It works the way I think it does because it is literally how it developed.
I just did a quick look up of your claim of khoisans,
wiki
Origins
Further information:
Peopling of Africa,
Haplogroup L0 (mtDNA), and
Proto-Human_language § Phonemic_diversity
Further information:
Klasies River Caves,
Boomplaas Cave, and
Blombos cave
Approximate area of the origin of L0d and L0k haplogroups in southern Africa, dated to before 90,000 years ago by Behar et al. (2008).
[11]
It is suggested that the ancestors of the modern Khoisan expanded to southern Africa (from
East or
Central Africa) before 150,000 years ago, possibly as early as before 260,000 years ago,
[12][13] so that by the beginning of the
MIS 5 "
megadrought" 130,000 years ago, there were two ancestral population clusters in Africa, bearers of
mt-DNA haplogroup L0 in southern Africa ancestral to the Khoi-San and bearers of
haplogroup L1-6 in central/eastern Africa ancestral to everyone else.[
citation needed] This group gave rise to the
San population of
hunter gatherers. Their nearest living relatives are postulated to be the
Hadzabe people from north-central Tanzania; and
Mbuti pygmies from the eastern
Congo. A much later wave of migration, around or before the beginning of the
Common Era,
[14] gave rise to the Khoe people, who were
pastoralists.
[15] This group carried DNA from
Eurasian as well as some
Neanderthal groups.
======
So you are trying to claim a group that is noted to be one of the oldest african groups is descendant from a sub group that broke off , because again all people are from africa, and then came back in.
You realize how stupid you sound when you state what you state right? lol
The reality khoisans are a group from orignal humanity they remained but also intermixed with subgroups that broke off and came back to the region, ie they aren't derived from south asians they reabsorded south asians and neatherdals into them. smh.
Ainu Japanese - you can't see the african presence that is on you
Nakhi Chinese - african presence as well
So like I said before, the notion that you won't find groups all over this world that have the presence of african features, even if groups had broke off from africa and mated with cro-magnon and neaderthals of europe and became lighter and displayed different features is ridiculous on its face.