10,000 generations ago. Like the next one but less of a "solved game".
1000 generations ago - Old men coupling with young women reads as small-scale tribal society to me. Polygamy, pride-of-lions. Groups are small enough that village elders control the, uh, means of production. The bottleneck on food is natural stocks.
200-300 generations ago lines up with the dawn of civilization and large-scale farming (5-7000 years ago). The bottleneck on food is human labour. Young people are encouraged to start (reasonably) self-sufficient farming families, and the surplus is traded for, taxed, or stolen.
0-50 generations ago (1000AD+) ??? Cultural escape velocity is reached. Women are having children later than ever before, pointing to less risky lives, greater food security, and increased autonomy, but also a heavier load of cultural baggage. Becoming elves isn't all it's cracked up to be.
Also, before someone else says it, blah blah blah average vs median.