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View Full Version : Admixture into and within SSA-Busby et al



Angela
23-06-16, 23:16
This is a continuation, in a way, of the other Busby papers on recent admixture.

See:
https://elifesciences.org/content/5/e15266

"Similarity between two individuals in the combination of genetic markers along their chromosomes indicates shared ancestry and can be used to identify historical connections between different population groups due to admixture. We use a genome-wide, haplotype-based, analysis to characterise the structure of genetic diversity and gene-flow in a collection of 48 sub-Saharan African groups. We show that coastal populations experienced an influx of Eurasian haplotypes over the last 7000 years, and that Eastern and Southern Niger-Congo speaking groups share ancestry with Central West Africans as a result of recent population expansions. In fact, most sub-Saharan populations share ancestry with groups from outside of their current geographic region as a result of gene-flow within the last 4000 years. Our in-depth analysis provides insight into haplotype sharing across different ethno-linguistic groups and the recent movement of alleles into new environments, both of which are relevant to studies of genetic epidemiology."

So far so good.

However, look at these graphics...

The track of the Bantu expansion makes sense. So does the CEU into South Africa because we know of historical era migrations into that region. However, the West Eurasian in East Africa is the result of a TSI or TSI like migration from northern Africa into East Africa? How did Florentines manage that? Plus, we have ancient genome analysis in Lazaridis et al 2016 which tells us it was a Levantine Neolithic like population which is responsible for the admixture. So, whatever looks like TSI must actually be a mix of various admixtures of which Levantine Neolithic must be one.

I haven't read the paper and supplements carefully, so I may change my mind, but right now this doesn't make a lot of sense.
https://sangerinstitute.files.wordpress.com/2016/06/africaadmixtureeventsmapeurasiabantu_840-mid-text.jpg?w=551

LeBrok
24-06-16, 03:35
I agree. Plus the mysterious R1b influx. I'm guessing Chalcolithic/Bronze Age migration.