I’ve been reading The Ancestor’s Tale, by Richard Dawkins, which for me is a bit of escapism in the form of fascinating science writing. Dawkins has lots of tics, most irritatingly, the “tale” convention that forms part of the title, and whose use is repeated over and over again throughout, as he foreshadows “rendezvous” with evolutionary predecessors saying that story will be told in the chimpanzee’s tale, or the peacock’s tale, etc.
The nuggets like this passage on bipedalism, and there are many of them, make such annoyances worth putting up with, though: A stimulating suggestion is the sexual selection theory of Maxine Sheets-Johnstone, of the University of Oregon. She thinks we rose on our hind legs as a means of showing off our penise. Those of us who have penises, that is. Females, in her view, were doing it for the opposite reason: concealing their genitals which, in primates, are more prominently displayed on all fours…
A different set of theories stresses the freeing of the hands as the really important advantage of bipedality. Perhaps we rose on our hind legs, not because that is a good way of getting about, but because of what we were then able to do withour hands — carry food, for instance… The leopard uses its powerful jaws to hold the carcass, needing all four legs to climb the tree. Having much smaller and weaker jaws than a leopard, did our ancestors benefit from the skill of walking on two legs because it freed their hands for carrying food — perhaps back to a mate and children, or to trade favors with other companions, or to keep in a larder for future needs?
Incidentally, the latter two possibilities may be closer to each other than they appear. The idea (I attribute thisinspired way of expressing it to Steven Pinker) is that before the invention of the freezer the best larder for meat was a companion’s belly. How so? The meat itself is no longer available, of course, but the goodwill it buys is safe in long-term storage in a companion’s brain. Your companion will remember the favor and repay it when fortunes are reversed.