[whimsicalism]

there were also a lot of sociocultural changes coming out of the 60s/70s that changed the scientific conclusions we drew.

it used to be that we saw changes in ancient pottery and language and assumed that previous people had been replaced by new people with different techniques. then, in the 60s/70s it became popular that these changes didn’t mark population replacement but were more cultural spread and shift.

then genetics came around in the 90s and obliterated the cultural hypothesis and showed that in most of these cases it was largely population replacement.

there are lots of theories from the mid-20th that haven’t yet had their ‘genetics in the 90s’ moment.

[PittleyDunkin]

> then genetics came around in the 90s and obliterated the cultural hypothesis and showed that in most of these cases it was largely population replacement.

I think the current consensus is a fusion of the two stances, particularly as some of the changes have appeared to be too rapid to reflect population displacement, and genetics clearly indicate genetic admixture with varying distinguishing characteristics relevant to the region and timeperiod as opposed to straight displacement.

Unsatisfying, I know, but basically any firm position on either side has equally firm arguments against it.

[whimsicalism]

I had a recent discussion about this, will try to pull up the sources, but my understanding is displacement is the majoritarian current and cultural shift with same population very much a secondary that only applies in a minority of the cases

a lot of these admixture events show near total displacement of the y chromosome also

[PittleyDunkin]

I'm not disbelieving your source entirely, but it seems a little ridiculous to assume population displacement across all pre-history (or undocumented history if you'd prefer that term). Particularly when modern populations are so genetically diverse.

For one example, the idea a single "sea people" were responsible for the shift from bronze age to iron age in the eastern mediterranean is nearly universally rejected at this point. The populations of the mediterranean seem to descend at least in part from the bronze-age populations of the area. However the economic and cultural impact of the same period undeniably transfused rapidly through the region as heavily demonstrated with the archaeological record.

Even in the case of neanderthals we didn't fully displace so much as mostly displace but also admixed. Same with denisovans, cro magnons, etc. Genetic testing of cro-magnons shows modern-day descendants, and not just in the matrilineal or patrilineal line (i.e. presumably indicating either descendants of rape or partial infertility, as is presumed in the case of neanderthals).

With the spread of agriculture (seed cultivation, husbandry, plow, etc) we also see a mixture of genetic and cultural transfusion. Ditto with the horse, except much more rapidly, and horse-based technology much slower. This is partially why there's a gradient of genetic similarity across europe rather than a "european" set of genes—and with the horse technology, we have the benefit of an archeological and in certain cases textual evidence of trade between northern europe and the rest of the world.

Now, some of this is a matter of quibbling over semantics—is it displacement or is it admixture? Understandable. But the cultural diffusion in the material record is undeniable regardless of which term you pick. I'm not so sure it's worth picking a primary cause rather than accepting the inherent messiness of the archeological and genetic record where, as in the case of neanderthals, there isn't very solid evidence of infertility demonstrating firmly that the migration was mostly, if not entirely, displacement, as presumably non-hss-mixed neanderthals are extinct.

[nobody9999]

>when modern populations are so genetically diverse.

Are they? Are there any studies that confirm that hypothesis?

My understanding[0][1][2][3][4][5][6] (there are plenty more references, but I assume you get the point) is that modern human populations are incredibly similar, and not very diverse at all. In fact, all humans are more genetically similar to each other than many other species are, including chimpanzees and wheat.

[0] https://www.science.org/content/article/how-we-lost-our-dive...

[1] https://pmc.ncbi.nlm.nih.gov/articles/PMC7115999/

[2] https://www.ashg.org/wp-content/uploads/2019/09/genetic-vari...

[3] https://www.scientificamerican.com/article/humans-are-doomed...

[4] https://bigthink.com/life/humans-are-less-genetically-divers...

[5] https://www.jstor.org/stable/41466860

[6] https://www.kqed.org/quest/474/explosive-hypothesis-about-hu...

[PittleyDunkin]

> Are they? Are there any studies that confirm that hypothesis?

??? what is there to confirm? Why are you trying to spin an internal comparison as external? Indigenous populations tend to be more related to physically close indigenous populations than physically far apart indigenous populations. This is what I was referring to with the "genetic gradient". Comparing us to chimpanzees makes zero sense, let alone wheat, as we aren't trying to have sex with either, let alone "displace" them. I mean, hopefully not.

It's true that our diversity has lessened over time but this is "I don't see color" levels of delusion.

[nobody9999]

You said:

   when modern populations are so genetically diverse.

They are not. Humans as a species (in case you're not understanding what I mean by "species," I mean all the bipedal primates generally referred to as "Homo Sapiens") are not very genetically diverse.

And I provided documentation to support that assertion.

I didn't even get into the genetic evidence that variation within human population groups is greater than the variation between such groups.

That you made some sort of assumption as to the reason for my assertion, is on you and not me.

I merely pointed out that your assertion is not supported by the genetic evidence. Full stop.