Bears and Speciation
Vanman
In speaking with creationists it seems most I have met say initially that
they don't believe in evolution and then change their mind regarding
micro-evolution (which still makes them supporters of evolution btw). Of
course they deny macro-evolution as god made everything according to its
kind (a definition of which many seem to slither around conveniently).
Just as we do not see languages evolve (anyone discover evidence of
Norwegian or Apache existing somewhere between the middle east and where
these groups ended up?..lol) there is (as far as I know) no explicit
evidence of macro-evolution per se. Nevertheless I was thinking the other
day that there are around 8 species of bears. Now it is my undestanding that
the definition of a species is where two animals can create offspring.
NJevertheless can someone please confirm for me that a Grizzly and Polar
Bear cannot mate and create offspring? If that is the case to me that would
be pretty strong evidence of macro-evolution would it not?
Thanks.
Greg G.
No, it has been long known that polar bears and grizzlies can produce
offspring. The hybrids are called "pizzlies". They have been suspected
to occur in the wild. One wild specimen was given a DNA test that
showed the mother was a polar bear and the father was a grizzly.
http://en.wikipedia.org/wiki/Grizzly%E2%80%93polar_bear_hybrid
richardal...@googlemail.com
> Greetings all.
>
> In speaking with creationists it seems most I have met say initially that
> they don't believe in evolution and then change their mind regarding
> micro-evolution (which still makes them supporters of evolution btw). Of
> course they deny macro-evolution as god made everything according to its
> kind (a definition of which many seem to slither around conveniently).
>
> Just as we do not see languages evolve (anyone discover evidence of
> Norwegian or Apache existing somewhere between the middle east and where
> these groups ended up?..lol) there is (as far as I know) no explicit
> evidence of macro-evolution per se. Nevertheless I was thinking the other
> day that there are around 8 species of bears. Now it is my undestanding that
> the definition of a species is where two animals can create offspring.
Not really. Species boundaries can be rather fuzzy, and many pairs of
species can produce offspring. In many cases the offspring themselves
are viable - i.e. they can produce offspring.
> NJevertheless can someone please confirm for me that a Grizzly and Polar
> Bear cannot mate and create offspring? �If that is the case to me that would
> be pretty strong evidence of macro-evolution would it not?
>
> Thanks.
The genetic relationship between polar bear and brown bears (of which
grizzly bears are a subspecies) is complex.
http://www.polarbearsinternational.org/polar-bears-in-depth/evolution/
Polar bears arose more than once from brown bear ancestry.
RF
r norman
wrote:
The brown bears, themselves, are a troublesome group with some people
arguing for separate species and others for only subspecies rank of
the various types.
So you (Vanman) picked a particularly bad example to argue from.
chris thompson
>
> In speaking with creationists it seems most I have met say initially that
> they don't believe in evolution and then change their mind regarding
> micro-evolution (which still makes them supporters of evolution btw). Of
> course they deny macro-evolution as god made everything according to its
> kind (a definition of which many seem to slither around conveniently).
>
> Just as we do not see languages evolve (anyone discover evidence of
> Norwegian or Apache existing somewhere between the middle east and where
> these groups ended up?..lol) there is (as far as I know) no explicit
> evidence of macro-evolution per se.
This is untrue. There is plenty of evidence for macroevolution.
Speciation has been observed numerous time, especially in plants. In
addition, the genetic evidence is rather overwhelming. Look at the
presence of endogenous retroviruses in human and chimp DNA for an
example.
Chris
TomS
<8d742987-6c1d-4869...@g26g2000yqe.googlegroups.com>, chris
thompson stated..."
>
>On Dec 27, 1:14�pm, "Vanman" <Vancan...@shaw.ca> wrote:
>> Greetings all.
>>
>> In speaking with creationists it seems most I have met say initially that
>> they don't believe in evolution and then change their mind regarding
>> micro-evolution (which still makes them supporters of evolution btw). Of
>> course they deny macro-evolution as god made everything according to its
>> kind (a definition of which many seem to slither around conveniently).
>>
>> Just as we do not see languages evolve (anyone discover evidence of
>> Norwegian or Apache existing somewhere between the middle east and where
>> these groups ended up?..lol) there is (as far as I know) no explicit
>> evidence of macro-evolution per se.
>
>This is untrue. There is plenty of evidence for macroevolution.
>Speciation has been observed numerous time, especially in plants. In
>addition, the genetic evidence is rather overwhelming. Look at the
>presence of endogenous retroviruses in human and chimp DNA for an
>example.
If "macroevolution" is defined as "evolution which results in a
new species", then macroevolution has been directly observed. There
have been a few cases in which a new genus has been observed to
happen (I'm thinking of Triticale), but then there is no reason to
think that genus - or any taxonomic category larger than species -
has any objective reality.
I think of the analogy with achieving supersonic flight. Once the
"sound barrier" has been "broken", then there is no reason to think
that there is an "X barrier" to very fast flight. The burden of
proof shifts to the person claiming the existence of such a barrier.
Once the "species barrier" to evolution has been broken, then what
barrier can anyone think of? I'd note that the "baraminologists"
just borrow a definition of species. They have nothing to offer.
(And this means that they have created a problem for themselves:
If a "kind" is defined as such-and-such, then how is a species
defined? I don't think the baraminologists can get away with
saying that species are not real.)
Of course, if "macroevolution" is given a "moving the goalposts"
definition, something like "evolution which has not been directly
observed", then no, it hasn't been directly observed. But then,
the concept of "having been directly observed" is open to having its
objective reality questioned. It certainly doesn't seem to be very
interesting in any other science: Try to figure out whether atoms
have been directly observed. Yes, I know that there are photographs
of single atoms, but those photographs have been taken using
instruments whose operations can be understood only by assuming the
soundness of physics which is relies on the reality of atoms.
So yes, there is plenty of old-fashioned, well established
evidence for evolution at very large scales, the kind of evidence
which is well within the realm of evidence which is regularly used
by every other area of science. The endogenous retroviruses just
being a recent new line of evidence which is very interesting.
--
---Tom S.
the failure to nail currant jelly to a wall is not due to the nail; it is due to
the currant jelly.
Theodore Roosevelt, Letter to William Thayer, 1915 July 2
Nashton
> On Dec 27, 1:14 pm, "Vanman" <Vancan...@shaw.ca> wrote:
>> Greetings all.
>>
>> In speaking with creationists it seems most I have met say initially that
>> they don't believe in evolution and then change their mind regarding
>> micro-evolution (which still makes them supporters of evolution btw). Of
>> course they deny macro-evolution as god made everything according to its
>> kind (a definition of which many seem to slither around conveniently).
>>
>> Just as we do not see languages evolve (anyone discover evidence of
>> Norwegian or Apache existing somewhere between the middle east and where
>> these groups ended up?..lol) there is (as far as I know) no explicit
>> evidence of macro-evolution per se.
>
> This is untrue. There is plenty of evidence for macroevolution.
> Speciation has been observed numerous time, especially in plants. In
> addition, the genetic evidence is rather overwhelming. Look at the
> presence of endogenous retroviruses in human and chimp DNA for an
> example.
>
> Chris
You have no idea what ERV are or what they represent, given your stupidity.
Stop being such a parrot.
Gene Poole
> chris thompson wrote:
>> On Dec 27, 1:14 pm, "Vanman" <Vancan...@shaw.ca> wrote:
>>> Greetings all.
>>>
>>> In speaking with creationists it seems most I have met say initially
>>> that
>>> they don't believe in evolution and then change their mind regarding
>>> micro-evolution (which still makes them supporters of evolution btw). Of
>>> course they deny macro-evolution as god made everything according to its
>>> kind (a definition of which many seem to slither around conveniently).
>>>
>>> Just as we do not see languages evolve (anyone discover evidence of
>>> Norwegian or Apache existing somewhere between the middle east and where
>>> these groups ended up?..lol) there is (as far as I know) no explicit
>>> evidence of macro-evolution per se.
>>
>> This is untrue. There is plenty of evidence for macroevolution.
>> Speciation has been observed numerous time, especially in plants. In
>> addition, the genetic evidence is rather overwhelming. Look at the
>> presence of endogenous retroviruses in human and chimp DNA for an
>> example.
>>
>> Chris
>
> You have no idea what ERV are or what they represent, given your stupidity.
>
> Stop being such a parrot.
By all means, please elaborate on /your/ theory on ERVs. We're all
dying to find out what they /really/ mean.
mur...@tntech.edu
> chris thompson wrote:
> > On Dec 27, 1:14 pm, "Vanman" <Vancan...@shaw.ca> wrote:
> >> Greetings all.
> >> Just as we do not see languages evolve (anyone discover evidence of
> >> Norwegian or Apache existing somewhere between the middle east and where
> >> these groups ended up?..lol) there is (as far as I know) no explicit
> >> evidence of macro-evolution per se.
>
> > This is untrue. There is plenty of evidence for macroevolution.
> > Speciation has been observed numerous time, especially in plants. In
> > addition, the genetic evidence is rather overwhelming. Look at the
> > presence of endogenous retroviruses in human and chimp DNA for an
> > example.
>
> > Chris
>
> You have no idea what ERV are or what they represent, given your stupidity.
So why don't you tell us what they are and what they represent? I'm
sure we'll all learn something, because you've got a degree... in
science!
[...]
---DPM
Burkhard
Ye Old One
Polar and Grizzly have different habitats but have interbred in
captivity. In very resent times, due to the loss of Polar Bear habitat
forcing more frequent meetings, it does look like there has been some
wild matings as well.
http://en.wikipedia.org/wiki/Grizzly-polar_bear_hybrid
>
>Thanks.
Also, if you have access to the National Geographic Channel, their
documentary "Morphed - Before They Were Bears" gives a very good
insight into bear evolution.
--
Bob.
The day Microsoft makes something that doesn't suck is probably the
day they start making vacuum cleaners.
chris thompson
> chris thompson wrote:
> > On Dec 27, 1:14 pm, "Vanman" <Vancan...@shaw.ca> wrote:
> >> Greetings all.
>
> >> In speaking with creationists it seems most I have met say initially that
> >> they don't believe in evolution and then change their mind regarding
> >> micro-evolution (which still makes them supporters of evolution btw). Of
> >> course they deny macro-evolution as god made everything according to its
> >> kind (a definition of which many seem to slither around conveniently).
>
> >> Just as we do not see languages evolve (anyone discover evidence of
> >> Norwegian or Apache existing somewhere between the middle east and where
> >> these groups ended up?..lol) there is (as far as I know) no explicit
> >> evidence of macro-evolution per se.
>
> > This is untrue. There is plenty of evidence for macroevolution.
> > Speciation has been observed numerous time, especially in plants. In
> > addition, the genetic evidence is rather overwhelming. Look at the
> > presence of endogenous retroviruses in human and chimp DNA for an
> > example.
>
> > Chris
>
> You have no idea what ERV are or what they represent, given your stupidity.
>
> Stop being such a parrot.
Thank you for your input, such as it is.
If you think you understand the significance of endogenous
retroviruses, by all means take this opportunity to explain it in
detail and make me look bad. Be sure to explain why they are not
evidence of common descent between human and other great apes.
You've only succeeded in making yourself look bad to this point.
Chris
Will in New Haven
The Brown/Grizzly Bears of North America were divided into numerous
species by the biologists of the time. They apparently did not
notice.
--
Will in New Haven
Will in New Haven
Actually, the fact that they _can_ mate and reproduce shows that these
two species have a recent common origin. Also, the Brown Bears of the
ABC Islands off of Alaska are closer genetically to Polar Bears than
to other populations of Brown Bears.
I would call Brown Bears and Polar Bears an example of _recent_
separation of species. They can still reproduce when they meet in the
wild. Lions and Tigers can reproduce when they are put together in
captivity but there is no evidence of the few remaining Asiatic Lions
in the Gir Wilderness of India ever interbreeding with Tigers.
Lions and Tigers and Bears, oh my
Will in New Haven
> > On Dec 27, 1:14 pm, "Vanman" <Vancan...@shaw.ca> wrote:
> >> Greetings all.
>
> >> In speaking with creationists it seems most I have met say initially that
> >> they don't believe in evolution and then change their mind regarding
> >> micro-evolution (which still makes them supporters of evolution btw). Of
> >> course they deny macro-evolution as god made everything according to its
> >> kind (a definition of which many seem to slither around conveniently).
>
> >> Just as we do not see languages evolve (anyone discover evidence of
> >> Norwegian or Apache existing somewhere between the middle east and where
> >> these groups ended up?..lol) there is (as far as I know) no explicit
> >> evidence of macro-evolution per se.
>
> > This is untrue. There is plenty of evidence for macroevolution.
> > Speciation has been observed numerous time, especially in plants. In
> > addition, the genetic evidence is rather overwhelming. Look at the
> > presence of endogenous retroviruses in human and chimp DNA for an
> > example.
>
> > Chris
>
> You have no idea what ERV are or what they represent, given your stupidity.
>
> Stop being such a parrot.
>
Stop being such a shit-eating dung bird.
And die
r norman
Of course they didn't. But later biologists did notice and have been
fighting about it ever since. Wikipedia lists all the brown bears as
subspecies of Ursus arctos
http://en.wikipedia.org/wiki/Brown_Bear
However, as you point out in a different post, one "subspecies" is
closer to Polar Bears than to other brown bears.
David Hare-Scott
You are asking for explanation? He doesn't have any, all you will get is
insults.
David
Bob Casanova
in talk.origins, posted by Nashton <na...@na.ca>:
>chris thompson wrote:
>> On Dec 27, 1:14 pm, "Vanman" <Vancan...@shaw.ca> wrote:
>>> Greetings all.
>>>
>>> In speaking with creationists it seems most I have met say initially that
>>> they don't believe in evolution and then change their mind regarding
>>> micro-evolution (which still makes them supporters of evolution btw). Of
>>> course they deny macro-evolution as god made everything according to its
>>> kind (a definition of which many seem to slither around conveniently).
>>>
>>> Just as we do not see languages evolve (anyone discover evidence of
>>> Norwegian or Apache existing somewhere between the middle east and where
>>> these groups ended up?..lol) there is (as far as I know) no explicit
>>> evidence of macro-evolution per se.
>>
>> This is untrue. There is plenty of evidence for macroevolution.
>> Speciation has been observed numerous time, especially in plants. In
>> addition, the genetic evidence is rather overwhelming. Look at the
>> presence of endogenous retroviruses in human and chimp DNA for an
>> example.
>You have no idea what ERV are or what they represent
Then please tell the group exactly what endogenous
retroviruses are and what they represent. And please tell
the group why Chris' statement was inappropriate regarding
the subject.
>, given your stupidity.
I'm sure you can demonstrate your superior intelligence and
grasp of the subject by responding to my request above.
>Stop being such a parrot.
Who or what did he parrot?
--
Bob C.
"Evidence confirming an observation is
evidence that the observation is wrong."
- McNameless
Stuart
Well, that is not quite the criteria, reproductive isolation doesn't
require
that offspring are not possible. For example, the beluga whale and
dolphin
can produce offspring, but that would not happen in the wild.
Reproductive isolation basically means that members of different
populations
don't recognize each other as potential mates.
Stuart
r norman
wrote:
Actually, even that doesn't often work. Effective reproductive
isolation means that under natural conditions hybridization is a rare
enough event so as not to confuse the issue too greatly. Essentially,
you just shut your eyes to the fact that it happens and hope you can
get away with it, at least for some time. If it gets too bad, you
just bite the bullet and redefine what the species is.
The problem is far, far greater in plants than in animals and, for
plants, "recognizing potential mates" is sort of a tricky proposition.
Will in New Haven
> On Sun, 27 Dec 2009 15:08:37 -0800 (PST), Stuart <bigdak...@gmail.com>
The various citrus sp are downright slutty.
Mike Lyle
>>
>> The problem is far, far greater in plants than in animals and, for
>> plants, "recognizing potential mates" is sort of a tricky
>> proposition.
>
> The various citrus sp are downright slutty.
Yeah, but I like that in a fruit.
--
Mike.
john wilkins
No, that's the Specific Mate Recognition Concept of Paterson. It is a
Reproductive Isolation conception, but not *the* RI conception.
Greg G.
wrote:
Who doesn't like a lemon that's a little tart?
Paul J Gans
That's a problem, isn't it. Can we set up mandatory education
centers where other mammals can be educated as to what their
species is and how to obey the boundaries that ought to impose?
Of course it will be a bit harder to get through to plants. I
understand that although they will sit still for long lectures,
their retention rate isn't too high.
And I'd just give up on single-celled things. Who cares about
them anyway?
:-)
--
--- Paul J. Gans
Paul J Gans
That's what we would expect, right? If the polar bears split
off from a subpopulation of brown bears, this is what we'd get.
And just think, the population of brown bears descended from the
ancestral population that was parent to the polar bears didn't even
go extinct!
In other words, it is all laid out there for anyone to see. Evolution
in action.
Paul J Gans
Damn dumb bees. They need a manual.
Paul J Gans
And, rereading the top of this, it should be noted that languages
most certainly DO evolve.
Paul J Gans
Can reproductive isolation involved conception?
r norman
Oops, I misunderstood who "they" were! Damn pronouns without proper
antecedents.
r norman
The bees tend to go after one 'kind' of flower at a time. It is the
wind that is the real problem.
Paul J Gans
Well, these creationist types keep bringing up problems that
we need to solve. Can't keep it all straight all the time.
SkyEyes
> Just as we do not see languages evolve (anyone discover evidence of
> Norwegian or Apache existing somewhere between the middle east and where
> these groups ended up?..lol)
Er, hate to bust your bubble, but *of course* we see languages
evolving. Norwegian is one of the North Germanic languages related to
Swedish, Danish, Faroese, and Icelandic. All those languages
developed out of Old Norse.
And the languages (there are more than one) of the Apaches are
examples of the many Athabascan tongues. Apache languages are very
close to Navajo (another Athabascan group); Apaches and Navajos can
usually understand one another, just like people from England and
people from Arizona can. Shared elements of these Athabascan tongues
have been found in certain dialects spoken in Western Mongolia.
And if you need more evidence that languages evolve, pick up a copy of
Chaucer in the original, and try reading it.
Brenda Nelson, A.A.#34
skyeyes nine at cox dot net
SkyEyes
Orange you sorry you started this pun cascade?
Brenda Nelson, A.A.#34
BAAWA Knight
EAC Professor of Feline Thermometrics and Cat-Herding
chris thompson
wrote:
Granted it has only been a few hours, but we are still waiting for
Nashton's explanation of endogenous retroviruses.
This issue will not go away. Nashton has called me stupid, and unless
and until he can provide a reasonable, non-evolutionary explanation
for this phenomenon, I plan to keep bringing it up.
The fact is, Nashton would not know a lemur from a lima bean, and he
would not know a virus from a grapevine.
Please, Nashton, expound to your heart's content on ERVs.
And after that, explain why a cheap effective treatment for malaria-
the second-deadliest killer in the world- is not a big deal.
There's more but we can start with those, thanks.
Chris
(looking forward to being ignored)
Paul J Gans
>On Dec 27, 5:35 pm, "Greg G." <ggw...@gmail.com> wrote:
>> On Dec 27, 6:56 pm, "Mike Lyle" <mike_lyle...@REMOVETHISyahoo.co.uk>
>> wrote:
>>
>> > Will in New Haven wrote:
>>
>> > > On Dec 27, 6:22 pm, r norman <r_s_nor...@comcast.net> wrote:
>> > [...].
>>
>> > >> The problem is far, far greater in plants than in animals and, for
>> > >> plants, "recognizing potential mates" is sort of a tricky
>> > >> proposition.
>>
>> > > The various citrus sp are downright slutty.
>>
>> > Yeah, but I like that in a fruit.
>>
>> Who doesn't like a lemon that's a little tart?
>Orange you sorry you started this pun cascade?
I apple to you all to stop this pungent production.
>Brenda Nelson, A.A.#34
>BAAWA Knight
>EAC Professor of Feline Thermometrics and Cat-Herding
>skyeyes nine at cox dot net
--
--- Paul J. Gans
Greg G.
AnswersInGenesis says that ERVs are not junk. They were inserted to
speed adaptation immediately following the flood.
JoeBussen
common. My favorite example is the Hawaiian silversword alliance
(google silversword alliance for photos and more), 30-50 species in 3
genera, all from a single immigrant (a W North American tarweed).
Inter-species hybrids are very common, and even inter-genera hybrids
occur.
When I descend Sliding Sands Trail into Haleakala (was there two
weeks ago to catch the Geminid meteor shower), I always look for the
Argyroxiphium (silversword) X Dubautia hybrids. The two genera are so
dissimilar, you have to see it to believe it.
chris thompson
<cheep cheep>
Nashton, you are a coward.
But- have a nice day.
Chris
Stuart
Conception be done about this?
I know, I know.. read your book.
Stuart
john wilkins
Iain
> Greetings all.
>
> In speaking with creationists it seems most I have met say initially that
> they don't believe in evolution and then change their mind regarding
> micro-evolution (which still makes them supporters of evolution btw). Of
> course they deny macro-evolution as god made everything according to its
> kind (a definition of which many seem to slither around conveniently).
First things first: -- micro- and macro- evolution are both observed.
That mere fact alone pretty much highlights how out of touch
creationists are with ... everything. They listen to each other more
than anyone else, and so end up constructing a reality bubble in which
you can pretty much say what you like and it won't bump up against
hard fact.
Macro-evolution is micro-evolution interpenetrated by instances of
speciation. Observing this is a trifling matter.
Why, then, are creationists so enamoured with the whole micro- \
macro- thing?
Creationists are always on the lookout for some kind of concept, idea,
or piece of jargon which would allow them to reject the long history
of evolution(which involves common descent), without rejecting the
brute facts which have been observed. It is common descent, and the
superfluity of a designer, which creationists cannot stomach.
To this end, jargon such as macro-\micro- seems like a ready-made
godsend. So at some point or another, someone started the mantra that
the latter had 'not been observed', and that general arrangement gives
them some sort of piece of mind.
> Just as we do not see languages evolve (anyone discover evidence of
> Norwegian or Apache existing somewhere between the middle east and where
> these groups ended up?..lol) there is (as far as I know) no explicit
> evidence of macro-evolution per se.
Quite! I made that point a couple of days ago when I posted this link.
http://www.youtube.com/watch?v=Rex35sG55nc
> Nevertheless I was thinking the other
> day that there are around 8 species of bears. Now it is my undestanding that
> the definition of a species is where two animals can create offspring.
> NJevertheless can someone please confirm for me that a Grizzly and Polar
> Bear cannot mate and create offspring? �If that is the case to me that would
> be pretty strong evidence of macro-evolution would it not?
Yes, you're right, but it's a bit more hopeless than that. The
Creationists often don't even know that that's what macroevolution
is.
If you go back in a time machine, at no point will you see a style of
evolution which cannot be observed today.
That's true of language, and it's true of life.
--Iain
Xavier Onnasis
news:hh99v5$mea$1...@reader1.panix.com:
> SkyEyes <skye...@cox.net> wrote:
>>On Dec 27, 5:35 pm, "Greg G." <ggw...@gmail.com> wrote:
>>> On Dec 27, 6:56 pm, "Mike Lyle"
>>> <mike_lyle...@REMOVETHISyahoo.co.uk> wrote:
>>>
>>> > Will in New Haven wrote:
>>>
>>> > > On Dec 27, 6:22 pm, r norman <r_s_nor...@comcast.net> wrote:
>>> > [...].
>>>
>>> > >> The problem is far, far greater in plants than in animals
>>> > >> and, for plants, "recognizing potential mates" is sort of a
>>> > >> tricky proposition.
>>>
>>> > > The various citrus sp are downright slutty.
>>>
>>> > Yeah, but I like that in a fruit.
>>>
>>> Who doesn't like a lemon that's a little tart?
>
>>Orange you sorry you started this pun cascade?
>
> I apple to you all to stop this pungent production.
>
<shrug> if you can't take it man, go elsewhere
--
XO
Greg G.
wrote:
That's a grape idea, but you can take it for pomegranate that they
threaten you with assault and pepper you with insults.
Paul J Gans
Oh, sorry. Let's try that again:
Can reproductive isolation involve conception?
Paul J Gans
>Paul J Gans <gan...@panix.com> wrote in
>news:hh99v5$mea$1...@reader1.panix.com:
>> SkyEyes <skye...@cox.net> wrote:
>>>On Dec 27, 5:35??pm, "Greg G." <ggw...@gmail.com> wrote:
>>>> On Dec 27, 6:56 pm, "Mike Lyle"
>>>> <mike_lyle...@REMOVETHISyahoo.co.uk> wrote:
>>>>
>>>> > Will in New Haven wrote:
>>>>
>>>> > > On Dec 27, 6:22 pm, r norman <r_s_nor...@comcast.net> wrote:
>>>> > [...].
>>>>
>>>> > >> The problem is far, far greater in plants than in animals
>>>> > >> and, for plants, "recognizing potential mates" is sort of a
>>>> > >> tricky proposition.
>>>>
>>>> > > The various citrus sp are downright slutty.
>>>>
>>>> > Yeah, but I like that in a fruit.
>>>>
>>>> Who doesn't like a lemon that's a little tart?
>>
>>>Orange you sorry you started this pun cascade?
>>
>> I apple to you all to stop this pungent production.
>>
><shrug> if you can't take it man, go elsewhere
I *am* elsewhere.
Xavier Onnasis
^^^^^^^
http://en.wikipedia.org/wiki/Mango
>
> I *am* elsewhere.
>
I yam sorry if you misinterpreted my previous message.
I hope the clarification above gets at the root of the
problem.
--
XO
john wilkins
Yes. Barriers to conception, like genetic
mismatch or cytological incompatibility are classed as prezygotic
isolation.
John Harshman
be postzygotic. The dividing line is formation of a zygote, you see.
chris thompson
> john wilkins wrote:
> > Paul J Gans <gan...@panix.com> wrote:
What exactly is meant by "cytological incompatibility"? Isn't one form
of this the inability of the sperm to fertilize the egg? That's
usually because an inappropriate hyaluronidase. That would seem to be
prezygotic.
Chris
r norman
I can't conceive that Paul Gans has any misconception about
reproductive conception. There is no deception in the reception of
his perception, without exception.
John Harshman
If I'm remembering right, it's often used to refer to incompatibility
between mitochondrial and nuclear genomes, which would of course become
apparent only in the zygote.
Ernest Major
<jhar...@pacbell.net> writes
>chris thompson wrote:
>> What exactly is meant by "cytological incompatibility"? Isn't one
>>form
>> of this the inability of the sperm to fertilize the egg? That's
>> usually because an inappropriate hyaluronidase. That would seem to be
>> prezygotic.
>
>If I'm remembering right, it's often used to refer to incompatibility
>between mitochondrial and nuclear genomes, which would of course become
>apparent only in the zygote.
>
IIRC, that situation is cytoplasmic incompatibility (which would also
include incompatibility between plastid and nuclear genomes).
Cytological incompatibility is a rare term (23 hits in Google), and
possibly of ill-defined application.
--
alias Ernest Major
Bob Casanova
talk.origins, posted by john wilkins <jo...@wilkins.id.au>:
Doesn't RI encompass *all* bars to reproduction between
otherwise-similar individuals which aren't specifically
genetic, i.e., geographic, temporal (reproductive season)
and potential mate recognition, plus any other similar ones
I can't think of?
Was that as clear as mud? ;-)
--
Bob C.
"Evidence confirming an observation is
evidence that the observation is wrong."
- McNameless
john wilkins
In my taxonomy of species conceptions, any conception that relies on
barriers to (sexual) reproduction is an RI conception, yes.
john wilkins
But if the sperm and egg cannot form a zygote, due to these factors, is
that not prezygotic?
John Harshman
postzygotically. Apparently I don't know what cytological
incompatibility is, so forget that part.
John Harshman
In fact cytoplasmic incompatibility is what I was thinking of.
Apparently I don't know what cytological incompatibility is, if it's
something different.
r norman
I believe that a real "reproductive isolating mechanism", that is, a
factor effectively separating species, must be a genetically
determined factor. Mere physical separation is a barrier to sexual
reproduction but it doesn't count.
john wilkins
My view is roughly the same, although I think it has to be
developmental, not genetic alone, but others will employ different
criteria.
r norman
I am not sure what you mean by "developmental" unless you mean
expressed in the phenotype. And, of course, if it is not expressed,
then it doesn't work!
The genetic requirement, of course, is essential for it to be part of
a species notion so that it can be passed on down the line. (yes,
memes can be passed culturally, but that is a different story for a
different subject).
Sorry about the failed dinner invite, but we will be on a tour and the
routing is not our own. Approaching my ninth decade (if you count
right -- actually I just reached 70 but I was alive during the 30's
and we soon be into the 10's), having people handle the luggage and
all the transportation and all the arrangements and details is a real
blessing.
Paul J Gans
>Paul J Gans <gan...@panix.com> wrote in news:hhaqm2$mjc$3...@reader1.panix.com:
>> Xavier Onnasis <xavier.onnasis@mule_brokers.com> wrote:
>>>Paul J Gans <gan...@panix.com> wrote in news:hh99v5$mea$1...@reader1.panix.com:
>>>> SkyEyes <skye...@cox.net> wrote:
>>>>
>>>>>Orange you sorry you started this pun cascade?
>>>>
>>>> I apple to you all to stop this pungent production.
>>>>
>>
>>
>>><shrug> if you can't take it man, go elsewhere
> ^^^^^^^
> http://en.wikipedia.org/wiki/Mango
>>
>> I *am* elsewhere.
>>
>I yam sorry if you misinterpreted my previous message.
>I hope the clarification above gets at the root of the
>problem.
Likewise. "yam" seems a bit obscure.
Paul J Gans
How to respond.... how to respond....
John was nice enough to seriously answer. My intent was to note
that when I am reproductively isolated, there's no sex at all,
much less conception.
<sniff, sniff>
el cid
> On 29 Dec 2009 02:58:57 GMT, john wilkins <j...@wilkins.id.au> wrote:
>
>
>
>
>
> >r norman <r_s_nor...@comcast.net> wrote:
> >> On 29 Dec 2009 00:36:10 GMT, john wilkins <j...@wilkins.id.au> wrote:
>
> >> >Bob Casanova <nos...@buzz.off> wrote:
> >> >> On 28 Dec 2009 00:39:09 GMT, the following appeared in
I recall an etymologist friend from about 16 years ago who
told me that in some beetles the mechanism of speciation
was that the male and female parts could no longer fit
together yet in the lab they could cross fertilize. Seems
like authentic reproductive isolation to me.
Reminds me of a limerick.
Here is the story of Nigel Knock
the only man with a corkscrew
BREAK
NO CARRIER
John Harshman
Was that intentional?
> friend from about 16 years ago who
> told me that in some beetles the mechanism of speciation
> was that the male and female parts could no longer fit
> together yet in the lab they could cross fertilize. Seems
> like authentic reproductive isolation to me.
That's true for a number of insects, not just beetles. That's one of
them prezygotic isolating mechanisms.
> Reminds me of a limerick.
>
> Here is the story of Nigel Knock
> the only man with a corkscrew
Look up "duck penis".
> BREAK
> NO CARRIER
>
r norman
It was a strange etymologist indeed who was expert on the reproductive
biology of insects! Vladimir Nabokov was certainly expert on words
and on butterflies and might qualify.
Yes, what you describe is the classical "mechanical" reproductive
isolating mechanism -- the sex organs don't match. It is very common
in arthropods. I have seen a taxonomic key for crayfish which bases a
lot of species definitions on tiny little changes in the first pair of
swimmerets (abdominal appendages) in males. These are used to carry
the sperm from the genital pore on the base of the fifth walking leg
in males to the genital pore on the base of the third walking leg in
females. If the grooves are not exactly right, matching the exact
location of the pores, the sperm can't make the trip properly.
My guess is that somebody in the lab was giving those beetles a little
aswsistance in the process.
The structure of the reproductive organs is, of course genetically
determined (and developmentally expressed).
Ernest Major
<r_s_n...@comcast.net> writes
recognition mechanisms. This opens up the possibility of a reproductive
isolating mechanism that is not genetically determined. I suppose that
this could be tested by swapping eggs between the nests of closely
related species in such groups.
--
alias Ernest Major
r norman
I was aware of learned bird song and worried about that before posting
about the genetic requirement. I strongly suspect that learned
patterns of behavior might produce varieties or subspecies. A species
level separation would not be reached without other reproductive
isolating factors acting together to block hybridization by
individuals who deviate from the behavioral "standards" of their type.
As long is individuals can migrate between types, taking up the
behavior of the adoptive group, the genes will remain well mixed
although the behaviors remain quite separate. Here I am thinking of
human groups where immigrants quickly take up the language or even the
religion of their new group so that neither language nor religious
affiliation, though quite distinctive, has any genetic foundation.
But there are scientific studies of bird behavior and reproductive
isolation that suggest you are right.
Ernest Major
Loxia curvirostra complex, but otherwise the group is formed of
genetically similar populations differing in vocalisations, beak
anatomy, preferred food species, and degree of nomadism. Reports are
that the different call types don't interbreed when sympatric.
A birding web site
(<URL:http://www.birdwatch.co.uk/website/content/view/2955/103/>)
mentions that there may be 30 or more cryptic species lumped into Loxia
curvirostra, in addition to the parrot and Scottish crossbills.
--
alias Ernest Major
r norman
<{$to$}@meden.demon.co.uk> wrote:
Sometimes I wonder about all those cryptic species groups. I imagine
members of those groups puzzled about the strange human
single-mindedness about visual distinctions. I can hear them saying,
"Just blurph at those guys over there, they smorg entirely different.
Sex with them? Yuk!"
Bob Casanova
Thanks; that's what I thought. It seems awfully broad to be
useful except as a general inclusive concept.
Bob Casanova
in talk.origins, posted by r norman
<r_s_n...@comcast.net>:
But doesn't such separation invariably lead to genetic
isolation in any case where the populations remain
separated?
chris thompson
> In message <tmqij5p3pe4566mh5umbe8mualfva82...@4ax.com>, r norman
> <r_s_nor...@comcast.net> writes
>
> >On 29 Dec 2009 00:36:10 GMT, john wilkins <j...@wilkins.id.au> wrote:
>
> >>Bob Casanova <nos...@buzz.off> wrote:
> >>> On 28 Dec 2009 00:39:09 GMT, the following appeared in
That's been done, and IIRC the result was somewhat of a jumble. The
conclusion was that the chicks have a template, and exposure to an
incorrect song (even during incubation; the parents sing to the eggs)
does not often result in the chick learning the new song, but rather a
pastiche of new on top of basic components of the old.
Looking up the stuff....
This is a lot newer than the papers I was thinking of, but it seems
typical:
Lars Erik Johannessen, Tore Slagsvolda and Bo Terning Hansena. 2006.
Effects of social rearing conditions on song structure and repertoire
size: experimental evidence from the field. Animal Behaviour 72: 83-95
ABSTRACT:
Through a cross-fostering experiment, we studied song learning of blue
tit, Cyanistes caeruleus, and great tit, Parus major, males reared by
heterospecific parents. This was done in the wild, and so potential
song tutors, territorial neighbours, potential mates and other social
factors were all natural and not affected by the treatment. Normally,
the song repertoires of the two species are completely discrete.
However, the cross-fostered great tit males altered their song in
several aspects, including repertoire size and composition, and
temporal and frequency parameters, thus becoming intermediate between
the normal songs of the two species. For the cross-fostered blue tit
song, only repertoire composition was affected. However, an analysis
of repertoire size in both species proved this to be larger in cross-
fostered than in control males. This increase in repertoire size shows
that repertoire size is influenced by social conditions in these
species and is not strictly constrained by memory capacity.
Furthermore, several of the cross-fostered great tit males included
trilled songs in their repertoires. In these two species, trilled
songs have been regarded as unique to the blue tit. In conclusion, our
results show the importance of early social experiences for song
learning in these wild tits.
Chris
r norman
Ofl course (though not "invariably"). That is the standard scenario
of allopatric speciation. But until there really is genetically
determined reproductive isolating mechanism, then the species are not
considered separate because reuniting them willl result in
hybridization.
Learned behavior as a reproductive isolating mechanism is another
story. I don't care for it but I can see enough research done with
bird song to let me think it might be sufficient. Of course, given
time, that learned mechanism will have added to it other, genetically
determined, mechanisms to clinch the deal.
r norman
wrote:
There are two technical nits to pick. First, I was not talking about
the general processes of reproductive isolation, where mere
geographical separation or belonging to a celibate religious ourder
will count. I was talking about the technical term "reproductive
isolating mechanism" which is considered the true key to speciation.
Wikipedia says "The different mechanisms of reproductive isolation are
genetically controlled ...".
http://en.wikipedia.org/wiki/Reproductive_isolation
Second (and related to a separate branch of this thread), there is
some confusion as to just how to divide the mechanisms -- into pre-
vs. post-zygotic and pre- and post- mating or pre- and
postfertilization mechanisms. I believe the zygotic break (counting
steps up to and including fertilization as pre-) is the more modern
distinction whereas the mating or fertilization break is more
historic. Getting the sperm to the egg is mating but getting the
sperm to recognize the egg and so enter it is fertilization. Whether
the fertilized cell can actually live as a zygote because of
mismatched genetic systems (whether nuclear or mitochondrial or
plastid) is sort of right in the middle, depending on just where you
draw the line. The ability of the zygote to live (temporarily) but
not divide properly is then necessarily post- everything no matter
where you draw the line.
Walter Bushell
<2a703c05-7aba-4be5...@a6g2000yqm.googlegroups.com>,
Stuart <bigd...@gmail.com> wrote:
> On Dec 27, 2:39�pm, john wilkins <j...@wilkins.id.au> wrote:
> Conception be done about this?
>
> I know, I know.. read your book.
>
> Stuart
That is a specious argument.
--
A computer without Microsoft is like a chocolate cake without mustard.
John Wilkins
<jhar...@pacbell.net> wrote:
I gather there are surface molecules on the ovum that the sperm
"recognise" or not in order to inseminate. Specific differences can
prevent insemination.
John Wilkins
<nos...@buzz.off> wrote:
It is, as I said, a taxonomy of conceptions, not the working definition
of any scientist. The version I most like is Alan Templeton's Cohesion
SC.
r norman
wrote:
There are indeed a whole series of steps involved in cell-cell
recognition before fertilization. The problem, though, is how to
describe failures that occur after the sperm has entered and before
the fertilized egg can divide. That is, how to describe failures of
the zygote, itself. These are neither prezygotic nor postzygotic,
merely zygotic.
OK, it is far more difficult in a technical sense that that. In the
human case, the sperm does not even fertilize a true ovum but,
instead, fertilizes the secondary oocyte. The "fertilized" cell then
undergoes a cell division, the completion of meiosis II, with the
sperm nucleus tucked off to one side. The sperm nucleus does not merge
with the egg nuclus until after that cell division, well after the
technical "fertilization" step.
The prezygotic/postzygotic distinction is merely a guidline in trying
to divide reproductive isolating mechanisms into more easily treated
groups. It can't encompass every possible scenario: nature is much
too imaginative to allow itself to be put into cubbyholes that easily.
As I already indicated in a different post, the historical division
involved either fertilization or mating, not zygote formation.
Bob Casanova
Makes sense; thanks.
>Learned behavior as a reproductive isolating mechanism is another
>story. I don't care for it but I can see enough research done with
>bird song to let me think it might be sufficient. Of course, given
>time, that learned mechanism will have added to it other, genetically
>determined, mechanisms to clinch the deal.
That's why I said "invariably"; if the populations remain
isolated indefinitely (geographically or otherwise) such
mechanisms would seem to me to be inevitable.
Bob Casanova
in talk.origins, posted by r norman
<r_s_n...@comcast.net>:
Thanks again. I've been following the discussion about this,
but as a layman I had nothing to contribute and so kept
quiet in hope of learning something. I think I did.
Bob Casanova
in talk.origins, posted by John Wilkins
<jo...@wilkins.id.au>:
That's become obvious with the posts in the thread; thanks
to all.
> The version I most like is Alan Templeton's Cohesion
>SC.
OK. For reference, here's a link to a synopsis of the
various species concepts, including Templeton's:
http://eebweb.arizona.edu/faculty/birky/ECOL600ALectures/SpeciesHandout.pdf
John Wilkins
<nos...@buzz.off> wrote:
Ignore the "Typological" SC: it never existed. Mayr took ordinary
practice of museums and elevated it to a "concept" that could be
contrasted with his own view.
John Wilkins
<nos...@buzz.off> wrote:
Oh, and see
http://ncse.com/evolution/science/species-concepts-modern-literature
Burkhard
speciate in the woods?
John Wilkins
<b.sc...@ed.ac.uk> wrote:
Of course not. They speciate in distinct ecotypes.
Bob Casanova
in talk.origins, posted by Burkhard <b.sc...@ed.ac.uk>:
No, no; the *Pope* speciates in the woods. Sheesh...
Bob Casanova
A bit of a plug, John? ;-)
I almost ordered this book when I bought your latest one,
but decided I'd spent my 2009 education allotment. Anyway,
thanks for the reference!
mur...@tntech.edu
> chris thompson wrote:
> > On Dec 27, 1:14 pm, "Vanman" <Vancan...@shaw.ca> wrote:
[...]
> >> Just as we do not see languages evolve (anyone discover evidence of
> >> Norwegian or Apache existing somewhere between the middle east and where
> >> these groups ended up?..lol) there is (as far as I know) no explicit
> >> evidence of macro-evolution per se.
>
> > This is untrue. There is plenty of evidence for macroevolution.
> > Speciation has been observed numerous time, especially in plants. In
> > addition, the genetic evidence is rather overwhelming. Look at the
> > presence of endogenous retroviruses in human and chimp DNA for an
> > example.
>
> > Chris
>
> You have no idea what ERV are or what they represent, given your stupidity.
>
> Stop being such a parrot.
>
Mr. "Nashton", now that you're back to posting, perhaps you'd like to
tell us what ERV's are, what they represent and why Mr. Thompson is
"stupid". And what you think he's parroting.
By the way, I'm very sorry for your recent illness. I'll assume it
was that which kept you from responding, and that you just didn't run
away like a coward.
---DPM
>
> >> Nevertheless I was thinking the other
> >> day that there are around 8 species of bears. Now it is my undestanding that
> >> the definition of a species is where two animals can create offspring.
> >> NJevertheless can someone please confirm for me that a Grizzly and Polar
> >> Bear cannot mate and create offspring? �If that is the case to me that would
> >> be pretty strong evidence of macro-evolution would it not?
>
> >> Thanks.- Hide quoted text -
>
> - Show quoted text -- Hide quoted text -
>
> - Show quoted text -