More important than the origin of the universe, more important than climate change, more important than curing cancer, more important than anything else...
Great write-up on a subject of interest to me.
good piece but please note there is an alternative framework to ghost populations to explain some of the genetic patterns https://www.razibkhan.com/p/current-status-its-complicated (the reality is probably a mix imo; at least in africa)
re: complexion. the khoisan have eurasian slc24a5 and it's under strong selection (selects for light skin). they probably got it from cushitic pastoralists who migrated southward before the bantus. they were probably darker in the past
re: sex differences in complexion. i haven't run the math...but sexually dimorphic features take about 10x longer to evolve because of the necessity of modifier genes (ie a gene for lighter or darker skin in one sex without the same effect in the other is a way more complex metabolic system than overall)