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On Our Own Two Feet

On Our Own Two Feet

By Katherine Yungmee Kim
October 2004

Upright: The Evolutionary Key to Becoming Human
By Craig Stanford
Houghton Mifflin Company, $24.00

Bipeds are bizarre.

So asserts USC College anthropologist Craig Stanford in his latest book, Upright: The Evolutionary Key to Becoming Human. “Of the more than two hundred species of primates,” Stanford writes, “one is bipedal. Of more than 4,000 species of mammals, one — the same one — is fully bipedal when walking.”

It is this trait — to stand upright and walk with two-footed locomotion — rather than language, tool use or brain size that sets humans apart. In his sixth book, Stanford, a primatologist and co-director of the Jane Goodall Research Center at USC, claims that “becoming bipedal made us human.”

Influenced by his 16 years studying primates in Africa and Asia, Stanford cites a critical moment of observation in Uganda’s Bwindi Impenetrable Forest. Several chimps were in a tree, and he watched them stand on their back legs — upright — to reach for figs overhead.

His theory goes like this: our ancestors stood on their feet to reach for food. Walking and running enabled us to be better hunters. Meat eating gave us bigger brains and a cognitive ability to evolve. Our hips shifted, changing the bones and muscles according to the new weight distribution, allowing us to stand up straight. Our newly freed hands were available for tool use and our opened diaphragms enabled a more fluid respiratory tract that provided us with the ability to speak.

Through piecing together fossil finds and animal behavior, and deconstructing anthropological orthodoxies, Stanford rejects the traditional narrative of human origins, of the familiar progression of hunched-over apes to hominids to humans. Rather than regarding ourselves as the apex of evolution, he says that we must recognize that we have been sculpted by natural selection.

“Bipedalism arose more than once in early human evolution,” Stanford comments. “Natural selection tinkered with bipedalism early on; some of these evolutionary experiments failed, a few succeeded and one ultimately led to us.” He goes on to say that humans are not part of an evolutionary ladder, but part of a tree — one with not only many branches, but with multiple trunks.

Stanford, who holds a joint appointment as chair of the anthropology department and professor of biological sciences, is also a professor at the Chinese Academy of Sciences. He is currently at work on a collaborative project with a grad student from Beijing, on the behavior and ecology of a rare golden Chinese monkey, a “shaggy, blue-faced, beautiful animal” that lives in large groups in the high mountains of China.

“I study primate behavior to literally and figuratively flesh out fossils,” Stanford explains.  “You look at a fossil and who knows what they did in real life. I look at the application of primate behavior to potential human origins.”
Meave Leakey, a paleontologist at the National Museums of Kenya and daughter-in-law of the preeminent anthropologists Louis and Mary Leakey, calls Upright a "thought-provoking” and “stimulating” account. “His unique perspective as an insider who has spent countless enthralling hours watching chimps and gorillas in their natural habitat, “ she writes, “makes this book particularly special.”