Free Wanderlust: A History of Walking by Rebecca Solnit Page A

biped.” He added that in the old pictures re-creating this phase of evolution, the creatures were strolling across the grassland; newer ones showed them in much more mixed habitat, and the most recent National Geographic articles had paintings that placed these creatures in forests with some of them in the trees. That the creatures were forest dwellers and tree climbers had become, Stern said, so obvious that no one bothered to credit Stern and Sussman for pushing the idea early on.
    The argument before had been circular: that hominids had learned to walk in order to venture onto the savannah, and that if they survived on the savannah, they must have been competent walkers. And the savannah seemed to be an image of freedom, of unlimited space in which the possibilities were likewise unlimited, a nobler space than the primeval forest that was less like the open forest of Rousseau’s solitary wanderers and more like the jungles from which Jane Goodall and Dian Fossey sent back their primate reports. Stern said a little later on, “I worry most about the manner of their bipedal walking. I wrote a papersaying they could not have walked as we do. It’s not fast, it’s not energetically efficient. . . . Are we wrong? Was their method of bipedalism actually pretty good?” Sussman cut in, “Or did they combine very good tree-climbing with shitty bipedalism and gradually the proportions reversed . . .” Stern continued, “The argument that I sometimes soothe myself with is that chimpanzees are really pretty crappy quadrupeds themselves, as four-footed animals go. So if they can be pretty crappy quadrupeds for seven million years, then we could’ve been pretty crappy bipeds for a couple of million years.”
    At the 1991 Conference on the Origins of Bipedalism in Paris, three anthropologists had reviewed all the current theories on walking as a kind of academic stand-up comedy routine. They described the “schlepp hypothesis,” which explained walking as an adaptation for carrying food, babies, and various other things; “the peek-a-boo hypothesis,” which involved standing up to see over the grass of the savannah; “the trench coat hypothesis,” which, like Guthrie’s theory that so amused Pat, connected bipedalism to penile display, only this time to impress females rather than intimidate other males; “the all wet hypothesis,” which involved wading and swimming during a proposed aquatic phase of evolution; “the tagalong hypothesis,” which involved following migratory herds across that ever-popular savannah; “the hot to trot hypothesis,” which was one of the more seriously reasoned theories, claiming that bipedalism limited solar exposure in the tropical midday sun and thus freed the species up to move into hot, open habitat; and the “two feet are better than four” hypothesis, which proposes that bipedalism was more energy-efficient than quadrupedalism, at least for the primates who would become humans.
    It was quite a collection of theories, though since talking to Stern and Sussman I had grown accustomed to the fluctuating interpretations of what to a lay person exposed to only one source sounds like established fact. The bones unearthed in Africa in ever greater quantity remain enigmatic in crucial ways, and the business of their interpretation recalls the ancient Greeks reading the entrails of animals to divine the future, or the Chinese throwing I Ching sticks to understand the world. They are constantly being rearranged to correspond to a new evolutionary family tree, a new set of measurements. Two Zurich anthropologists, for example, recently declared that the famous Lucy skeleton is actually that of a male, while Falk argues that she is not a human ancestor. Paleontology sometimes seems like a courtroom full of lawyers, each waving around evidencethat confirms their hypotheses and ignoring the