When my son was at ASU getting his PhD, he said ocassionally he bumped into Turner. I asked him a couple times to ask Turner this 'or that' question...I never heard a thing back, lol.
I don't like Jared Diamond's writing, albeit, I received and read his book "Collapse" as a present last Christmas. I liked his ideas about continental alignment and the possible consequences. His explanation of why the Africans never domesticated the Zebra was laughable...they were too mean, lol.
They are nasty critters but I think of the mahouts leading domesticated elephants around...I join you in lol!
Diamond mostly lost me with his knee-jerk statement that human overhunting in Australia and North America eliminated the megafauna. Maybe. But there are other (to me) more plausible explanations, like catastrophism-caused climate change that put an evolutionary premium on small body weight, speed, smarts and omniverousness.