11–20 of 63 posts
Earlier quoted context omitted.
There is no top of the map since there is no objective frame of reference in space. The axis on which the Earth spins relative to its orbit is a point of orientation but which side is the "top" is arbitrary.
Yes, everybody knows that, and if someone asks me where Greenland is on a map, I will say "at the top" like a normal person.
On an extremely tangential note: I wish we would stop using the term, "Sub-Saharan." The semantic quandaries should be obvious, but it also subscribes to a curious linguistic glitch of putting the North and South into a hierarchy that only exists if you are rather incurious about the ambiguity of geographic perspective (see: the infamous "upside down" Gall-Peters projection for some mind-blowey fun). I would personal…
> (riffing on Asia Minor and referring to the fact that that part of the continent is, in fact, a majority of its landmass).
Isn't Asia Minor a bit more than half of Turkey? It's certainly not a majority of all of Asia...
For me, it's easier to understand these ideas by adopting a "lumper" mentality to human history. IE, Neanderthals, Denisovans, late Erectus & other archaics were just populations of humans. Sections on a large map of human diversity. On another section were, for example, that small subpopulation accounting for most modern human genetics. Near that little section were other subpopulations that even a "splitter" would…
Perhaps indirectly. As he addresses later in the text, it's possible that Denisovans in South East Asia encountered Homo erectus and interbred with them. The Denisovans appear to have more population structure as compared to Neanderthals, and introgression from H. erectus might explain some of it. Considering that South East Asia and Papua New Guinea has the highest Denisovan introgression in modern humans, it's possible that some of that H. erectus ancestry ended up in those of us from East of the Indus.
For what it's worth, I have seen other studies pop up from time to time that claim to have found introgression from some unknown ghost sapien population, but these outliers usually go away by tweaking the parameters.
For me, it's easier to understand these ideas by adopting a "lumper" mentality to human history. IE, Neanderthals, Denisovans, late Erectus & other archaics were just populations of humans. Sections on a large map of human diversity. On another section were, for example, that small subpopulation accounting for most modern human genetics. Near that little section were other subpopulations that even a "splitter" would…
the piece was not exhaustive and meant to be an intro
I thought this was an interesting article. Summarizing from my very-non-expert POV, he's dividing the world into three groups: a small number (less than 1 million) original African inhabitants; a larger number (about a billion) sub-Saharan Africans who broke off about 100,000 years ago; and then the rest-of-the-world (who went though a tight bottleneck less than 100,000 years ago) about the time they left Africa. The…
As a general rule, species start out with fairly high levels of diversity from natural processes of evolution. What happened with the out-of-Africa population is what's known as the founder effect. A small population leaves and becomes reproductively isolated. Whatever diversity can be found in their descendents is largely limited to the diversity that was present in the founding population. One thing that should be…
I had heard that there were several waves of migration towards Europe, do we have a better estimate about this? Wouldn't multiple waves over time provide more diversity?
On an extremely tangential note: I wish we would stop using the term, "Sub-Saharan." The semantic quandaries should be obvious, but it also subscribes to a curious linguistic glitch of putting the North and South into a hierarchy that only exists if you are rather incurious about the ambiguity of geographic perspective (see: the infamous "upside down" Gall-Peters projection for some mind-blowey fun). I would personal…
Putting aside the absurd nitpick on the "Sub-" prefix (everyone understands that this refers to "South" and not some position on a hierarchy). > (riffing on Asia Minor and referring to the fact that that part of the continent is, in fact, a majority of its landmass). Isn't Asia Minor a bit more than half of Turkey? It's certainly not a majority of all of Asia...
I subscribe to Razib’s substack. His writing style is a little weird and scattered, but he writes a lot about how this area of science is rapidly changing, and has good coverage of new hominid fossil discoveries.
Earlier quoted context omitted.
As a general rule, species start out with fairly high levels of diversity from natural processes of evolution. What happened with the out-of-Africa population is what's known as the founder effect. A small population leaves and becomes reproductively isolated. Whatever diversity can be found in their descendents is largely limited to the diversity that was present in the founding population. One thing that should be…
Do we have any idea about the size of the original population, the size of the group which left for Europe, the size of the group's who migrated to central/west Africa? I had heard that there were several waves of migration towards Europe, do we have a better estimate about this? Wouldn't multiple waves over time provide more diversity?
for the out of africa group i've seen sizes from 100 to 10,000. i used 1,000 to 10,000 as a likely moderate number, and the range also points to the census size being larger
we can assume that conditional on the size of OoA the other groups were way larger (10x or more). otoh, the main thing i did not explore is that i am now believing that africans themselves especially agriculturalists are 'compounds' of various bottlenecked groups (why west africans are closer to eurasians than they are to khoisan)
Earlier quoted context omitted.
As a general rule, species start out with fairly high levels of diversity from natural processes of evolution. What happened with the out-of-Africa population is what's known as the founder effect. A small population leaves and becomes reproductively isolated. Whatever diversity can be found in their descendents is largely limited to the diversity that was present in the founding population. One thing that should be…
Do we have any idea about the size of the original population, the size of the group which left for Europe, the size of the group's who migrated to central/west Africa? I had heard that there were several waves of migration towards Europe, do we have a better estimate about this? Wouldn't multiple waves over time provide more diversity?
For me, it's easier to understand these ideas by adopting a "lumper" mentality to human history. IE, Neanderthals, Denisovans, late Erectus & other archaics were just populations of humans. Sections on a large map of human diversity. On another section were, for example, that small subpopulation accounting for most modern human genetics. Near that little section were other subpopulations that even a "splitter" would…
> No introgression with other Sapien populations? Perhaps indirectly. As he addresses later in the text, it's possible that Denisovans in South East Asia encountered Homo erectus and interbred with them. The Denisovans appear to have more population structure as compared to Neanderthals, and introgression from H. erectus might explain some of it. Considering that South East Asia and Papua New Guinea has the highest D…
Were there other such groups, in or out of sub-saharan africa... whos genes we carry?