- Rh Negative Facts
October 27, 20200
Archaeological discoveries of burial sites with female warriors on the Eurasian Steppes suggest that the Scythian women may have inspired the Amazon myth. In 2019 a grave with multiple generations of female Scythian warriors in golden headdresses was found near Russia’s Voronezh.
In 2017, a genetic study of the Scythians suggested that the Scythians were ultimately descended from the Yamna culture, and emerged on the Pontic steppe independently of peoples belonging to Scythian cultures further east. Based on the analysis of mithocondrial lineages, another later 2017 study suggested that the Scythians were directly descended from the Srubnaya culture. A later analysis of paternal lineages, published in 2018, found significant genetic differences between the Srubnaya and the Scythians, suggesting that the Srubnaya and the Scythians instead traced a common origin in the Yamnaya culture, with the Scythians and related peoples such as the Sarmatians perhaps tracing their origin to the eastern Pontic-Caspian steppes and the southern Urals. Another 2019 study also concluded that migrations must have played a part in the emergence of the Scythians as the dominant power of the Pontic steppe.
So what does that have to do with Rh negative people and blood?
According to Blood groups in ancient Europe by Iain Mathieson:
“I looked at these alleles in ancient samples dating to the past 12,000 years, all from West Eurasia. I divided them into four groups:
- Hunter-gatherers (HG); Mesolithic and neolithic individuals with ancestry that is like that of Mesolithic Europeans.
- Early Farmers (EF); Neolithic individuals from NW Anatolia, and European Neolithic individuals with similar ancestry, plus small (~0-20%) amounts of hunter-gatherer ancestry.
- Steppe (ST); Bronze Age individuals with “Yamnaya-like” ancestry
- Bronze Age (BA); Individuals from Bronze Age Europe that have a mixture of the three other types of ancient ancestry.
I also compared with present-day European populations, separating out Finns (FIN) and Non-Finns (NFE) (Finns have more steppe-like ancestry).
The ABO determining variants are on the 1240k capture array that has been used to genotype many samples, so I was able to look them up in a sample of around ~500 ancient individuals (the same individuals used here). I looked up present-day allele frequencies in gnomAD. It’s harder to genotype the RHD deletion from capture data so I used a smaller dataset of around ~200 individuals with published shotgun data to genotype this deletion. I couldn’t find it in gnomAD so I used allele frequencies from 1000 Genomes.
It turns out that the O allele is at high frequency in hunter-gatherers, but relatively rare on the Steppe. The B allele seems to be absent in both hunter-gatherers and early farmers, and seems to be introduced from the steppe in the Bronze Age. The Rh- allele seems to be relatively common in hunter-gatherers and, particularly, in steppe populations, and relatively rare in early farmers, partly confirming Haldane and Cavalli-Sforza’s hypotheses. Allele frequency estimates are in the figures below (bars show 95% binomial confidence intervals).
If we compute expected phenotypic frequencies, this suggests that around around 65% of Mesolithic hunter-gatherers would have been type O, compared to around 40% in present-day Europeans, and around 40% of Steppe-ancestry individuals would have been Rh-, compared to around 24% of hunter-gatherers, 4% of early farmers, and about 16% of present-day Europeans.
Broadly speaking, the present-day frequencies are consistent with genome-wide ancestry, in the sense that they are just a mixture of the ancient populations (roughly equal to the Bronze Age). The Rh- frequency in present-day Europe is a bit lower than in the Bronze Age, which might be evidence for selection against the allele, but might also just be because there’s a bit less Steppe ancestry in 1000 Genomes than in the samples Bronze Age populations. This doesn’t really explain the Basque frequency though. The Basque population doesn’t particularly have a lot of hunter-gatherer or Steppe ancestry. But perhaps there is substructure in Rh- frequencies within the Basque population, or within the hunter-gatherer populations. Finally, we’ve explained the present-day frequency in terms of mixtures of ancestral populations, but really we have just pushed the question back ten thousand years. Why was the Rh- frequency so high in hunter-gatherer and Steppe populations? Clearly there has to be some selective advantage to this allele at some point, otherwise it would just have been removed everywhere. Perhaps in these populations that selective advantage was stronger. Or perhaps they were just sufficiently small that it was able to drift to high frequency.”
Blood groups in ancient Europe
Blood groups in ancient Europe 21 September 2017 Human blood groups are interesting from both medical and evolutionary perspectives. Different blood groups confer resistance or susceptibility to a wide range of infectious disease and, likely as a result of this, have been under long-term balancing selection across primates. They also vary dramatically in frequency across human populations and, probably, across time as well. Here, we use ancient DNA to estimate the frequencies of the two most commonly discussed groups – specifically the ABO and Rhesus systems – in Europe over the past ten thousand years. We show that some ancient populations of Europe had blood group frequencies that were more extreme than any present-day population. In particular, Mesolithic hunter-gatherers had a higher frequency … Continue reading
Thanks to: https://www.rhesusnegative.net