Sunday, May 30, 2010

Intelligence Outside Primates

(Picture from here.)

In the Will Farrel move, Land of the Lost, there's a set of scenes where the team is menaced by a T. Rex. Farrel keeps saying they don't have to worry about it because it's so stupid; it's got a brain the size of a walnut.

Later, there's a huge crash outside of the cave where they're hiding. The team comes out and sees this boulder sized object. "What is it?" says one. Says Farrel: "It's a walnut."

This describes the demise of the anthrocentric view of intelligence.

No one disputes the intelligence of us hairless monkeys. But we like to consider ourselves more than just smart apes. Wallace, Darwin's co-presenter at the initial offering of their papers on evolution, thought we were so special that we were outside of natural selection.

Well, over the years Jane Goodall and others have shown that we can find the roots of everything we do in our primate ancestors: tool using, proto-language communication, etc.

But we would expect that, wouldn't we? After all, we share more than 98% of the genetic material with chimpanzees. We only diverged a few million years ago. Jane Goodall thinks we should keep chimps in the same genus as human beings. Wouldn't our "specialness" just be redefined to be within our own little clade?

Well, it turns out: no.

Traits that are observed in animals are viewed as original or derived. Original traits are those that have arisen from the group under examination. Derived traits are those that come from the ancestral stem collection of which the examined group is a member. Hair, in mammals, is an original trait in that only mammals have it. The quality of having four limbs, however, is a derived trait that mammals inherited from their stem ancestors.

Birds derived from dinosaurs about 150 million years ago. Dinosaurs derived from reptiles about 230 million years ago. They synapsids (from which mammals originated) split from the sauropsids (from which the reptiles came) about 324 million years ago. I'd say it's a pretty safe bet that any intelligence showing up in birds came from a different ancestral origin than intelligence in, say, mammals.

Which brings us to Irene Pepperberger's work.

Doctor Pepperberg worked with the African gray parrot Alex for many years, teaching him a vocabulary and studying how he used it. Alex was able to understand and respond to a considerable range of questions, behavior, make demands and ask questions. These were not human responses. I was able to talk with Doctor Pepperberger some years ago at Boskone. The films she showed of Alex were truly remarkable. Not because of the symbolic reasoning and abstract perception that Alex was showing, but because how far from human they were. Alex was a wonderful bird. But his reasoning, from my quick observation of the films, was not a human reasoning. If you watch chimps and gorillas execute similar tasks the way they respond is eerily human.

Pepperberg's work is made even more interesting with the work done on crows. Crows have been shown to use tools to gather food in the file. Raves have been shown to use logic in solving problems. In this experiment, the ravens were given a complex task to complete. This is not the interesting part. Many animals can be trained to execute complex tasks. These ravens were given the task to figure out for the first time. They observed the situation and figured it out.

So: we see intelligence in birds. The next question is what are they using to execute intelligence?

Remember, mammals use the cerebral cortex for intellectual pursuits. But the cortex evolved in mammals after they split from reptiles. Therefore, intelligence in birds cannot use the same mechanism. Evolution of the brain is (roughly) in three parts: reptilian, paleomammalian and neomammalian structures. (See here.) The cortex is a neomammalian structure.

Therefore, birds cannot be using the same mechanism as humans. Which shouldn't surprise anyone. We have to use a big sweaty cortex to get things done. Birds do the same thing with something the size of your thumb.

Makes you think differently about dinosaur behavior, doesn't it?

I asked Doctor Pepperberg about this and she thought the structures of intelligence might be originating from the tectum. In non-mammalians it serves as the main visual area of the brain. The development of the mammalian cortex arises out of the embryonic tectum. Doctor Pepperberger also pointed out that the experiments required to demonstrate this sort of thing would be fatal to the subjects and so she wasn't interested in it.

The other component of human beings that people point to as "special" is empathy and altruism. Well, turns out birds might well be displaying these traits as well. (See here.) Research with ravens has shown that behavior remarkably like consolation between victims of aggression and the rest of the flock show up regularly.

There's a common discussion among scientists and science fiction writers about the likelihood of intelligence arising out in the universe. The word, "intelligence", here is a code word for "beings like us". Animals that build cities, engage in cooperative behavior, show up on television and litter the sky with satellites.

But "intelligence" is far broader than we first realized. Ravens, gorillas, chimpanzees, elephants, wolves, dolphins and even cephalopods have all shown themselves to solve problems, use tools and communicate in a sophisticated fashion. It seems to me that once you have a brain in place there's a selective advantage to use it that's limited only by the ability to keep it fed and full of oxygen.

That said, where humans are unique is the joining of intelligence with hands and a mysterious natural selection for more intelligence. Chimps have been chimps for a million years. Humans have advanced enormously just in the last few hundred thousand years.

Now that might be rare.

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