Life Grows and Changes

I love evolution so much it makes me cry. From writer Clive Thompson, on his blog Collision Detection:

Dig this: A group of researchers has discovered that red squirrels appear to be able to predict the future.

At least, the future of the forests in which they live. American and Eurasian red squirrels live in spruce trees, and love to eat spruce tree seeds. To try and thwart the squirrels, the trees long ago evolved an interesting defense: An unpredictable boom-and-bust period of seed production. The trees will produce several low-seed years in a row and then, boom, outta nowhere and seemingly at random, a bumper crop of seeds. The idea is that the trees will starve the squirrels in the lean years, thus reducing the squirrel population -- whereupon the trees will launch a massive seed offensive to try and frantically reproduce while the squirrels are on the ropes.

But here's the thing: The squirrels have fought back. A team led by Stan Boutin of the University of Alberta studied the squirrels' mating patterns, and Boutin found something remarkable: The squirrels appear to be able to predict when the trees are going to randomly produce a bumper crop. In a high-yield year, several months before the trees produce their seeds, the squirrels engage in a second mating cycle, doubling the size of their broods. The squirrels are somehow seeing into the future of the trees -- or at least making incredibly accurate bets.

I do feel like noting that this description takes the classic inverted view of evolution than the one I prefer: species don't TRY to become something else. The ones that are still around are the ones that did a certain thing. Individual ambition, while its own wonderful thing, has nothing to do with evolution. (Feel free to show some way that it is in a comment)

The trees aren't TRYing to be like that. The ones that started doing it are in fact the ones that are still around, even better than ones who, say, started a simpler alternation of high- and low-output years.

On the squirrel side, it's a bit more complicated. We can say for sure that the squirrels aren't meeting in committees and debating the evidence, and choosing as a society what to do. But I couldn't really say what's at work here. More study needed. It's possible that the ones that are still around are the ones that have a mating cycle that somehow matches the (certainly not random) cycle of the bumper crop years, but....how strange is all that?