I was surprised at the very conservative estimate of dog domestication, but you acknowledge that. Even though you don't explicitly say so, you give the impression that the bow and arrow was invented around 20K years ago, but the last thing I read was that there was pretty conclusive evidence which pushes that date back to some sixty thousand years ago.
I was also interested in the astronomical science, but I am not up to date on the latest theories. However, I was surprised you pointed out changes in the Earth's orbit (are you talking about precession or something else?) but made no mention of solar weather. I would expect that outside of life activities, changes in solar weather would be a more important variable than changes in the Earth's orbit.
Every time I bring up solar weather in the history of climate change, people automatically assume I am a denier of anthropogenic climate change. Of course I'm not. That's just stupid. I mean, forget about our out of control population and our internal combustion engines. What do you think is going to happen if you cut down all the trees? We were well on our way down this path by the Roman era. I hate to even have to say this, but if I don't, I know I'll get slapped with that label.