I’ve been rereading Darwin recently (for the first time since my creationist childhood) and came across the following passage in The Origin:
If it has taken centuries or thousands of years to improve or modify most of our plants up to their present standard of usefulness to man, we can understand how it is that neither Australia the Cape of Good Hope, nor any other region inhabited by quite uncivilised man, has afforded us a single plant worth culture. It is not that these countries, so rich in species, do not by a strange chance possess the aboriginal stocks of any useful plants, but that the native plants have not been improved by continued selection up to a standard of perfection comparable with that given to the plants in countries anciently civilised (The Origin of Species, pp. 95-96 in the Penguin Classics edition).
In Guns, Germs, and Steel, Jared Diamond argues the native peoples of America, Australia, and Africa advanced less rapidly than those of Eurasia in part because of the relative lack of large domesticable animals on those continents. At first glance Africa would seem to have plenty of horse-like, ox-like, and goat-like animals that could be profitably domesticated, but Diamond assures us that none of them are really suitable — that, for example, the zebra is far more bad-tempered than the horse or the ass and will often bite people.
Though I’m reluctant to take someone as an expert on animals who doesn’t know the difference between an aardvark and a hyena, let’s assume Diamond is right about zebras and other non-Eurasian megafauna. Darwin’s comment on plants quoted above, which would apply just as well to animals, offers a different interpretation. Diamond’s argument is that African animals are inherently unsuitable for domestication, that they were therefore not domesticated by the Africans, and that as a result the Africans remained relatively “uncivilized” (not that Diamond would use that word). Darwin’s logic suggests that the arrow of causation may go in the opposite direction. It’s possible that the Africans were a relatively uncivilized people, that they therefore failed to domesticate many animals, and that African animals were therefore not subjected to thousands of years of artificial selection and as a result remain far below the “standard of perfection” set by livestock of Eurasian origin.
I’m not saying that explanation is any more likely to be right than Diamond’s — assuming that non-Eurasian animals just happen to have been less “domesticable” is no more or less reasonable than assuming that non-Eurasian peoples just happen to have been less “civilized” — but it’s another possibility. Though not in the race-is-skin-deep camp myself, I think Diamond’s project is still the right idea. In the long run, all differences among various peoples, even the genetic ones Diamond so scrupulously ignores, have to be explained in terms of environment, since environment is what drives natural selection.