What about Finches named Dennis? ;-)
Posted on 07/13/2006 1:21:13 PM PDT by presidio9
Finches on the Galapagos Islands that inspired Charles Darwin to develop the concept of evolution are now helping confirm it — by evolving.
A medium sized species of Darwin's finch has evolved a smaller beak to take advantage of different seeds just two decades after the arrival of a larger rival for its original food source.
The altered beak size shows that species competing for food can undergo evolutionary change, said Peter Grant of Princeton University, lead author of the report appearing in Friday's issue of the journal Science.
Grant has been studying Darwin's finches for decades and previously recorded changes responding to a drought that altered what foods were available.
It's rare for scientists to be able to document changes in the appearance of an animal in response to competition. More often it is seen when something moves into a new habitat or the climate changes and it has to find new food or resources, explained Robert C. Fleischer, a geneticist at the Smithsonian's National Museum of Natural History and National Zoo.
This was certainly a documented case of microevolution, added Fleischer, who was not part of Grant's research.
Grant studied the finches on the Galapagos island Daphne, where the medium ground finch, Geospiza fortis, faced no competition for food, eating both small and large seeds.
In 1982 a breeding population of large ground finches, Geospiza magnirostris, arrived on the island and began competing for the large seeds of the Tribulus plants. G. magnirostris was able to break open and eat these seeds three times faster than G. fortis, depleting the supply of these seeds.
In 2003 and 2004 little rain fell, further reducing the food supply. The result was high mortality among G. fortis with larger beaks, leaving a breeding population of small-beaked G. fortis that could eat the seeds from smaller plants and didn't have to compete with the larger G. magnirostris for large seeds.
That's a form of evolution known as character displacement, where natural selection produces an evolutionary change in the next generation, Grant explained in a recorded statement made available by Science.
This might be true, but has our sun gone supernova yet?
Evolutionary changes occur with each generation. They don't usually create observable morphological changes.
Is this pre-emptive commentary?
Or maybe it's post-emptive; based on comments on prior threads?
You nailed it Widewake. Evolution is a theory about speciation. As in the "Origin of Species". Changing bill-size over generations is not - in itself - speciation.
Al Gore says this won't save them. They are all doomed.
Any genetic population shift is evolution. They describe how this finch population has undergone evolution due to competition - which hasn't been observed before.
People saying "ah but has [something else entirely] happened yet?" are reading something into this article that isn't there while simultaneously missing what is there. Quite a feat.
Maybe, but we won't know it for seven minutes.
What about Finches named Dennis? ;-)
IOW, Natural Selection.
Evolution is not a theory soley about speciation. It covers any genetic change in a population. Ie bacteria can evolve resistance to antibiotics even though they haven't changed species.
Nope, the finch aren't becoming anything else. They're still finch. A taller human is still a human -- and this isn't evolution any more than that... Now when the finch turns into a frog, ping me. That's evolution.
see #30
The REAL reason AP is reporting this is to counter the facts in Ann Coulter's book relating to the wacko-evolutionists and the creation argument. She mentioned the finches as another example of Darwinian argument errors.
Still the same species
LOL Gee, the sizes of the finch beaks has been a 'proof' of evolution for evol believers for a long time. Apparently, these birds change beak sizes like I change my shoes.
Coulter just repeats the anti-evolution literature, probably off some website or other. It's all nonsense. Many of the problems they cite with Darwin's finches are problems they have imagined through their lack of understanding of the matter.
how does a shorter beak equate to evolution? it could easily be attributed to global warming or more likely a statistical fluke in the measurements themselves.
Yeah, you coulda knocked me over with a ... no, I can't do it.
im not aware of anyone using finches as a "proof" of evolution. It's a demonstration of natural selection.
A fair clarification. But the word "Darwin" in the title kind of throws the theory of speciation into the ring :0)
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