Niles Eldredge - The Darwin Blogs

The Darwin Blogs – July 9, 2006.

Bonobos: Creationism’s Worst Nightmare—And Some News

Creationists since time immemorial have been throwing up every sort of objection they can think of to the very idea of evolution—the notion that all organisms on earth, whether alive or long-since extinct, are descended through a natural process of ancestry and descent from a single common ancestor living billions of years ago.

But scratch a creationist and you soon reveal the true essence of his concerns: what really bothers a creationist is not so much how trilobites and dinosaurs came into existence. What really bothers him is how he got here: a creationist can never square the notion that humans have evolved with their religious belief that humans were separately created by God in His own image. The roots of all morality are held to spring from that single, separate creative act. If there is one species on earth that is utterly separate from the rest of Creation, it is ourselves, species Homo sapiens—or so any creationist will tell you.

And, of course, in our self-conscious awareness of ourselves, with our language and highly developed culture, we do live a life markedly different from all other species. We alone use our knowledge and tools to plant, harvest and otherwise produce the foods we eat—the only species in the history of the planet no longer reliant on the fruits of the ecosystems in which we live for our daily sustenance.

But if we did indeed evolve, there should be hauntingly tell-tale traces of that descent. There should be a fossil record showing a progressive change from ape-like to modern human anatomy. There is. There should be genetic and comparative anatomical evidence linking us much more closely with some other species than with the rest of the organic realm. There is—we share over 98% of our genes with chimps, and the stunning matchup of the bones of our skeleton and those of chimps is striking.

And there should be some sort of hints that our fundamental behavioral features—possibly even our use of language—is not as unique to ourselves as pretty much all of us have traditionally thought.

Enter bonobos—the “pygmy chimp”—that other, less well known species of African chimpanzee that, with its sister species (plus mountain and lowland gorillas and so much else of the biota) is under imminent threat of extinction in the wild.

Bonobos are more like us than are their bigger relatives, the common chimp. Their facial features remain more rounded and baby-like—more like ours, less than the other chimps and gorillas. Bonobos are very social, and use frequent and “promiscuous” sex as a sort of social currency that helps reduce aggression within the troop and (as in humans) may also be exchanged for food resources.

But I was not aware of how really close these remarkable animals are to us—until I heard a fantastic report on NPR’s Weekend Edition for Saturday, July 8. Entitled “Exploring Language. A Voluble Visit with Two Talking Apes,” the show can be heard by visiting www.npr.org, clicking “Archive” and entering either the date or the title of the segment. It will be well worth your while.

Kanzi is a bonobo kept at a primate facility in Iowa. He, and his younger sister Panbanisha (who if anything has even more promising linguistic skills) can understand entire sentences—spoken in English by the main scientist there (Dr. Sue Savage-Rumbaugh)—and by other scientists and staff members, as well as casual visitors such as the NPR reporters.

Bonobos cannot make human sounds. Indeed, anatomists studying the bottoms of human fossil skulls long ago concluded that the modern shape of the human larynx (“voice box”) didn’t evolve fully until our own species came into existence some 150,000-200,000 years ago. So even a Neanderthal would have been incapable of making the full range of sounds we modern humans combine into speech.

So Kanzi and Panbanisha turn to their computer keyboards—where individual keys stand for individual words. They understand thousands of words and can respond in full sentences. Linguists, understandably skeptical that these apes truly have mastered so fully what has always seemed to be the purely human domain of verbal comprehension, helped devise tests—ruling out, for example, the subtle use of body language that might also be at play when Savage-Rumbaugh “talks” with Kanzi. Yet Kanzi always passes the test.

But there is more. I was struck with how sympathetic Kanzi seemed to be when he discovered that Bill Fields—another researcher—was missing one of his fingers. Kanzi asked if it hurt—and Fields said “not any more.” Kanzi was applying a concept of “hurting,” familiar to himself, to someone else.

I heard this interview while driving to our home in the Adirondacks after the ritualized morning visit to the store (primarily to buy the New York Times) and the garbage dump. When I heard the story of Kanzi’s concern that the missing finger might still hurt, I instantly flashed back 15 years or so ago to a lecture I heard by Nick Humphries—a British psychologist/animal behaviorist. Nick had showed a short film of chimpanzees sitting around in a group. Even to my human eyes, each chimp looked very different from one another—distinct individuals.

Humphries was looking for an explanation—a theory—for the evolution of human consciousness. He made the riveting suggestion that the best way to gain some insight into what was going on in someone else’s mind would be by consulting one’s own mind, and thinking what might be one’s own thoughts in a particular situation. Humphries was not saying that the chimps in his movie were already there—though they seemed as if some rudiments of this understanding were indeed already established in their minds. But the origin of human consciousness could be plausibly considered to lie in the advantage that such introspection could yield to members of a higher primate social band in the recesses of evolutionary time.

And that is just where Savage-Rumbaugh and her colleagues want to take the story of Kanzi and Panbanisha: towards a “theory of mind” where someone—me, you, Kanzi—realize that other people have beliefs and desires.

This is no mere carnival side-show, this “train the bonobos to talk” project. For the research makes crystal clear just how our close our closest living relatives actually had gotten in developing the basic cognitive skills that underlie our very human use of language—which is in turn the basis of all our culture.

Thank you Sue-Savage Rumbaugh, your colleagues—and of course Kanzi and Panbanisha—for establishing even closer ties between ourselves and our closest living relatives—and through them the rest of the vast organic world. It is no accident that Kanzi’s favorite movie is “Quest for Fire” (one of mine too!)—a movie that explores the stages of human evolution by imagining different groups, of varying stages of evolution, all living cheek-by-jowl in “land that time forgot” fashion. Though a work of fiction, the film evokes that chain of similarity that links all closely related species—a chain that links the more primitive forms with the later, more advanced forms. How poignant for Kanzi and Panbanisha who (their human caretakers maintain) are aware that, though they can communicate with us, they lack some of the critical skills and tools that would enable them to actually be us. Just like in the movie.

News Flash: Three young women have produced a video on Darwin that took them all the way to the national finals for National History Day. Entitled “Like Confessing a Murder. Darwin’s Reluctant Stand,” the film is well worth checking out at http://video.google.com/videoplay?docid=1772594371104013753&q=darwin+nhd

Niles Eldredge

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