May 20 2009
Mockingbirds and Inadvertently Evolved Abilities
Research out of the University of Florida has revealed that mockingbirds can recognizes faces. Human faces. When individuals ventured too close to mockingbird nests on campus, on subsequent days these individuals would get targeted for a defensive attack by the birds much more quickly than other subjects. And their choice of clothing or angle of approach didn’t matter. They were recognized, flown at and “dive-bombed.”
And yet when different students approached the nests on the fifth day, the birds hardly ruffled their feathers, waiting to flush until last moment. They also gave fewer alarm calls and attacked much less than on the previous day with the familiar intruder.
Birds — at least mockingbirds — can recognize individual humans. What meaning can we make of this? Probably too much if we aren’t careful.
“We don’t believe mockingbirds evolved an ability to distinguish between humans. Mockingbirds and humans haven’t been living in close association long enough for that to occur.” Levey said. “We think instead that our experiments reveal an underlying ability to be incredibly perceptive of everything around them, and to respond appropriately when the stakes are high.”
You might say that the above specific behavior of mockingbirds evolved inadvertently. But there is probably a better word for it. Nonetheless, this point squarely addresses a logical fault rife in human thinking: the naturalistic fallacy. If a trait appears natural — it is widespread in a species — than it must have evolved. On purpose.
The other day I heard a tired version of this argument. It went: Because human “spiritual experiences” are widespread, human beings must have evolved to be spiritual beings.
Well, no. The patent falsity of this statement can be made obvious through the use of a whole number of ridiculous alternatives. Because human beings across the globe love alcohol, we must have evolved to get inebriated. Etc.
Whether in mockingbirds or human beings, there is great benefit in behavioral plasticity. Individuals that can apply their traits to new situations are more adaptable in their own lifetime. Furthermore, their plasticity provides something for evolution to shape in future generations.
Animals of all sorts will creatively apply their “natural” abilities to novel situations. Not because they have evolved to do it, but, in general, because plasticity is adaptive. Or can be. But not always.
