Thursday, August 14, 2008

Evolution is happening in your local forest and fishpond

From the New York Times:

"Evolution should be taught — indeed, it should be central to beginning biology classes — for at least three reasons.

"First, it provides a powerful framework for investigating the world we live in. Without evolution, biology is merely a collection of disconnected facts, a set of descriptions. The astonishing variety of nature, from the tree shrew that guzzles vast quantities of alcohol every night to the lichens that grow in the Antarctic wastes, cannot be probed and understood...

The second reason for teaching evolution is that the subject is immediately relevant here and now. The impact we are having on the planet is causing other organisms to evolve — and fast. And I’m not talking just about the obvious examples: widespread resistance to pesticides among insects; the evolution of drug resistance in the agents of disease, from malaria to tuberculosis; the possibility that, say, the virus that causes bird flu will evolve into a form that spreads easily from person to person. The impact we are having is much broader.

For instance, we are causing animals to evolve just by hunting them. The North Atlantic cod fishery has caused the evolution of cod that mature smaller and younger than they did 40 years ago. Fishing for grayling in Norwegian lakes has caused a similar pattern in these fish. Human trophy hunting for bighorn rams has caused the population to evolve into one of smaller-horn rams. (All of which, incidentally, is in line with evolutionary predictions.)

Conversely, hunting animals to extinction may cause evolution in their former prey species. Experiments on guppies have shown that, without predators, these fish evolve more brightly colored scales, mature later, bunch together in shoals less and lose their ability to suddenly swim away from something. Such changes can happen in fewer than five generations. If you then reintroduce some predators, the population typically goes extinct...

The third reason to teach evolution ... concerns the development of an attitude toward evidence. In his book, “The Republican War on Science,” the journalist Chris Mooney argues persuasively that a contempt for scientific evidence — or indeed, evidence of any kind — has permeated the Bush administration’s policies, from climate change to sex education, from drilling for oil to the war in Iraq. A dismissal of evolution is an integral part of this general attitude.

Moreover, since the science classroom is where a contempt for evidence is often first encountered, it is also arguably where it first begins to be cultivated...

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