Tuesday, July 1, 2008

Birthdays all around!

Today is a terribly exciting day...

1. Happy Canada Day for all you Canadians and wannabes out there!

2. It marks 150 years since Darwin and Wallace read their paper on the theory of evolution by natural selection to the Linnean Society.

And please note the critical inclusion of "by natural selection". Evolution (the change noticed in species over time) had long been recognized by natural scientists. But the mechanism of natural selection, Darwin and Wallace's bright idea, was important for many reasons. For one, it introduced the idea of population, rather than individual, traits.

What was different about natural selection, compared to other ideas of the time, was that the critical changes occured in the species, not in individuals. This idea is now enshrined in the scientific method--scientists measure traits in large numbers of individuals because they realize each individual is unique and there is variation between individuals. What matters is the change to the population over time.

Secondly, natural selection introduced the idea of algorithms working in the natural world. The idea that a very simple set of automatic instructions can work with random mutation to produce the dizzying complexity we see in the natural world is immensely powerful.

So happy birthday to Canada and natural selection!

Oh! And if you live near Toronto, go see the Darwin exhibit. I hear it's awesome.

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