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>> The genetic evolutionary difference between distinct groups like Europeans, sub-Saharan Africans, ... is something like 70,000 years of divergent evolution w

>> The genetic evolutionary difference between distinct groups like Europeans, sub-Saharan Africans, ... is something like 70,000 years of divergent evolution with very very minimal gene flow between the groups. Any citation?

simonh 6y ago
The 'recent dispersal' started some 70-50,00 years ago, reaching Europe about 40,000 years ago. https://en.wikipedia.org/wiki/Early_human_migrations#Homo_sapiens https://en.wikipedia.org/wiki/Early_human_migrations#Homo_sa... Europeans have pretty low levels of sub-saharan genetic markers, with some remnant markets in southern Europe dating to the late Roman era, diminishing substantially as you move north. https://en.wikipedia.org/wiki/African_admixture_in_Europe https://en.wikipedia.org/wiki/African_admixture_in_Europe
- bsanr2 6y ago
  Low admixture, sure. And similarity of genetypes?
- etabetapi 6y ago
  This is tautological, sub-saharan genetic markers are found predominantly in sub-saharan populations by definition. Given how humanity has evolved, "european" markers are a subset of the diversity found in subsaharan populations that are overrepresented from founder effects, with very few exceptions. 40,000 years ago sounds like a long time, but it really isn't. You need an amazingly small amount of migration (about one person per generation) to keep a population in sync with each other genetically.
  - simonh 6y ago
    I get your point. I'm somewhat surprised that the person I was responding to seemed to think it would even need a citation, but there you are. >You need an amazingly small amount of migration (about one person per generation) to keep a population in sync with each other genetically. Well it depends on the size of the population, but even then I don't see how this can be the case. One individual only contributes half their genes to each child, so assuming 2 surviving children that's a 25% lost immediately in the next generation. In just a few generations about half the incomer's genes will be lost in this way. The remainder will likely persist, but equally the number of their descendants that have none or very few of their genes will rise to predominate. In a stable population of 1,000 people, one single individual is unlikely to contribute much more than 1/2,000th of the genes in circulation.

simonh 6y ago

The 'recent dispersal' started some 70-50,00 years ago, reaching Europe about 40,000 years ago. https://en.wikipedia.org/wiki/Early_human_migrations#Homo_sapiens https://en.wikipedia.org/wiki/Early_human_migrations#Homo_sa... Europeans have pretty low levels of sub-saharan genetic markers, with some remnant markets in southern Europe dating to the late Roman era, diminishing substantially as you move north. https://en.wikipedia.org/wiki/African_admixture_in_Europe https://en.wikipedia.org/wiki/African_admixture_in_Europe

bsanr2 6y ago
Low admixture, sure. And similarity of genetypes?
etabetapi 6y ago
This is tautological, sub-saharan genetic markers are found predominantly in sub-saharan populations by definition. Given how humanity has evolved, "european" markers are a subset of the diversity found in subsaharan populations that are overrepresented from founder effects, with very few exceptions. 40,000 years ago sounds like a long time, but it really isn't. You need an amazingly small amount of migration (about one person per generation) to keep a population in sync with each other genetically.
- simonh 6y ago
  I get your point. I'm somewhat surprised that the person I was responding to seemed to think it would even need a citation, but there you are. >You need an amazingly small amount of migration (about one person per generation) to keep a population in sync with each other genetically. Well it depends on the size of the population, but even then I don't see how this can be the case. One individual only contributes half their genes to each child, so assuming 2 surviving children that's a 25% lost immediately in the next generation. In just a few generations about half the incomer's genes will be lost in this way. The remainder will likely persist, but equally the number of their descendants that have none or very few of their genes will rise to predominate. In a stable population of 1,000 people, one single individual is unlikely to contribute much more than 1/2,000th of the genes in circulation.