'Darwin's finches' revert to type

english.aljazeera.net ^ | May 4, 2006

[DBrow]

Strictly speaking, Darwin did not write about a direction to evolution (better and better, for instance) but spoke only of change.

If I remember correctly it was Darwin who described the now-extinct Irish Elk, who through continued selection wound up with antlers so huge the animal could not navigate a forest.

So in Darwinian theory, if a species moved all the way to a single-cell blob from a complex finch, that would not be de-evolution, just evolution from one state to another.

[RoadTest]

Wow! Evolution has reverse! And we thought it only had one speed.

[connectthedots]

Further evidence that natural selection is true and macro-evolution is false.

[CheyennePress]

Am I the only one who finds this a little suspect? Why would their beak sizes reverse so quickly? First of all, these birds have a much longer lifespan than the moths, so you wouldn't expect them to revert as quickly as the moths do.

Secondly, I wouldn't expect something as trivial as beak shape to so greatly impact the outlook of a species. With moths, you have a very clear selective advantage in camoflauge.

With beaks, you have a specialization, but change should occur slowly. Further, unless humans are destroying large swaths of habitat, the long-beaked birds should still have a survival advantage for their selected niche because they are best suited towards that food source (even if the other birds are best suited towards human habitation).

[mlc9852]

It is strange. Just wanted to see what everyone else thought about it.

[Robwin]

Ok, then, give me a call when these birds devolve back into reptiles, or snails, or bacteria, or whatever it is you Evos claim they evolved from.

[vpintheak]

I see, the birds are ADAPTING to their surroundings. But it sure sounds like they are still finches to me.

[2nsdammit]

Right, and wrong.

It is support for natural selection, since the beak size trait being selected for no longer matters, due to the introduction of new food sources (apparently).

This study says nothing about "macro-evolution". These birds were all members of the same species, which had been diverging, but now are not.

There are several (I think 14?) other species on the islands which HAVE diverged into separate species from a common ancestor.

[2nsdammit]

Read the sources, and try not to be so ignorant next time you make a comment....

[2nsdammit]

Correct. This study only intailed one species, which had appeared to be diverging, but were still able to produce viable offspring.

[Junior]

Just go on believing that as it makes you feel good -- regardless of the logical error you are making.

[shuckmaster]

What would an example of "reverse evolution" be?

It's your thread. You tell us!

[connectthedots]

There are several (I think 14?) other species on the islands which HAVE diverged into separate species from a common ancestor.

This has actually been observed; or is it speculation?

[mikeus_maximus]

Strictly speaking, Darwin did not write about a direction to evolution (better and better, for instance) but spoke only of change.

Then boy, he sure fooled Huxley! :)

[2nsdammit]

http://www.americanscientist.org/template/IssueTOC/issue/346

The first article discusses the speciation. The link below, (although long, sorry!) is a reprint. There is ample evidence to support the common ancestor theory; although I am sure that since the process took a while, you will deny that it happened, since no humans "observed" it.

http://chiron.valdosta.edu/jbpascar/Courses/Biol1010/ExtraCreditActivities/American%20Scientist%20Online%20-%20Adaptive%20Radiation%20of%20Darwin's%20Finches.htm

[js1138]

All evolution is microevolution.

[Elpasser]

On THAT we can agree.

[CarolinaGuitarman]

"This was a fake study."

Not at all.

"The moths were pinned on the trees for the photos taken and did NOT rest on either light or dark areas per se."

Not true. There were one or two photos that had both color patterns side by side that had the birds pinned down, because it is hard enough to find the moth let alone both color varieties together. It was simply used as an illustration of the two color varieties. ALL of the other pictures were of ONE moth that was photographed undisturbed on the tree trunks. The study was in no way faked and this charge has been refuted time and time again.

"Most evos know it was fake by now and like to sweep it under the rug, it is embarassing for them to mention it."

What's embarrassing is how anti-evos, who ostensibly attack evolution because it is supposed to lead to immorality, have no trouble lying through their teeth about what this study showed.

[connectthedots]

From the first link:In one model of how species form, geographical separation leads to evolutionary divergence. Recent evidence permits refinement of this model.

I've always said that evolution is not a theory; it is a model. No proof of evoulution there.

As for the second linked page, it 'cannot be found', just like proof for evolution.

[connectthedots]

From the first link:In one model of how species form, geographical separation leads to evolutionary divergence. Recent evidence permits refinement of this model.

I've always said that evolution is not a theory; it is a model. No proof of evoulution there.

As for the second linked page, it 'cannot be found', just like proof for evolution.