The Thinking World: Will Evolution in the Anthropocene Converge on Beings that Learn?

This article in the New York Times summarizes the recent scientific research on a problem I wondered about a few months ago: what happens to animals that navigate by starlight, when the stars are washed out by the city? As it turns out, there are many other animals that rely on celestial phenomena to move about. Dung beetles may walk a straight line by looking at the trail of the Milky Way. Seals appear to swim with consistency toward bright star-like objects in the sky.

They also mention the study I discussed previously, about Indigo Buntings. The birds were taught in artificial conditions to treat the bright star Betelgeuse as the pole star instead of the current north star, Polaris. Stephen Emlen, the scientist responsible for the study, is quoted interpreting the results this way:

This suggested that the bird’s stargazing skills were learned, not derived from some star map encoded in their genes…In the glittering dark, each young bunting had apparently spent some time looking up, studying, as the stars traced circles in the night sky.

If we accept his theory, it suggests that the birds may be clever enough to deal with the perpetual, gradual change in alignment of the night sky. They did not evolve with some fixed blueprint of specific stars. Even better, they were born with a rudimentary awareness of how celestial rotation works. 26,000 years, the period over which the Earth’s axis wobbles to point at different stars across the sky, is enough time for evolution to change an organism, but not that long a period when compared to the one hundred and fifty million years or more over which modern birds evolved from dinosaurs.

Here’s an off-the-cuff definition of animal learning to make sense of this situation. Learning is what animals do to survive when there is no time or opportunity to evolve. Animals learn when something about their environment changes too quickly for selection pressure to make a better bird, or beetle, or seal. At this point they can either (1) use their existing biological equipment to make use of the environment they have, or (2) die out or retreat from the environment that has changed.

Learning and evolution cooperate. Those individuals that learn are more likely to contribute their genes to the species, thereby increasing the pool of genes that contribute to learning. This suggests that an environment that changes quickly is likely to select not for any particular trait, but for beings that learn to live with change. In interesting times, only the smart animals survive. In a sense, it’s another way in which humans are making the world in their own image. If there is anything that distinguishes Homo sapiens besides the ability to think, it is the ability to cause environmental change on a different order of time than the cosmological, geological, or evolutionary timescales that preceded them. Thinking is fast by nature. Rapid change gives an advantage to learned adaptation over instinctive fitness. And when the environment changes really fast, within even the memory of living Homo sapiens, it may it favor animals who learn, too.