Angela
Elite member
- Messages
- 21,823
- Reaction score
- 12,329
- Points
- 113
- Ethnic group
- Italian
Since there's no section on the X I've put it here".
See: Skov et al
https://www.cell.com/cell-genomics/fulltext/S2666-979X(23)00034-4
"[h=2]Highlights[/h]
[h=2]Summary[/h]The X chromosome in non-African humans shows less diversity and less Neanderthal introgression than expected from neutral evolution. Analyzing 162 human male X chromosomes worldwide, we identified fourteen chromosomal regions where nearly identical haplotypes spanning several hundred kilobases are found at high frequencies in non-Africans. Genetic drift alone cannot explain the existence of these haplotypes, which must have been associated with strong positive selection in partial selective sweeps. Moreover, the swept haplotypes are entirely devoid of archaic ancestry as opposed to the non-swept haplotypes in the same genomic regions. The ancient Ust'-Ishim male dated at 45,000 before the present (BP) also carries the swept haplotypes, implying that selection on the haplotypes must have occurred between 45,000 and 55,000 years ago. Finally, we find that the chromosomal positions of sweeps overlap previously reported hotspots of selective sweeps in great ape evolution, suggesting a mechanism of selection unique to X chromosomes."
See: Skov et al
https://www.cell.com/cell-genomics/fulltext/S2666-979X(23)00034-4
"[h=2]Highlights[/h]
- •Strong reductions in X chromosome diversity among non-Africans
- •Positive selection spread long haplotypes across non-African populations
- •The selected haplotypes spread from a population without Neanderthal admixture
- •An ancient male genome dates these selective sweeps to 45,000–55,000 years BP
[h=2]Summary[/h]The X chromosome in non-African humans shows less diversity and less Neanderthal introgression than expected from neutral evolution. Analyzing 162 human male X chromosomes worldwide, we identified fourteen chromosomal regions where nearly identical haplotypes spanning several hundred kilobases are found at high frequencies in non-Africans. Genetic drift alone cannot explain the existence of these haplotypes, which must have been associated with strong positive selection in partial selective sweeps. Moreover, the swept haplotypes are entirely devoid of archaic ancestry as opposed to the non-swept haplotypes in the same genomic regions. The ancient Ust'-Ishim male dated at 45,000 before the present (BP) also carries the swept haplotypes, implying that selection on the haplotypes must have occurred between 45,000 and 55,000 years ago. Finally, we find that the chromosomal positions of sweeps overlap previously reported hotspots of selective sweeps in great ape evolution, suggesting a mechanism of selection unique to X chromosomes."