Other chromosomes

From 24 to 23 pairs of chromosomes

Homo sapiens, Neanderthals, and Denisovans have 23 pairs of chromosomes while Homo erectus, chimpanzee have 24 pairs of chromosomes. The No.2 chromosomes in the former is the fusion of No2. and No.3. chromosomes of the latter. It caused the reproductive isolation.

Y chromosome length is shortening

The length of Y chromosome is shortening in the last million years. I guess the man with shorter Y-chromosome is tend to reproduce more descendant.

Monoamine Oxidase A

Monoamine Oxidase A (MAOA) gene is in the X chromosome.

Minmum number of homo sapiens

The minimum number of homo sapiens in history may be less than 1000 at global. The homo sapiens with Y-chromosomes O-MF567393(1035 BC) is also less than 1000 at global.