http://news.yahoo.com/s/ap/20060713/ap_ ... _evolution

WASHINGTON -

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.

The research was supported by the
National Science Foundation.
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It still boggles my mind that people deny this occurs.

Thank fucking goodness. Eat this creationists.

Ze finches are a neat group of species. Shame us humans won't evolve anytime soon.

Like I've said before, this jury is still out on whether the world was created or not.

Yeah, it would be cool if my kids had beaks

Ever read Galapagos by Vonnegut? Apparently we become hairless and develop flippers.

I thought this thread was going to be about the Darwin Awards.

Flippers for what? a "water world"?

I didn't think it was possible to predict future evolutionary change since there are so many different forcings (competition, resources, temperature, humidity, radiation, etc.) that could override the others and create negative or positive feedbacks.

Evolution has been observed numerous times in experiments using insects with extremely short lifespans, over the course of hundreds of their generations.



Thanks for the update.

Oh I know, it was just his theory and I thought it was funny. I was reading a National Geographic article about how walking upright both helps and harms the human body, so I think the next big step will be a change in our lower body and movement in general.

Ya, that was a great NG article. I liked it. They talked about how awkward and rare it is to find a bipedal mammal because. I had never thought about that before...

Me being flat-footed and having a lot of bad effects from it, it got me thinking a lot about the different configuratons that could be used. Maybe we'll start walking like ostriches.

It kind of sucks for humans, because each generation takes so long to mature and reproduce. Rabbits, on the other hand...

This thread is going well

At least we're all getting along.

Evolution in Escherichia Coli Bacterium Observed During Lab Tests
Jason Mick (Blog) - June 11, 2008 11:09 AM

E. Coli bacteria shows signs of evolution in lab testing

Despite an overwhelming body of scientific evidence, evolution is still a fiercely debate topic in some circles. From creationism to "intelligent design" many curious theories have been advanced with little scientific basis.

Many people take evolution for granted, simply understanding that it is the theory accepted by the scientific community based on the strong supporting evidence, and remain relatively oblivious to the controversy. However, the fact remains that yearly there are many protests and court cases in the U.S. and abroad where people try to block educational attempts to teach the theory of evolution and replace them with religious-based theories.

Fortunately for evolutionary scientists they now have perhaps the greatest piece of evidence of all -- the largest evolutionary leap observed to date. The experiment started inconspicuously, with researchers at Michigan State University in East Lansing by using a single Escherichia coli bacterium and its descendants to found 12 populations.

Over 44,000 generations were observed and only minor mutations were observed, as is typical in these kinds of studies. Typical beneficial mutations -- larger cell size, faster growth rates, and lower peak population densities -- were observed.

Then at generation 31,500 something shocking happened. The bacteria evolved, gaining an entirely new gene that could process citrate, a nutrient that the bacteria could not previously use. To put this in context, lack of citrate metabolism is one of E. coli's identifying traits. And the newly evolved bacteria proceeded to dominate over their citrate-intolerant kin.

Says researcher Richard Lenski, "It's the most profound change we have seen during the experiment. This was clearly something quite different for them, and it's outside what was normally considered the bounds of E. coli as a species, which makes it especially interesting."

Lenski says the only two explanations are either an extremely improbable mutation such as a rare chromosomal inversion, or a series of small mutation adding up to a useful new gene. Was the trait inevitable, guided by some all powerful hand? Lenski turned to his freezer for the answer. Unthawing the bacteria, from early generations, he found that pure chance had guided the evolutionary leap and that the bacteria did not evolve the trait. He did find that the later generations after 20,000 did evolve the trait eventually, indicating something happened around this time that laid the groundwork for the evolution.

He and his fellow researchers are currently studying exactly what change allowed for the eventual evolution. This experiment, however, proves that evolution does not always lead to best possible outcome (in that other lines did not achieve the same optimal trait). This has been a major point of contention raised by creationists who point to structures in nature that serve ornamental or little purpose as proof of creationism.

Further, it goes to show that profound changes can happen, including the introduction of entirely new genes. A particularly harsh criticism leveled in the past by was that profound genetic changes, including the creation of new genes, were never observed. Considering a few genes can account for profound morphological differences in larger organism, this is a very salient piece of evidence for evolution's supporters.

Jerry Coyne, an evolutionary biologist at the University of Chicago lauded the research and took a bit of an opportunity to poke fun at creationists saying, "The thing I like most is it says you can get these complex traits evolving by a combination of unlikely events. That's just what creationists say can't happen."

The findings are reported in the journal PNAS.


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Suck it anti-evolution people.

For those interested this (evolution, Galapogos finche's, Grant's research), there is a great book by Jonathan Weiner called "The Beak of Finches" that is an excellent read about evolution in action.

thanks for posting the story, and thanks for this. i'm interested in reading this, actually, quite soon. i hear it's excellent: