Not so very long ago we humans thought of ourselves as a separate creation—the pinnacle of God’s work—that had been granted dominion over nature. But then along came Darwin, and we discovered that we are related, through descent, to other animals. Despite this blow to our dignity we long maintained a polite fiction that we’re special enough to merit classification in our own scientific family—the Hominidae. In our minds at least, we thus maintained a comfortable distance from the apes. But the analysis of DNA put an end to that, with the demonstration that only 2 percent of our genetic code differs from that of the chimpanzees. Now we and chimps must share a twig in the family tree, and the Hominidae has been expanded to encompass the other “great apes”—chimps, gorillas, and orangutans.
That being said, we clearly differ from the other great apes in many ways, a fact elucidated in Anne Innis Dagg’s The Social Behavior of Older Animals. It’s a highly unusual work in that it treats an age group of organisms that has received little previous attention. It is also a commendably broad study—covering a diversity of species from parrots to primates. Humans and chimps, it turns out, value age in sexual partners very differently. In our species youth is prized, but among chimps the reverse is the case. Importantly, female chimpanzees (unlike female humans) do not experience menopause, and thus can remain fertile into old age.
Flo was one of the most sexually attractive female chimps in a troop studied by Jane Goodall. By the time Flo was forty, her teeth were worn down to the gums and her time as the dominant female in the troop was over, but she still managed to drive the boys crazy, attracting a string of suitors and mating fifty times in a single day. Researchers, wondering whether Flo was an anomaly, carried out an eight-year study of chimpanzee sex. In what seems to be something of an understatement of their results, they concluded that
chimpanzee males may not find the wrinkled skin, ragged ears, irregular bald patches, and elongated nipples of their aged females as alluring as human men find the full lips and smooth complexions of young women, but clearly they are not reacting negatively….
There is great variety in the ways older animals differ from younger ones—in both physical and behavioral manner. Older chimps may go bald, and leopards suffer faded spots, but not all creatures bear such badges of seniority. The plumage of geriatric swallows, for example, is indistinguishable from birds…
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