As a student of Comparative and Physiological Psychology, I spent an inordinate amount of time visiting zoos. If I was in a new city that had a zoo, I would make it a point to see it. If a city I lived in (or near) had a zoo, I visited it many times. I must have been at the Brookfield Zoo near Chicago at least 50 times; the Denver Zoo, 30 times; Detroit, maybe 10. I went to the zoo to watch the animals – not just the ones on display, but also the bipedal ones doing the looking. I took lots of photographs documenting various species typical behaviors, favoring mammals in general and primates in particular.
As part of my studies I read lots of scholarly works exploring evolutionary theory, including (in no particular order): Adaptation and Natural Selection, by George C. Williams, This View of Life, by G. G. Simpson; Animal Species and Evolution, by Ernst Mayer; Darwin’s Century and The Firmament of Time, by Loren Eisley; The Theory of Evolution, by John Maynard Smith; and, of course, The Voyage of the Beagle and The Origin of Species, by Charles Darwin (not to mention many, many brilliant essays by the late Stephen Jay Gould).
Have you heard anyone say that “Evolution is just a theory”? I’d like to point out that “Gravity” is also “just a theory.”
When people ask me if I “believe in evolution” I always answer, “No,” because evolution is a theory, not a belief. A theory is a systematic effort to unite a number of previously disparate physical phenomena using a common explanation. Theory is based on the scientific method of observation, experimentation, and verification. Belief, on the other hand, is based on philosophic methods – basically, trying to make sense of things just by thinking about them. It is possible to assess the rationality of a philosopher’s thought process, but how the original propositions are posed is wholly arbitrary, and has led to many thoroughly bizarre beliefs. Theory is based on observations; belief is based on ideas. Evolution is a theory; Intelligent Design is a belief
The focus of comparative psychology is to study the behaviors of different species and note similarities and differences between them. As you might expect, animals that are more closely related have the most similar behaviors. For example, Bengal Tigers and Serval Cats are vastly different in size, but have many cat-like behaviors in common. On the other hand, Servals can leap 12 to 15 feet in the air to capture birds in flight. Tigers can’t. But tigers can bring down a water buffalo, a feat that Servals cannot hope to do. These behavioral differences are not just based on size, but also on types and availability of prey. Both size and predatory behaviors are likely adaptations to their respective habitats.
Our nearest relatives, evolutionarily speaking, are the primates. We can see a lot of human-like behavior in monkeys and apes, and a lot of monkey- and ape-like behaviors in humans. For example, my pet squirrel monkey, Samantha, loved grapes, cheddar cheese, Jello, and lots of other things that I also enjoy. Her favorite food, above all others, was fresh, live mealworms. I always guessed that I would love them, too, but never got quite drunk enough to try them. Samantha’s trash disposal system was perfectly adapted to living in a rain forest, but not particularly suited for an environment consisting of a couple of home-made climbing trees standing on a linoleum floor: She dropped everything — out of sight, out of mind. And you wonder why people throw trash out their car windows or let it accumulate in their front yards?
I had heard good things about the Cheyenne Mountain Zoo near Colorado Springs. Since it was less than two hours away from Denver, I decided to visit. The zoo had installed a modern Ape House a few years earlier, and I was anxious to see what they had done. The afternoon I visited was hot (but not humid – it was Colorado, after all) and I found the air-conditioned Ape House to be a comfortable respite after strolling through the other exhibits. The Ape House was huge, with large indoor spaces for the apes, viewable through almost floor to high-ceiling windows. The only thing separating the humans from the other apes was a brass rail about thirty inches off the ground. I had apparently arrived shortly after feeding time, because all the apes were napping. Other zoo visitors must have known that, because I was the only person present in that large exhibit.
My hopes of observing ape behavior were dashed, that is, until a young woman entered, looking hot and tired, and trying to entertain a young lad of about three years of age. She moved from window to window, pointing at the sleeping apes, trying to get him to pay attention to the main attraction of the display. Meanwhile, the boy had discovered the brass rail, and was at different times, hanging from the rail with one or both hands, lifting his feet off the ground; throwing one or both feet over the rail while hanging from the rail; and generally swinging hand over hand from one glass window to the next. All the while, his mother was trying to get him to “behave.”
I was delighted. In my view he was behaving in a perfectly appropriate fashion for his species in that environment. And I finally got to observe the natural behavior of a member of the ape family. The kid was literally hanging with the apes.