There is much to say on this topic, and in order to get my point across in a few minutes, I did cut a lot o...
There is much to say on this topic, and in order to get my point across in a few minutes, I did cut a lot of corners.
The main point is that human evolution happened when we were hunter-gatherers, not recently, and that there were an awful lots of hunter-gatherers in the past who took part in the great experiment that is human evolution.
If I were to shoot this again, I would rewrite the script. You may notice that the no-incest and one-child-only rules, while they work fine for a few generations, get increasingly unrealistic as you go back in time. Once you have about 500 people on the top row of the chart, you have enough for a stable breeding network. Some of those people would be so distantly related that they really should be allowed to interbreed. So, instead of the population of the past's doing nothing but dying out from some ancestral vast population, it could instead remain constant for a while. In reality it would have waxed and waned. Many people would have had several children, and many would have had none, and not everyone was monogamous, of course.
This one isn't really a comedy sketch, like the others, so I'd rewrite it as one to fit in with the rest.