Yet more out-of-date Malthusianism from Diamond. Although he has no qualifications or training whatsoever in the fields of anthropology, sociology, or archaeology, none of this prevents him from making bald assertions that would never hold up under any sort of professional inquiry. Instead, Diamond is willing to assert claims that biologists let go of in the 1950s, in order to re/create his model of biological and ecological determinism. Utter rubbish.