Revised Tautology FAQ - Thread-3
Friar Broccoli
What I have done is present a new structure for dealing with the
definition of a tautology, which I am pretty happy with, but I ran out
of time and the energy needed to integrate the new conclusions into
the balance of the text - which I will try to do next weekend.
One issue in the remainder of the text which is of particular
concern to me is John's original phrases:
"Darwinian theory rules out quite a lot. It rules out the existence
of inefficient organisms when more efficient organisms are about."
Although I initially defended this phrase against Burkhard, I have
now changed my mind. Consider for example:
- the Brown-throated Sloth (Bradypus variegatus) and
- the Spider monkeys of the genus Ateles
which have essentially the same range. Presumably the sloth
is more efficient than the spider monkey because it can convert
vegetable matter using the least energy. So why are there still
Spider monkeys? Obviously this argument is ridiculous but, I
believe it makes Burkhard's point that "efficient" doesn't have a
clear enough meaning to be left in the FAQ.
On the other hand, the phrase looks nice, so a defense of it or
a suggested replacement would be appreciated.
Here is my new effort:
The reader may want to jump to the marker which reads:
"---[[MOST new changes begin here]]---"
___________________________________________________________
Summary: The claim that evolutionary theory is unscientific or
unfalsifiable because it is a tautology rests on a
misrepresentation of, and focus on, the expression "Survival of
the Fittest" as well as a misunderstanding of the properties of
a tautology.
Darwin unwittingly created the tautology problem when, in the
fifth edition of his "On the Origin of Species," he changed the
title of the fourth chapter from "NATURAL SELECTION" to "NATURAL
SELECTION; OR THE SURVIVAL OF THE FITTEST." He wrote that he
did this because "Several writers have misapprehended or
objected to the term Natural Selection" on the basis that nature
can't "select" in the way that man can "select".
Unfortunately, some people now focus on the phrase "the survival
of the fittest" arguing that because it is a tautology, natural
selection and hence all of the theory of evolution is a fraud.
However, the words "survival of the fittest" do not by
themselves define evolution, which includes other processes such
as Mutation, Genetic Drift, and so on.. Rather, "survival of
the fittest" is more like a label, focusing attention on a key
idea in the natural selection process. Here, note that for
Darwin "The Survival Of The Fittest" was a synonym for, or
subset of, "Natural Selection" yet no one argues that "Natural
Selection" is a tautology.
A simple version of the so-called 'tautology argument' is this:
- Through the process of natural selection, the 'fittest' survive.
- Who are 'fittest'? The ones who survive.
- Thus natural selection merely asserts that those who
survive survive, a tautology. It just says the same thing twice.
- As a tautology, it cannot be tested because it cannot be
false. Hence, natural selection and thus the theory of
evolution are not scientific.
---[[MOST new changes begin here]]---
Before dealing with these assertions, we must first ask:
What is a tautology?
According to the Oxford English Dictionary - Its first citation
is from 1579: "It is a foolish tautologie, for you sayed the
same immediately before."
According to the Online Dictionary of Language Terminology
The word derives from the Late Latin tautologia, representation
of the same thing. It ultimately derives from the Greek tauto,
the same + logos, saying.
And it is there defined as "Repeating what has already been
said."
Thus it seems to have begun as meaning: being redundant by saying
the same thing twice. That seems harmless enough, but this
usage has been subtly expanded.
Consider some commonly sited examples like "black crow", "free
gift" or "new innovation". All these cases are considered to be
tautologies because an adjective (like black) desribes one of
the necessary properties of the subject (here crow). Thus we
have moved from saying that a tautology is a repetion of the
"same thing" to repeting the the "thing" and one of its
necessary properties.
We also see examples of tautologies using a form of equivalence
as in "All husbands are married men." or "All crows are black"
In the first example we see that the equivalence is the same
idea expressed with different words and is actually a
definition. In the second case the equivalence is between a
thing and one of its defining properties.
During the late middle ages it was fashionable among
philosophers to use tautologies similar to "God is a being which
has every perfection." and "A thing cannot be perfect if it does
not exist." to construct ontological proofs of God's existence.
This sort of thing annoyed some of the late enlightenment
philososphers notably Kant and Hume because the same forms
permitted nonsense like: "Man is the only rational animal" and
"Sometimes dogs are rational" therefore "sometimes dogs are
men."
Due to the analysis of the ontological arguments it became clear
that it is impossible to derive any certain conclusions about
the real world from proposition that derive their truth from
purely symantic principles. The semantic universe and the real
universe are separate categories.
Finally, in the early part of the nineteen hundreds tautologies
were incorporated into formal logic using forms like "p=p" and
"p or not p" which could be formally evaluated with truth
tables. Tautologies here might be described as statements that
cannot be denied without contradiction.
So from the historical context we can derive three properties of
tautologies:
1 repetition of meaning, using other words or symbols to
effectively say the same thing twice.
2 true by the meanings of words, true by the use of syntactical
elements
3 exist independently of observations from the real world
However, when taken together these three definitions appear to
creat a contradiction in some cases. Consider the tautologies:
1 married husband
2 black crow
3 white swan
If we did a survey and found that 1% of husbands were not
married we would just eliminate them from the result because
they don't meet the definition of "husband". If we did a survey
of crows and found a few that were not black, we might mutter a
bit about albinos and write a footnote about the exceptions.
Swans are a bigger problem because they were formerly defined as
white, until a population of black swans was found in Australia.
Thus, there can be little dispute that "husbands are married" is
true from the meanings of the words alone, independently of
observation. However this is clearly not the case for "swans are
white" which can be falsified by comparing the content of the
statement with the real world objects to which they refer. This
then raises the question: Is "crows are black" a tautology?
This then leads back to our question: "What is a tautology?" Well
sorry, but I don't know, however if we assume that both "black
crows" and "married husbands" are tautologies, then they are
clearly of different types. Philosophers classify tautologies
and propositions in general into frighteningly large arrays of
often incompatible categories, but for our purposes here, we will
deal only with propositions or tautologies that are:
necessary: those whose meanings are necessary only from the words,
including "all husbands are married".
contingent: those whose meanings are contingent on an
examination of associated reality including "all
crows are black".
Armed with this information we can now go back and ask: Is
"Survival of the Fittest" a tautology, and if so, of what type?
---[[MOST new changes end here]]---
Well, in population genetics there is a formal variable called
fitness which is measured by the proportion of a trait that
survives into the next generation. The simplest form of the
equation looks like this:
W_abs_ = N_after_/N_before_
where:
W_abs_ is absolute fitness
N_before_ is the Number of individuals with some genotype
in a first generation (before selection)
N_after_ is the Number of individuals with an alternative genotype
in the following generation (after selection)
So quite clearly just as 'bachelor' is defined as 'an unmarried
man' 'fitness' is here defined as the 'survival' rate in the
following generation. Thus, it is clear that the expression
"Survival of the Fittest" is a tautology.
However, note that:
W_abs_ = N_after_/N_before_
is also a tautology since it is just another way of saying
"Survival of the Fittest". Indeed since as we saw above the
equivalence of the same idea expressed in a different form is a
tautology, all mathematical expressions containing a single
equal sign between two sets of equivalent expressions are
similarly tautologies.
This includes
Newton's F=ma and Einstein's E=MC^2.
F=ma is of particular interest here because although it is a
tautology, it has in fact been falsified. That is, it is not
true in relativistic frameworks, a fact which has been
observationally verified. Similarly, "white swan" was once
thought to be a tautology, up until they found black ones in
Australia. Thus, being a tautology, does not immunize a
statement from being falsified by observation.
And indeed to some extent, like Newton's laws of motion,
"survival of the fittest" has itself been falsified by science.
When Darwin wrote, he knew of no criteria for survival other
than fitness (assuming that sexual selection is included as part
of fitness), but since his passing the study of genetics, which
he knew nothing about, has shown that genetic drift is a majour
determinant of inherited characteristics. Essentially, random
mutations which may code for characteristics having little or no
'fitness' value become fixed in populations essentially by
chance. So arguable the tautology under discussion here should
read "survival of the fittest and luckiest".
So even if it were the case that 'Survival of the Fittest' was a
complete description of the theory of evolution, asserting that
it is a tautology does not make it unfalsifiable.
Consider also that there is widespread agreement that, at least,
microevolution is falsifiable by testing. Phillip Johnson, no
friend of Darwinism, writes that "...everyone agrees that
microevolution occurs, including creationists" (Darwin on Trial,
page 68). People who try to breed faster horses or smaller dogs
(e.g., to create cute, tiny pets for city dwellers) or to breed
more productive strains of wheat or citrate-eating bacteria are
all, in effect, testing evolution using artificial selection.
If they consistently failed in these efforts, evolution would
thereby be falsified. (Examples of natural selection in nature
include the peppered moth and Nylon-eating bacteria. (For
evidence that macroevolution is testable, see 29 Evidences for
Macroevolution.))
Another deeper problem with the tautology argument is that
although 'fitness' (the label) is conceptually identical with
increased survival and replication, in the real world fitness
refers to a set of detailed characteristics that develop and are
maintained in response to specific environmental conditions.
Together these environments and the characteristics that evolve
in response to them form a causal account which is anything but
tautological. For example:
- Some non-poisonous butterflies develop bright coloration that
mimics the form of poisonous butterflies, because birds learn
from the poisonous variety to avoid that pattern.
- The peppered moth turned black and then returned to a peppery
coloration as its environment changed making one pattern and
then another harder for predators to detect.
- Sloths slowed down almost to a stop, because a slow moving
animal with blue-green algae growing in its hair is very
difficult for predators to see.
There is nothing tautological about:
- survival of the most colorful or
- survival of the slowest.
and should that be:
- survival of the pepperiest or
- survival of the blackest?
Without a causal account we cannot say.
Karl Popper [1976: sect. 37] also had doubts about whether
"Darwinism" was a testable scientific theory. According to
Popper, any situation where species exist is compatible with
Darwinian explanation, because if those species were not
adapted, they would not exist. That is, Popper says, we define
adaptation as that which is sufficient for existence in a given
environment. Therefore, since nothing is ruled out, the theory
has no explanatory power, for everything is ruled in.
This is not true, as a number of critics of Popper have observed
since (e.g., Stamos [1996] [note 1]). Darwinian theory rules out
quite a lot. It rules out the existence of inefficient organisms
when more efficient organisms are about. It rules out change
that is theoretically impossible (according to the laws of
genetics, ontogeny, and molecular biology) to achieve in gradual
and adaptive steps (see Dawkins [1996]). It rules out new
species being established without ancestral species.
All of these hypotheses are more or less testable, and conform
to the standards of science. The answer to this version of the
argument is the same as to the simplistic version - adaptation
is not just defined in terms of what survives. There needs to
be a causal account available to make sense of adaptation (which
is why mimicry in butterflies was such a focal debate in the
teens and twenties). Adaptation is a functional notion, not a
logical or semantic a priori definition, despite what Popper
thought.
Thus, the tautological attack on evolution fails because:
- "Survival of the Fittest" is not a complete description of
evolution. It misses, among other things, genetic drift.
- 'Fitness' in the context of a casual account is not
tautologically equivalent to survival.
- Tautologies are unfalsifiable only with respect to their
symbolic character.
- Tautologies like F=ma and 'white swan' are falsifiable with
respect to the real world realities to which they refer.
- The creationist tautological attack is on one label "survival
of the fittest" used to refer to evolution, not evolution itself.
John S. Wilkins
> The following text doesn't properly fit together.
> What I have done is present a new structure for dealing with the
> definition of a tautology, which I am pretty happy with, but I ran out
> of time and the energy needed to integrate the new conclusions into
> the balance of the text - which I will try to do next weekend.
>
> One issue in the remainder of the text which is of particular
> concern to me is John's original phrases:
>
> "Darwinian theory rules out quite a lot. It rules out the existence
> of inefficient organisms when more efficient organisms are about."
>
> Although I initially defended this phrase against Burkhard, I have
> now changed my mind. Consider for example:
>
> - the Brown-throated Sloth (Bradypus variegatus) and
> - the Spider monkeys of the genus Ateles
>
> which have essentially the same range. Presumably the sloth
> is more efficient than the spider monkey because it can convert
> vegetable matter using the least energy. So why are there still
> Spider monkeys? Obviously this argument is ridiculous but, I
> believe it makes Burkhard's point that "efficient" doesn't have a
> clear enough meaning to be left in the FAQ.
>
> On the other hand, the phrase looks nice, so a defense of it or
> a suggested replacement would be appreciated.
>
I think that phrase should be dropped altogether. It fails to address
the tautology argument and is, in that sense, something of a tautology
itself. And actually if you want to make a thermodynamic account of
fitness - something I am not opposed to - then you have to talk about
capturing and using for the maximum period of free energy. In that sense
I think you might be able to argue that entire ecosystems have a
thermodynamic fitness.
While I'm about it, note that I am doing aseries on the tautology
problem on my blog. Here are the posts to date:
http://evolvingthoughts.net/2009/08/20/the-tautology-problem/
http://evolvingthoughts.net/2009/08/21/tautology-1a-corrections/
http://evolvingthoughts.net/2009/08/22/tautology-1b-butler/
http://evolvingthoughts.net/2009/08/23/tautology-2-the-problem-arises/
The next posts will be:
3: The problem spreads
4. What is a tautology? [What the problems are with tautologies]
5. A proposed resolution
My resolution will be that natural selection is not an explanation of
anything - it's a sketch of how an actual explanation might go. It is an
explanatory schema, in other words. There will be a discussion of how
formal models apply and explain.
--
John S. Wilkins, Philosophy, University of Sydney
http://evolvingthoughts.net
But al be that he was a philosophre,
Yet hadde he but litel gold in cofre
David Hare-Scott
> The following text doesn't properly fit together.
> What I have done is present a new structure for dealing with the
> definition of a tautology, which I am pretty happy with, but I ran out
> of time and the energy needed to integrate the new conclusions into
> the balance of the text - which I will try to do next weekend.
>
> One issue in the remainder of the text which is of particular
> concern to me is John's original phrases:
>
> "Darwinian theory rules out quite a lot. It rules out the existence
> of inefficient organisms when more efficient organisms are about."
>
Is this the same as saying that in the long term two species cannot occupy
the same niche? Is "single population occupant of a niche" tautologous with
"species"? If not using this language presents a testable proposition that
avoids the vagueness of "efficiency".
Has there ever been a case where two species seemed to occupy the same niche
long term and this resulted in them being declared separate species? If so
are we caught in circularity?
> Although I initially defended this phrase against Burkhard, I have
> now changed my mind. Consider for example:
>
> - the Brown-throated Sloth (Bradypus variegatus) and
> - the Spider monkeys of the genus Ateles
>
> which have essentially the same range. Presumably the sloth
> is more efficient than the spider monkey because it can convert
> vegetable matter using the least energy. So why are there still
> Spider monkeys? Obviously this argument is ridiculous but, I
> believe it makes Burkhard's point that "efficient" doesn't have a
> clear enough meaning to be left in the FAQ.
>
> On the other hand, the phrase looks nice, so a defense of it or
> a suggested replacement would be appreciated.
>
....snip essay ...
I thought this version much clearer. BTW it needs a spell check :-)
David
J.J. O'Shea
(in article <h6su4u$h91$1...@news.albasani.net>):
> Is this the same as saying that in the long term two species cannot occupy
> the same niche? Is "single population occupant of a niche" tautologous with
> "species"? If not using this language presents a testable proposition that
> avoids the vagueness of "efficiency".
>
> Has there ever been a case where two species seemed to occupy the same niche
> long term and this resulted in them being declared separate species? If so
> are we caught in circularity?
That depends on how you define 'niche'. Lions and tigers share the Large Cat
Niche in parts of Asia. A lot of sharks, in general, share the Large Marine
Predator Niche with a lot of dolphins in general, and great whites and orcas
share Hunters of Seals in particular. A whole bunch of baleen whales share
the Large Mobile Marine Filter Feeder with each other, and with whale sharks.
Here in Deepest Florida, the American Alligator and the American Crocodile
share the same Big Bad Heavily Armoured Reptile Niche. (They're really hard
to tell apart unless you know what you're looking for; for example, one of
the worst James Bond movies has a scene where 007 runs and jumps over a row
of 'gators... except that they're actually crocs. That scene is proof that
corcs are better actors than Roger Moore.) Pit vipers share the Hunter of
Small Rodents and Rabbits Niche with each other (and there are a lot of them)
and with foxes, wolves, bobcats, lynx, redtailed hawks, barn owls... there's
a _long_ list for that one.
Or maybe I'm unclear on 'niche' or on your position.
--
email to oshea dot j dot j at gmail dot com.
Ernest Major
<try.n...@but.see.sig> writes
>On Sun, 23 Aug 2009 21:27:15 -0400, David Hare-Scott wrote
>(in article <h6su4u$h91$1...@news.albasani.net>):
>
>> Is this the same as saying that in the long term two species cannot occupy
>> the same niche? Is "single population occupant of a niche" tautologous with
>> "species"? If not using this language presents a testable proposition that
>> avoids the vagueness of "efficiency".
>>
>> Has there ever been a case where two species seemed to occupy the same niche
>> long term and this resulted in them being declared separate species? If so
>> are we caught in circularity?
>
>That depends on how you define 'niche'. Lions and tigers share the Large Cat
>Niche in parts of Asia.
I'd drop cat from description of the niche. Try large ambush predator
niche. Tigers and lions have different habitats. Tigers are
jungle/forest animals. Lions are mostly savanna animals (the surviving
Indian population is in open woodland - Gir Forest). Tigers are
solitary. Lions are social.
> A lot of sharks, in general, share the Large Marine
>Predator Niche with a lot of dolphins in general, and great whites and orcas
>share Hunters of Seals in particular. A whole bunch of baleen whales share
>the Large Mobile Marine Filter Feeder with each other, and with whale sharks.
>Here in Deepest Florida, the American Alligator and the American Crocodile
>share the same Big Bad Heavily Armoured Reptile Niche. (They're really hard
>to tell apart unless you know what you're looking for; for example, one of
>the worst James Bond movies has a scene where 007 runs and jumps over a row
>of 'gators... except that they're actually crocs. That scene is proof that
>corcs are better actors than Roger Moore.) Pit vipers share the Hunter of
>Small Rodents and Rabbits Niche with each other (and there are a lot of them)
>and with foxes, wolves, bobcats, lynx, redtailed hawks, barn owls... there's
>a _long_ list for that one.
>
>Or maybe I'm unclear on 'niche' or on your position.
>
You're using niche where guild is more appropriate. Niches are sliced
more finely. Specialisation and frequency depending selection allow a
guild's life style to be sliced into several to many niches.
--
alias Ernest Major
Ernest Major
<9fa75424-f9e4-4ce1...@b15g2000yqd.googlegroups.com>,
Friar Broccoli <eli...@gmail.com> writes
I don't think that these are tautologies. Rather they are unsupported
axioms.
What you have given here is the result in an infinitely large
population, where stochastic effects are neglected. By applying it to a
finite population you have sharpened the tautology.
You've turned it into survival of the survivors. In population genetics
fitness refers to survival causally related to the trait. (See mentions
of propensity formulations of survival of the fittest which others have
already mentioned.)
I'm fairly sure that Darwin hadn't identified chance survival as a
source of evolutionary change (he may well have assumed that it averaged
out of the generations) but I wouldn't be confident that he was unaware
of chance components to survival.
--
alias Ernest Major
J.J. O'Shea
(in article <xlMoySCE$kkK...@meden.invalid>):
> You're using niche where guild is more appropriate. Niches are sliced
> more finely. Specialisation and frequency depending selection allow a
> guild's life style to be sliced into several to many niches.
Okay. I stand corrected.
Steven L.
> The following text doesn't properly fit together.
> What I have done is present a new structure for dealing with the
> definition of a tautology, which I am pretty happy with, but I ran out
> of time and the energy needed to integrate the new conclusions into
> the balance of the text - which I will try to do next weekend.
>
> One issue in the remainder of the text which is of particular
> concern to me is John's original phrases:
>
> "Darwinian theory rules out quite a lot. It rules out the existence
> of inefficient organisms when more efficient organisms are about."
What's wrong is the phrase "rules out." See below.
> Unfortunately, some people now focus on the phrase "the survival
> of the fittest" arguing that because it is a tautology, natural
> selection and hence all of the theory of evolution is a fraud.
Why do you keep saying "now"???
I complained about this once before. The tautology argument is ancient.
It probably goes all the way back to when Darwin published Origin of
Species. It's been resurrected again and again. Martin Gardner in
"Fads and Fallacies" (1956) called it "quaint."
Can you please amend this so it's clear that the tautology argument is
NOT a recent argument, but just dredged up from time to time? To imply
it's a recent argument suggests that creationists are discovering new
arguments against "Darwinism" all the time. They're not. They haven't
discovered a new argument in a century. And that's important.
> We also see examples of tautologies using a form of equivalence
> as in "All husbands are married men." or "All crows are black"
> In the first example we see that the equivalence is the same
> idea expressed with different words and is actually a
> definition. In the second case the equivalence is between a
> thing and one of its defining properties.
Here's a white crow for you:
http://www.birds.cornell.edu/crows/whitecrows.htm
Evidently "All crows are black" is now falsified by a couple of exceptions.
> Karl Popper [1976: sect. 37] also had doubts about whether
> "Darwinism" was a testable scientific theory. According to
> Popper, any situation where species exist is compatible with
> Darwinian explanation, because if those species were not
> adapted, they would not exist. That is, Popper says, we define
> adaptation as that which is sufficient for existence in a given
> environment. Therefore, since nothing is ruled out, the theory
> has no explanatory power, for everything is ruled in.
>
> This is not true, as a number of critics of Popper have observed
> since (e.g., Stamos [1996] [note 1]). Darwinian theory rules out
> quite a lot. It rules out the existence of inefficient organisms
> when more efficient organisms are about.
Darwinian theory doesn't "rule out" any inefficient species. It
*favors*, or perhaps just *biases*, efficient organisms toward having a
greater probability of survival (and hence passing on their genes to
their descendants). But even when it appears that the more efficient
organisms can dominate their less efficient competitors, s**t can
happen. Times change. And a new environmental situation makes the more
efficient organisms suddenly less efficient, and the bias starts working
the other way.
Indeed, if all inefficient organisms became extinct, that would make
evolution much harder. Reproduction is constantly supplying a vast
range of variations, most of which are *currently* inefficient. Some
may go extinct. But some may survive in isolated subpopulations,
surviving at the margins, barely hanging on, but awaiting changes to the
environment which would make them more efficiently suited.
--
Steven L.
Email: sdli...@earthlinkNOSPAM.net
Remove the NOSPAM before replying to me.
John S. Wilkins
> Friar Broccoli wrote:
> > The following text doesn't properly fit together.
> > What I have done is present a new structure for dealing with the
> > definition of a tautology, which I am pretty happy with, but I ran out
> > of time and the energy needed to integrate the new conclusions into
> > the balance of the text - which I will try to do next weekend.
> >
> > One issue in the remainder of the text which is of particular
> > concern to me is John's original phrases:
> >
> > "Darwinian theory rules out quite a lot. It rules out the existence
> > of inefficient organisms when more efficient organisms are about."
>
> What's wrong is the phrase "rules out." See below.
>
>
> > Unfortunately, some people now focus on the phrase "the survival
> > of the fittest" arguing that because it is a tautology, natural
> > selection and hence all of the theory of evolution is a fraud.
>
> Why do you keep saying "now"???
> I complained about this once before. The tautology argument is ancient.
The earliest version I have found is Samuel Butler's in 1879.
> It probably goes all the way back to when Darwin published Origin of
> Species. It's been resurrected again and again. Martin Gardner in
> "Fads and Fallacies" (1956) called it "quaint."
>
...
Friar Broccoli
.
> My resolution will be that natural selection is not an explanation of
> anything - it's a sketch of how an actual explanation might go. It is an
> explanatory schema, in other words. There will be a discussion of how
> formal models apply and explain.
I wonder if this isn't just unnecessarily complicating a simple issue.
Right now I think the Tautology argument collapses entirely
with two observations:
(1) that "Crows are black" and like expressions are not
tautologies if the meaning of tautology includes "true by
the meanings of words" and "exist independently of
observations from the real world". "Crows" doesn't imply black
because of "the meaning of words". "Black" is there because
there are independent objects out there that are always black.
(2) that Popper's assertion that "those that survive are the
fittest" and "those that survive are those that survive"
have the same meaning is obvious hogwash. Three legged
antelope are obviously less fit and don't survive. Yes
there are marginal cases where the meaning of fitness is not
easily discerned, but there are more than enough clear cases
that can be plugged into the fitness variable. Can a case
be made that the existence of marginal cases somehow negate
the clear cases? (This last is a serious question - Am I
missing something here?)
ivar
I have problems with this version. It's too long and too
complicated. I fear that many of the intended readers will abandon it
part way through because they feel confused and because they have
begun to suspect that it will never be convincing. Also, the idea of
a "contingent" tautology is a problem. Tautologies are always true,
they are never false.
Here is a suggested alternative that is shorter and simpler:
-----------------------------------------------------------------------------------------------------
Ann Coulter, a vocal opponent of evolution, describes the so-called
'tautology argument' this way:
"Through the process of natural selection, the 'fittest' survive.
Who are the 'fittest'? The ones who survive....
The beauty of having a scientific theory that's a tautology is
that it can't be disproved."
But her reasoning is naive and incomplete.
Natural selection separates organisms into winners and losers. Over
time, the offspring of the winners increase in numbers and the
offspring of the losers decrease in numbers. Darwin and some of his
supporters found it convenient to label the winners as the "fittest."
Coulter's last two sentences, in effect, define "fittest": the fittest
are the ones who survive. In other words, evolution is about the
survival of the fittest.
A definition is a kind of tautology. A tautology as the word is used
here is a statement that is always true. For example, the statement
that 'it is raining or it is not raining' is a tautology because it is
always true. A definition is similar in that the word or phrase that
is defined and the words that define that word or phrase are declared
to be identical in meaning. In our case, "the fittest" and "the ones
that survive" mean the same thing and, hence, the statement that "the
fittest are the ones who survive" is always true. (Another, older
definition of tautology is that a tautology is the unnecessary
repetition of meaning in a sentence, for example, "free gift." Gifts
are always free. However, this older definition is not important in
this discussion.)
The problem with Coulter's statements is that the question "Who are
the 'fittest'"? can be answered in more than one way. Coulter's
answer was to repeat the definition of fittest, which is a tautology.
It is always true and, therefore, cannot be tested. But there are
other answers that are not necessarily true and that, therefore, are
testable. Depending on the circumstances, fitness could mean high
running speed or resistance to disease or successful camouflage (e.g.,
insects that resemble twigs), and so on. The natural world is
complicated. Many hypotheses are possible and testing particular
hypotheses about fitness are not necessarily easy. But testing is
often possible and evolution is, therefore, not a tautology.
Testing is not limited to tests of whether a particular trait
contributes to fitness. One can also ask, for example, whether the
details of what constitutes fitness change over time and from place to
place. If the places are the middle of the Atlantic Ocean and the
middle of the Gobi Desert, then one doesn't need Darwin to know that
species will be very different in these two locations. One might also
expect that organisms would change over time as climate and even land
masses change and as competing species evolve. And, that is what is
observed in the fossil record.
Consider also that there is widespread agreement that, at least,
microevolution is falsifiable by testing. Phillip Johnson, no friend
of Darwinism, writes that "...everyone agrees that microevolution
occurs, including creationists" (Darwin on Trial, page 68). People
who try to breed faster horses or smaller dogs (e.g., to create cute,
tiny pets for city dwellers) or to breed more productive strains of
wheat or citrate-eating bacteria are all, in effect, testing evolution
using artificial selection. If they consistently failed in these
efforts, evolution would thereby be falsified. Examples of natural
selection in nature include the peppered moth and Nylon-eating
bacteria. For evidence that macroevolution is testable, see 29
Evidences for Macroevolution.
[The Popper paragraphs go here.]
The Coulter reference is:
Coulter, Ann: 2007. Godless, The Church of Liberalism, Three Rivers
Press, pages 212 & 213.
ivar
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Ann Coulter, a vocal opponent of evolution, describes the so-called
'tautology argument' this way:
"Through the process of natural selection, the 'fittest' survive.
Who are the 'fittest'? The ones who survive....
The beauty of having a scientific theory that's a tautology is
that it can't be disproved."
But her reasoning is naive and flawed
Natural selection separates organisms into winners and losers. Over
time, the offspring of the winners increase in numbers and the
offspring of the losers decrease in numbers. Darwin and some of his
supporters found it convenient to label the winners as the "fittest."
Coulter's second and third sentences, in effect, define "fittest": the
fittest are the ones who survive. In other words, evolution is about
the survival of the fittest.
What is a tautology? As Coulter uses the term, a tautology is a
statement that is always true. For example, the statement that
'either it is raining or it is not raining' is a tautology because it
is always true. A definition is a kind of tautology in that the word
or phrase that is defined and the words that define that word or
phrase are declared to be identical in meaning. In our case, "the
fittest" and "the ones who survive" mean the same thing and, hence,
the statement that "the fittest are the ones who survive" is always
true, i.e., a tautology. (Another, older definition of tautology is
that a tautology is the unnecessary repetition of meaning in a
sentence. An example is "free gift" (gifts are always free).
However, this older definition is not important in this discussion.
The creationists are not complaining that the evolutionists are
unnecessarily wordy.)
But Coulter is not merely saying that the definition of the fittest is
a tautology. She is asserting that the theory of evolution is a
tautology. Her justification for this is obscure but it is likely
that it is related to Darwin's declaration that 'natural selection'
and "the survival of the fittest" are alternative labels for the same
evolutionary process. In the fifth edition of his "On the Origin of
Species," Darwin changed the title of the fourth chapter from "NATURAL
SELECTION" to "NATURAL SELECTION; OR THE SURVIVAL OF THE FITTEST." He
wrote that he did this because "Several writers have misapprehended or
objected to the term Natural Selection" on the basis that nature can't
"select" in the way that man can "select." But there is a problem
with Coulter's interpretation of this. The phrase "the survival of
the fittest" is based on the definition of fittest, which is a
tautology. But when the phrase is used as the label for an
evolutionary process, it does not mean that that process is a
tautology. The issue is not whether the label is based on a tautology
but, rather, whether the labeled process is testable. Science is not
blocked because somebody defines something.
Actually, many different answers to Coulter's question "Who are the
'fittest'"? are possible. Depending on the circumstances, the fittest
could be those that run faster or those that better resist disease or
those that employ more effective camouflage (e.g., insects that
resemble twigs), and so on. These hypotheses can often be tested. The
testing is not necessarily easy. The natural world is complicated and
results can be obscured by irrelevant events. But testing is often
possible and the theory of evolution is, therefore, not a tautology.
John S. Wilkins
> Another draft:
Here is a useful summary on fitness in biology:
de Jong, G. 1994. The Fitness of Fitness Concepts and the Description of
Natural Selection. The Quarterly Review of Biology 69 (1):3-29.
Friar Broccoli
> Friar Broccoli wrote:
> > The following text doesn't properly fit together.
> > What I have done is present a new structure for dealing with the
> > definition of a tautology, which I am pretty happy with, but I ran out
> > of time and the energy needed to integrate the new conclusions into
> > the balance of the text - which I will try to do next weekend.
>
> > One issue in the remainder of the text which is of particular
> > concern to me is John's original phrases:
>
> > "Darwinian theory rules out quite a lot. It rules out the existence
> > of inefficient organisms when more efficient organisms are about."
>
> Is this the same as saying that in the long term two species cannot occupy
> the same niche? Is "single population occupant of a niche" tautologous with
> "species"? If not using this language presents a testable proposition that
> avoids the vagueness of "efficiency".
>
> Has there ever been a case where two species seemed to occupy the same niche
> long term and this resulted in them being declared separate species? If so
> are we caught in circularity?
Aside from the definitional problems discussed (in summary)
by JJ and Ernest there is, I think, a practical problem. Assuming
it is the case that 'two species cannot occupy the same niche' is
some sort of general rule we would never see any examples.
All the evidence (less efficient species) must necessarily have
gone extinct, leaving only the exceptions to the rule.
> > Although I initially defended this phrase against Burkhard, I have
> > now changed my mind. Consider for example:
>
> > - the Brown-throated Sloth (Bradypus variegatus) and
> > - the Spider monkeys of the genus Ateles
>
> > which have essentially the same range. Presumably the sloth
> > is more efficient than the spider monkey because it can convert
> > vegetable matter using the least energy. So why are there still
> > Spider monkeys? Obviously this argument is ridiculous but, I
> > believe it makes Burkhard's point that "efficient" doesn't have a
> > clear enough meaning to be left in the FAQ.
>
> > On the other hand, the phrase looks nice, so a defense of it or
> > a suggested replacement would be appreciated.
>
> ....snip essay ...
>
> I thought this version much clearer.
Thanks, I found this comment very encouraging.
> BTW it needs a spell check :-)
Next weekend when I do the rewrite.
J. J. Lodder
A typical example of circularity.
Suppose we see two species occupying the same niche.
(to all appearances)
Do we conclude that the ToE is falsified?
Of course not.
We conclude that there must be some subtle difference
in the way the two species survive that we don't understand yet.
(on to the next grant proposal)
They both survive, so they must be in different niches,
must't they?
Jan