Michael Vassar is having trouble accessing this site right now, so asked me to relay this question:
You mention in your book (p. 69) that from 100,000 BC to 12,000 BC, the human population increased from half a million to six million thanks to better hunting tools and techniques. On the other hand, from page 100 onwards, you discuss Malthusian limits to population, implying that the sizes of primitive populations were proportional to the amount of food available. In other words, you seem to be saying that from 100,000 BC to 12,000 BC, the human population grew because better hunting techniques increased the availability of food.
But better hunting technologies won't generally tend to raise Malthusian limits strongly. While hunting better will mean that new prey become exploitable, it also means that old prey are continually hunted to extinction. The net result isn't a systematic trend. How strong is the evidence for any prehistoric population sizes? How do the implied population densities compare to those for other large omnivores, such as black bears and pigs, in their territories, or to the population densities at which Chimps live? Why would human densities have been much lower?
Better hunting techniques can significantly raise Malthusian limits.
First, you have to remember that old-fashioned humans were one predator among many: improved hunting techniques could raise our share of the pot, as well as decreasing other predators' tendency to eat us. Also, modern humans seem to have used carcasses more efficiently than Neanderthals: they had permafrost storage pits and drying racks, so could have preserved meat for long periods. Neanderthals didn't, and I think they must have wasted a lot. Next, moderns used snares, ...
Edit: Q&A is now closed. Thanks to everyone for participating, and thanks very much to Harpending and Cochran for their responses.
In response to Kaj's review, Henry Harpending and Gregory Cochran, the authors of the The 10,000 Year Explosion, have agreed to a Q&A session with the Less Wrong community.
If you have any questions for either Harpending or Cochran, please reply to this post with a question addressed to one or both of them. Material for questions might be derived from their blog for the book which includes stories about hunting animals in Africa with an eye towards evolutionary implications (which rose to Jennifer's attention based on Steve Sailer's prior attention).
Please do not kibitz in this Q&A... instead go to the kibitzing area to talk about the Q&A session itself. Eventually, this post will be edited to note that the process has been closed, at which time there should be no new questions.