Enough with the Finches Already

Every so often I get a chuckle out of some science writer in the mainstream media reporting a finding that "proves" evolution. Usually it's some new pronouncement of measurements of Darwin's finches on the Galopagos Islands.

Really! It proves evolution? I can't wait to read it!

So I wasn't disappointed to read this AP story this week, posted on FreeRepublic.com, called "Finches on Galopagos Islands evolving". Go read it and then come back and tell me how this proves evolution.

Are they claiming proof? From the article:

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.

Really? It evolved a medium beak? In just two decades? No need to read any further - hey they proved it already!

Oh, but wait a minute. Silly me. I read further, and I paid attention.

It seems that our finch in question (G. fortis), under a little competition for food in a dry season from mean ole G. magnirostris experienced a change:

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.

So, what dear readers are we to conclude from this - helped along by Peter Grant of Princeton University, lead author of the report:

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.

Ahh, no. It's not. In my humble opinion, it's not a "form of evolution" at all.

There's just one little hitch, and that is that the population of G. fortis had both medium beaks and large beaks all along. The finch didn't "evolve" a medium beak.
Only the ratio of those two beak sizes changed due to the environmental pressure. Give it a couple rainy seasons and the ratio will swing back to favor the large beaks.

This is just a rehash of the famous "peppered moth" story from England that has been used for so many years to demonstrate natural selection. It's bogus and proves nothing. It only proves variation in the ratio of traits within an existing population. It has nothing to do, for example, with speciation.

Bottom line: this quaint little study does not "prove" evolution. An existing trait (beak size) varies with environmental pressure - granted. However, the finch did not "evolve" a medium beak. The finch did not become anything but a finch.

It's a meaningless story.

And, it's not the last time we will hear it.