It might be simpler explanation. Homo Sapiens evolved in Africa where there are no long winter nights and huge variations of daily cycle throughout the year. Al

It might be simpler explanation. Homo Sapiens evolved in Africa where there are no long winter nights and huge variations of daily cycle throughout the year. Also humans can do shit in sunlight only. Like hunt. Then we moved to a different zone where there is longer nights and then we learned to do stuff that could be useful to be done "after hours". The pressure on good nights sleep immediately after dark lessened. Actually, people had to learn to work in the dark because in central and northern Europe there isn't much sunlight in the winter. Even in daytime there is usually overcast and no direct sunlight.