What a lot of reading to catch up...
We have genes. Many genes. Genes in all kinds of variety and combinations. The not so many genes coding for physical appearance go skindeep only and not telling that much on all the other genes.
So... why using the word "race" ?
A word that has been abused so much in the last centuries. So much variety in connotations that are not helpful for effective communication. And the word "race" is anyway not descriptive enough for all kinds of biological-medical effects ?
Some remarks/info
1.
In roughly 1500, many pairs of populations had been geographically, and therefore genetically, isolated for tens of thousands of years. E.g., Western Europeans and Bantu peoples. Tens of thousands of years is enough time for SNPs to build up and create population-level differences in many distributions of phenotypes. Melanin levels and eye color were not the only things affected. Americans who have most of their ancestors in Europe 500 years ago are more likely to have multiple sclerosis. Americans who have most of their ancestors in Africa 500 years ago are more likely to have sickle cell anemia. These are real differences in the distributions of diseases between these two populations.
Except from some islands and some really peripheral (and hard to travel or sustain) areas, tribes wandered all over Europe-Asia-Africa during those tens of thousands of years.
There were at the start of Homo Sapiens some issues to get out of Africa, but once the area of the Euphrates and the Tigris rivers were reached, nothing stopped further wandering in all directions,
continuously.
It did ofc happen that some tribes kept control over the area of origin of mutations until modern times, but in many cases the highest percentages of haplogroups are found hundreds, thousands of miles away from the origin.
If you just look at all the known major tribal wanderings crisscrossing through Europe between 100 AD and 600 AD, followed by many more up to 1100 AD, and then at the various Haplogroup percentages spread out over Europe or EuroAsia, with everywhere different percentages, with also often the assumed location of origin of the mutation having today a very low percentage.
Here a graph of tribal wanderings of 100-600 AD in Europe:
And here some graphs with % distribution of some of the Haplogroups, showing how far the carrier tribes wandered:
(On the site you can see also the tree of further subgroups as the origined from further mutations in the course of time, indicating the time line of their wandering)
https://www.eupedia.com/europe/Haplogroup_E1b1b_Y-DNA.shtml
The Y-DNA (male) Haplogroup E1b1b (formerly known as E3b) represents the last major direct migration from Africa into Europe. It is believed to have first appeared in the Horn of Africa approximately 26,000 years ago and dispersed to North Africa and the Near East during the late Paleolithic and Mesolithic periods. E-M78 and E-Z827 originated respectively at 20,000 years and 24,000 years. E1b1b lineages are closely linked to the diffusion of
Afroasiatic languages.
https://www.eupedia.com/europe/Haplogroup_R1a_Y-DNA.shtml
The Y-DNA Haplogroup R* originated in North Asia just before the Last Glacial Maximum (26,500-19,000 years before present). This haplogroup has been identified in the 24,000 year-old remains of the so-called "Mal'ta boy" from the Altai region, in south-central Siberia (Raghavan et al. 2013). This individual belonged to a tribe of mammoth hunters that may have roamed across Siberia and parts of Europe during the Paleolithic.
Here the migration percentage map of the
R1a haplogroup (evolved from those R* mammoth hunters)
This R1b* haplogroup below, evolved from R* (those mammoth hunters), is also interesting because tribes carrying them wandered deep into Africa, and domesticised the auroch into cattle (DNA research indicating that 80 individual aurochs were the arch base)
https://www.eupedia.com/europe/Haplogroup_R1b_Y-DNA.shtml
It has been hypothetised that R1b people (perhaps alongside neighbouring J2 tribes) were the first to domesticate cattle in northern Mesopotamia some 10,500 years ago. R1b tribes descended from mammoth hunters, and when mammoths went extinct, they started hunting other large game such as bisons and aurochs. With the increase of the human population in the Fertile Crescent from the beginning of the Neolithic (starting 12,000 years ago), selective hunting and culling of herds started replacing indiscriminate killing of wild animals. The increased involvement of humans in the life of aurochs, wild boars and goats led to their progressive taming. Cattle herders probably maintained a nomadic or semi-nomadic existence, while other people in the Fertile Crescent (presumably represented by haplogroups E1b1b, G and T) settled down to cultivate the land or keep smaller domesticates.
The analysis of bovine DNA has revealed that all the taurine cattle (Bos taurus) alive today descend from a population of only 80 aurochs. The earliest evidence of cattle domestication dates from circa 8,500 BCE in the Pre-Pottery Neolithic cultures in the Taurus Mountains. The two oldest archaeological sites showing signs of cattle domestication are the villages of Çayönü Tepesi in southeastern Turkey and Dja'de el-Mughara in northern Iraq, two sites only 250 km away from each others. This is presumably the area from which R1b lineages started expanding - or in other words the "original homeland" of R1b.
If you look at the Old World map showing the areas of the dominating haplogroup you get this graph below:
This map also shows with arrows the tribal wanderings from assumed origin location to areas with highest percentage today.
Do note that the R1b* haplogroup reached Cameroon, BTW very close to where "Adam" (Y-DNA haplogroup A*) is assumed to have started 250,000 years ago.
A00-AF6/L1284* has been found found in 6 living males in Cameroon.
https://www.marres.nl/haplogroepen.htm
2.
Historical tribal genocides and/or surpression/social stratification.
A. If you find in some ethnic group, or in some area with good boundaries much more diversity of mt-DNA Haplogroups (female ancestor line) than diversity of the Y-DNA Haplogroups (male ancestor line), it is more likely explained by social stratification processes in the past 250,000 years, like polygamy, slavery or genocide of mostly males (or as less likely case diseases that affected male only).
B. If you find however comparable diversity between mtDNA and Y-DNA, it is more likely that complete tribes were genocided, driven to less favorable habitats, or suffered from diseases (like imported from other tribes).
Reality ofc a mix of both processes.
An example of that social stratification process is Cuba according to this article (google translated):
(And no, I did not made the effort to find (and check) the original science articles, but so much of this source does fit sound info, that I believe it)
https://www.marres.nl/haplogroepen.htm
Recent replacement of the Y-DNA in Cuba:
A good example of the displacement of indigenous genes by a completely new gene package shows the genographic composition of the Caribbean island of Cuba. The island has been inhabited for 7000 years. In 1513 it became a Spanish colony. About 110,000 people lived there at the time. Now there are more than eleven million. The newcomers were Spaniards, but many Africans also entered the country as slaves.
In 2012, an admixture analysis was made from a group of 1,019 randomly selected residents. For this a mixture of autosomal, Y-DNA and mt-DNA diagnostic haplogroup markers was used. They found that the original Y-DNA haplogroups have almost completely disappeared. and for 99½. Two thirds of the mt-DNA haplo groups disappeared.
This process has also occurred in the imported population of black slaves, but to a much lesser extent. Their Y-DNA percentage is now half the expected percentage, compared to their mt-DNA percentage of almost 100%. (39)
The conclusion that we can draw from this is that with relatively peaceful domination the male DNA disappears almost completely, but the female DNA is largely preserved. If the latter also disappears, there will be eradication.
This lowering of male Y-DNA frequency, diversity (compared to female mt-DNA diversity) also happened around 50,000 years ago (the roll out into EuroAsia) and again strongly 6,000-2,000 BC (in Europe).
https://www.ncbi.nlm.nih.gov/pubmed/25770088
Abstract
It is commonly thought that human genetic diversity in non-African populations was shaped primarily by an out-of-Africa dispersal 50-100 thousand yr ago (kya). Here, we present a study of 456 geographically diverse high-coverage Y chromosome sequences, including 299 newly reported samples. Applying ancient DNA calibration, we date the Y-chromosomal most recent common ancestor (MRCA) in Africa at 254 (95% CI 192-307) kya and detect a cluster of major non-African founder haplogroups in a narrow time interval at 47-52 kya, consistent with a rapid initial colonization model of Eurasia and Oceania after the out-of-Africa bottleneck. In contrast to demographic reconstructions based on mtDNA, we infer a second strong bottleneck in Y-chromosome lineages dating to the last 10 ky. We hypothesize that this bottleneck is caused by cultural changes affecting variance of reproductive success among males.
The story of the many genes of Dzjengis Khan is well known. Perhaps he was "only" keeping up an old tradition of chieftain male genetic competition.
Our genetic history shows imo a continuous process of tribal wars and tribal surpressions, tribal expelling from good habitats.
We should really stop that.
Stopping using the word "race" a good start.
Aint life strange? I'm assuming our African ancestors 3-6 mya had pale skin hidden by black hair. We're all the most evolved, everyone can be traced back to the same small group somewhere near Ethiopia. I'd love to have a time machine and pay them a visit. And all the world was of one tongue and one culture.
