Tuesday, July 29, 2008

Think of it as evolution in action

NY Times science writer offers examples of evolution that's taken place in the last 40 years. These include:

...Evolution of beak size in finches in the Galápagos archipelago: Over the course of 30 years, annual measurement of finches shows that both body size and beak size evolved significantly. But they didn’t do so in a smooth, consistent fashion. Instead, natural selection jittered about, often changing direction from one season to the next.

...For many plants, including field mustard (a scrawny annual plant with little yellow flowers), a drought means a shorter growing season. A shorter growing season means that plants that flower earlier are more likely to leave seeds than plants that flower later — which are in danger of dying before they’ve finished reproducing.

...In 1971, five pairs of adult wall lizards (Podarcis sicula) were brought to the tiny Croatian island of Pod Mrčaru from the nearby island of Pod Kopište. These five pairs have since given rise to a thriving lizard population — and one that has developed some interesting differences from the lizards that live on Kopište....This study is one of the most intriguing I’ve come across. It suggests that arrival in a new environment can result in dramatic changes to an organism within fewer than 40 lifetimes.

...I haven’t even begun to mention the countless examples of pests that have evolved resistance to pesticides and bacteria that have evolved resistance to antibiotics, nor the thousands of laboratory experiments showing evolution in the simple environments of test tubes and petri dishes. Also omitted: several examples of new species that are in the process of forming (I want to look at these in a future column).

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