TR, Gordon GW, Hoeft SE, Pett-Ridge J,
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Bacterium That Can Grow by Using Arsenic Instead of Phosphorus.
Science 2010;

[Bill]

On Feb 14, 4:54 am, j...@wilkins.id.au (John S. Wilkins) wrote:

>
> Definitions are correct or incorrect, precise or vague. But distinctions
> made about the natural world are accurate or not, true or false. If I
> say something like "All mammals have hair", this is not a definition,
> but it is a distinction that can easily be falsified by finding one that
> doesn't (a cetacean, for instance).

How can a definition be incorrect?

<snip>

[Paul J Gans]

I've not followed this discussion in any detail. One reason is
that I think it somewhat silly. The other is that I became a
viral breeding ground over the last few days and have only lately
recovered some internal equilibrium.

But let me simply observe that the "undefinable" in science is
very very common. There are an astounding number of definitions
of "acid" in chemistry. There is even a good bit of ambiguity over
the meaning to be attached to the phrase "chemical reaction". And
I need not point out that even the often used (at least around here)
term "information" is not crystal clear in meaning.

My personal favorite is the very common word in science, "system".
It has a very different meaning in chemistry, physics, and biology.
And in chemistry at least it has no clear meaning at all. Yet
we use the term all the time and somehow muddle through.

Further, I think most here understand that clear very general
definitions are difficult in most cases.

--
--- Paul J. Gans

[Arkalen]

WTF ??? What trap ? Maybe you should tell me where it is, I'd hate to
get caught in it and then have to gnaw my leg off to escape.

> However the question is interesting.
> Definitions of phenomenons in physics are useful but it is much better
> to understand the mechanisms underlying the phenomenons.

Phenomena. Right, so you agree that having an absolute definition of
life isn't an important concern in researching its origins ?

> This why Darwinian evolution, which is a process, can be well
> characterised.
> On the contrary, saying that a system is 'living' would characterise a
> special state of the system and not really a process.

Life IS a process. Saying that life is a "special state of the system"
and not a process sounds like vitalism again. You never said whether you
were a vitalist or not btw.

> If life could be
> characterised by an univocal process or mechanism, like Darwinian
> evolution, the problem of the concept of life would be solved.
>

If life could be characterised by an "univocal" *anything*... that would
result in an absolute definition, which a few sentences ago you said
wasn't necessary.

The problem isn't distinguishing "process" and "special state" (whatever
that is), it's that almost all definitions can't be absolute. Because
the concepts in question are a cluster of characteristics, which cluster
in a distinct enough fashion to be noticeable but not in an absolute
way. So you always have things that match the concept perfectly (have
all of those characteristics; they're in the middle of the cluster),
things that don't match it at all (have none of the characteristics;
they're completely outside the cluster), and things for which it's hard
to tell, and whether we say they're in the cluster or not is a judgement
call (have some of the characteristics but not others; they're on the
edges of the cluster).

[Arkalen]

(2012/02/13 7:06), marc.t...@wanadoo.fr wrote:
> On 12 fév, 22:08, Arkalen<arka...@inbox.com> wrote:
>> (2012/02/13 5:40), marc.tess...@wanadoo.fr wrote:
>>> On 12 fév, 20:27, Arkalen<arka...@inbox.com> wrote:
>>>>> "So at what percentage point did Darwinian evolution suddenly start ?"
>>>>> I must specify that the ONLY difference between the two kinds of
>>>>> vesicles is the heritability of specific characteristics: actually
>>>>> these specific characteristics, which are not related to nucleic acids
>>>>> or amino-acids, are transmitted to the daughter vesicles WITHOUT ANY
>>>>> CHANGE: then 100% of the information is transmitted.
>>
>>>> In that case Darwinian evolution is impossible. I don't think perfect
>>>> replication is even possible especially as the number of generations
>>>> increases, there must be a thermodynamics thing at work there. But if it
>>>> were, perfect replicants would never evolve.
>>
>>>>> Indeed, within such a model, there are possibilities for a KIND of
>>>>> mutations (which is not described in the article because I found it
>>>>> later on): when such a mutation occurrs the change is weak but
>>>>> significant in term of what can be called a phenotypic change, i.e. a
>>>>> possible occurrence of a NEW property.
>>
>>>> So... there IS change.
>>
>>>> And how do you go from non-replicating vesicles to near-perfectly
>>>> replicating vesicles ? I notice you said the ONLY difference between the
>>>> two kinds of vesicles (by which I assume you mean current experimental
>>>> vesicles, and your theoretical vesicles) is that the latter reproduce
>>>> with perfect heritability. But that... is not a small difference !
>>>> Nothing in the Universe replicates near-perfectly the way life does, and
>>>> life needs a buttload of complex machinery to achieve that. Do those
>>>> reproducing vesicles have specific characteristics that make them
>>>> reproduce the way their current experimental comrades don't ?
>>
>>>> It reminds me a bit of when I was a kid and I wondered why we had blood
>>>> instead of just water that contained all the stuff necessary to serve
>>>> whatever purposes blood served. Is it possible that something that's
>>>> just like the current experimental vesicles, with only the differences
>>>> necessary to make it replicate... would be a proto-cell ?
>>
>>> "In that case Darwinian evolution is impossible."
>>> Actually I think Darwinian evolution is possible: there is no absolute
>>> requirement of a kind of mutations (i.e. changes) for natural
>>> selection operating. If the model allows the emergence of several
>>> distinct lineages of vesicles then natural selection can operate on
>>> these lineages.
>>
>> Of course natural selection doesn't require mutations. Thing is, without
>> mutation there are no distinct lineages. Or if you're thinking of
>> distinct lineages that arose independently (not from a common ancestor),
>> those lineages *don't change*. Once something is culled by natural
>> selection it's gone, and the remaining lineages don't diversify to
>> compensate for the loss in diversity. And in fact, given at generation
>> zero the individuals aren't very-well adapted to the environment at all,
>> given enough time every single one of those unchanging lineages will be
>> wiped out and that's all she wrote.
>>
>> Basically what you have is evolution over one generation only. And
>> that's no evolution at all.
>>
>>> Of course, if a kind of mutation is possible then the
>>> number of distinct lineages would be much higher, during a period of
>>> time much shorter. Then Darwinian evolution would be much faster and
>>> much more efficient.
>>
>> I am baffled as to how Darwinian evolution could happen at all without
>> mutation. Maybe you could explain. And without mutation, how does your
>> number of "distinct lineages" go higher than one ? If they all arise
>> independently it's not evolution; there's no progression.
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>> "So... there IS change."
>>> At the beginning I didn't realise that the model had the capacity for
>>> a a kind of mutations but, later on, I found out it actually had it.
>>
>>> "And how do you go from non-replicating vesicles to near-perfectly
>>> replicating vesicles ?"
>>> - The vesicles reproduce by simple division.
>>> - However the lipid composition of their membrane is not stable: this
>>> composition is fully dependent on the nutriments provided by the
>>> environement.
>>> - Then vesicles do not self-replicate.
>>> - Only some specific characteristics replicate and are hereditary:
>>> specific membrane sites and specific molecules. Each membrane site/
>>> molecule couple forms a mutually catalytic process which is the most
>>> simple hypercycle you can imagine.
>>> - These site/molecule couples represent the hereditary information.
>>
>> And how much simpler are these site/molecule couples than ribosomes/RNA?
>> And if they're as simple as I can imagine, how come no abiogenesis lab
>> has come upon them yet ?
>>
>> Besides I'm not seeing the difference between those vesicles and any
>> other hypothesized kind of proto-cell, or what the difference of your
>> approach is in practice. Lots of people are looking at precursors for
>> life that don't use DNA or even RNA, and they don't worry about whether
>> they're looking at the origin of "life" or "Darwinian evolution".
>
> "I am baffled as to how Darwinian evolution could happen at all
> without mutation. Maybe you could explain. And without mutation, how
> does your number of "distinct lineages" go higher than one ? If they
> all arise independently it's not evolution; there's no progression."
> You are right:" If they all arise independently it's not evolution;
> there's no progression".
> Actually several possibilities of relationships between the lineages
> and/or between the membrane site/molecule couples are allowed by the
> model:
> - first there can be fusions of two vesicles: then the combined
> results are vesicles with both types of membrane site/molecule
> couples;
> - second the sites can migrate onto the inner part of the membrane
> with a possible linkage between two sites, leading to the formation of
> a more complex site which can favor the polymerisation of simple
> molecules, then multiply the possibilities for new compounds with new
> properties, particularly if the simple molecule is an AMINO-ACID!
> - third a site doesn't catalyse the synthesis of ONE molecule actually
> but of A CLASS of molecules: then numerous molecules with different
> properties are provided.

Those mechanisms don't sound as if they'd be conducive to the emergence
of lineages at all. More like a tangled bush. Which isn't a problem, it
makes a lot more sense to me that proto-life would have consisted of a
tangled web of relationships instead of the straightforward
ancestor-descendant relationships we see in animal species today. But
I'm not sure what it does to your contention that those vesicles would
herald a sharp division between "lack of Darwinian evolution" and
"Darwinian evolution as we know it".

>
> "And how much simpler are these site/molecule couples than ribosomes/
> RNA?"
> I don't think that the synthesis of ribosomes/RNA is simple without
> any catalysts, particularly because of the problem of the required
> enantioselectivity.

I wasn't suggesting the ribosome/RNA couple was simple. I was suggesting
I haven't seen evidence that your system could work while remaining as
simple as you seem to think it is.

> Moreover, in the conditions required for the emergence of open far-
> from-equilibrium self-sustained systems, that can maintain themselves
> far-from-equilibrium because they are able to exchange energy, matter,
> and information with the external environment, such as hydrothermal
> vents (e.g. the serpentinite-hosted Lost City Hydrothermal Field), the
> high temperature is fully deleterious for ribosomes/RNA.
>
> "And if they're as simple as I can imagine, how come no abiogenesis
> lab has come upon them yet ?"
> First nobody until now has tested such an hypothesis.
> Second the emergence of membrane site/molecule couples are not trivial
> occurrences.
>
> "Lots of people are looking at precursors for 'life' that don't use
> DNA or even RNA, and they don't worry about whether they're looking at
> the origin of 'life' or 'Darwinian evolution'."
> Not a lot. Labs working on the ribosomes/RNA approach are the majority
> because they want to reproduce the 'life' as we know it.
> The other labs have a major problem when working outside the ribosomes/
> RNA approach: the problem of the emergence of distinct lineages. In
> addition these labs want to reproduce the metabolism as we know it.
>

[John S. Wilkins]

Err... really? You have to ask? Okay, here's one:

"A fish is an invertebrate that flies"

[John S. Wilkins]

Some of that is rubbish (the Wolfe-Simon piece for example) and some is
speculative, and some are philosophy texts, which is why I didn't cite
them, but nevertheless you have just undercut your own statement. The
Miller-Urey experiment showed that some amino acids could be synthesised
without life. But Fox's vesicles show that reproducing objects can
spontaneously form and divide. I think that is more groundbreaking than
Miller-Urey.

[marc.t...@wanadoo.fr]

Sorry but it is possible to write "phenomenons". I find it more
popular than "phenomena".
Well, I do not understand your deduction.

"Life IS a process. Saying that life is a 'special state of the
system'
and not a process sounds like vitalism again. You never said whether
you
were a vitalist or not btw.

I think believing that the concept of life is scientifically sound is
'vitalism'!

"The problem isn't distinguishing "process" and "special
state" (whatever
that is), it's that almost all definitions can't be absolute."

I disagree and I would like to illustrate my view by an example.
Before the discover of Darwinian evolution theory the categorisation
of the species, groups, families etc. was just descriptive and
somewhat arbitrary = 'definitions'). Since Darwinian evolution theory
these catgorisations are now scientifically based on phylogeny which
is deducted from the mechanism of Darwinian evolution.

[Garamond Lethe]

On Tue, 14 Feb 2012 19:22:24 +1100, John S. Wilkins wrote:

> Bill <broger...@gmail.com> wrote:
>
>> On Feb 14, 4:54 am, j...@wilkins.id.au (John S. Wilkins) wrote:
>>
>>
>> > Definitions are correct or incorrect, precise or vague. But
>> > distinctions made about the natural world are accurate or not, true
>> > or false. If I say something like "All mammals have hair", this is
>> > not a definition, but it is a distinction that can easily be
>> > falsified by finding one that doesn't (a cetacean, for instance).
>>
>> How can a definition be incorrect?
>>
>> <snip>
>
> Err... really? You have to ask? Okay, here's one:
>
> "A fish is an invertebrate that flies"

Flying invertebrates are the best fish.

[Arkalen]

I've seen "phenomena" used as a singular a lot more than I've seen
"phenomenons" used as a plural. Certainly google gives an order of
magnitude or two more results for "phenomena" than for "phenomenons"
(although neither get as much as "phenomenon"). I can't dispute what you
find more popular in your experience, but your experience isn't
universal and in this case I don't think it's backed by the data.

(and looking at the results in details is even more striking - the first
results for "phenomenons" for me are "Welcome to Phenomenon", some kind
of site about "the unexplained and extraordinary" that doesn't even use
the word "phenomenons", a rather strange definition from
thefreedictionary.com (it gives "phenomenons" as a secondary definition
of "phenomenon" that says pl in front but the definitions associated are
in the singular), "10 Bizarre phenomena", the wikipedia page for
"phenomenon" which says "plural phenomena", the Wikipedia page for a
band called "The Phenomenons", the Merriam-Webster definition of
"phenomenon" which also says the plural is "phenomena"... and a
photography website that actually uses "phenomenons", which is the first
one to use the word the way you mean.)

> Well, I do not understand your deduction.

You said that understanding the processes and mechanisms at work was
better than defining things.

>
> "Life IS a process. Saying that life is a 'special state of the
> system'
> and not a process sounds like vitalism again. You never said whether
> you
> were a vitalist or not btw.
> I think believing that the concept of life is scientifically sound is
> 'vitalism'!

What ?
Then the whole field of biology, which studies life scientifically and
considers "vitalism" to be debunked, disagrees with you.

"vitalism" isn't an epithet, it's an actual point of view on the nature
of life. And that point of view isn't accurately described by "the
concept of life is scientifically sound".

I can actually on reflection see a reading of what you said that doesn't
imply vitalism. But using phrases like "special state of the system"
don't really help; it makes it sound as if the only difference between a
live organism and a dead one is that the former has the attribute of "life".

Anyway, this isn't about life. What you are saying applies to all
definitions in science. If the concept of "life" isn't scientifically
sound, how is the concept of [any member of the list John Wilkins gave
way back when] scientifically sound ?

>
> "The problem isn't distinguishing "process" and "special
> state" (whatever
> that is), it's that almost all definitions can't be absolute."
> I disagree and I would like to illustrate my view by an example.
> Before the discover of Darwinian evolution theory the categorisation
> of the species, groups, families etc. was just descriptive and
> somewhat arbitrary = 'definitions'). Since Darwinian evolution theory
> these catgorisations are now scientifically based on phylogeny which
> is deducted from the mechanism of Darwinian evolution.
>

... and they're still somewhat arbitrary. Which theropods are "birds"
and which are "non-avian theropods" ?

Before evolution species were categorised based on their apparent
characteristics. Now they're based on their evolutionary relationships,
which can be inferred from their apparent and less-apparent characteristics.

What changed was the basis for the definitions, not the fact that
they're arbitrary to some degree.

I can see a context where definitions are discovered to be wholly
arbitrary - in other words, more discoveries make it turn out that what
was thought to be a cluster of characteristics actually isn't that much
of a cluster at all. You could say that happened with classification
rankings; it used to be thought you could define "orders" and "classes"
and so on and that these distinctions were meaningful. Now we know that
such rankings don't have a basis in reality, depend on what we perceive
to be magnitudes of differences, and thus are almost completely arbitrary.

This is absolutely not the case with life. It might turn out to be in a
future Star Trek universe where we discover an incredible variety of
ways matter can organise itself, until what we consider "life" isn't its
own cluster anymore but just an ad-hoc collection of characteristics
that only made sense as their own thing in our limited Earth-based
understanding.

But this hasn't happened yet. As of now there is a clear divide between
things that are unambiguously alive and things that unambiguously
aren't, and the fuzzy borders are fairly small.

But anyway this is making less and less sense in the context of what
you've been saying. If the concept of "life" isn't scientifically sound,
why would you think defining it is at all an issue for abiogenesis
research ?

[Ymir]

In article <1kfgylt.3n54srxz4i92N%jo...@wilkins.id.au>,

jo...@wilkins.id.au (John S. Wilkins) wrote:

> Bill <broger...@gmail.com> wrote:
>
> > On Feb 14, 4:54 am, j...@wilkins.id.au (John S. Wilkins) wrote:
> >
> > >
> > > Definitions are correct or incorrect, precise or vague. But distinctions
> > > made about the natural world are accurate or not, true or false. If I
> > > say something like "All mammals have hair", this is not a definition,
> > > but it is a distinction that can easily be falsified by finding one that
> > > doesn't (a cetacean, for instance).
> >
> > How can a definition be incorrect?
> >
> > <snip>
>
> Err... really? You have to ask? Okay, here's one:
>
> "A fish is an invertebrate that flies"

I wouldn't call that an incorrect definition so much as a private one.
But not a very useful one since the silverfish (the type specimen for
fish) lacks wings. The starfish is, however, surprisingly aerodynamic.

André

[marc.t...@wanadoo.fr]

> research ?- Masquer le texte des messages précédents -

>
> - Afficher le texte des messages précédents -

First have you received my proposal about the illustration of a one
cycle reproduction?

"What changed was the basis for the definitions, not the fact that
they're arbitrary to some degree."

Again I disagree: the Darwinian evolution PROCESS is a much better
rational for the categorisation than anything else. It is no more a
problem of definitions.

"If the concept of "life" isn't scientifically sound,
why would you think defining it is at all an issue for abiogenesis
research ?"

'Abiogenesis' means a genesis before 'biology' appears (which is for
me the same as to say "before 'life' appears").
That is the issue.
That is why I suggest "the origin of Darwinian evolution research".

[Arkalen]

Haven't looked at that email box in awhile; I'll get back to you on that.

>
> "What changed was the basis for the definitions, not the fact that
> they're arbitrary to some degree."
> Again I disagree: the Darwinian evolution PROCESS is a much better
> rational for the categorisation than anything else. It is no more a
> problem of definitions.

Putting "process" in all-caps won't make it any more of a meaningful
distinction in this context. Life is a process too. Metabolism is a
process. Reproduction is a process. Looking at the origin of any of
those is equivalent to looking at the origin of life.

>
> "If the concept of "life" isn't scientifically sound,
> why would you think defining it is at all an issue for abiogenesis
> research ?"
> 'Abiogenesis' means a genesis before 'biology' appears (which is for
> me the same as to say "before 'life' appears").
> That is the issue.

Oh, you're doing argument by definition by decomposition too now ? It is
not necessary to have a perfect definition of "life" to understand how
life arose from non-life. It is perfectly possible to investigate that
question by applying the word "life" to things that are unambiguously
alive (modern cells), "non-life" to things that unambiguously aren't
(scattered organic molecules) and call all the intermediate steps
"proto-life".

It is even perfectly possible to do such an investigation without
slapping labels on those intermediate steps at all.

> That is why I suggest "the origin of Darwinian evolution research".
>

When looking at the origin of life on Earth it comes down to exactly the
same thing. Fuzziness at the intermediate steps included.