July 21, 2010

Internal diversification of mtDNA haplogroup R0a

Molecular Biology and Evolution, doi:10.1093/molbev/msq178

Internal diversification of mitochondrial haplogroup R0a reveals post-Last Glacial Maximum demographic expansions in South Arabia

Viktor Černý et al.

Abstract

Widespread interest in the first successful Out of Africa dispersal of modern humans 60 – 80 KYA via a southern migration route has overshadowed the study of later periods of South Arabian prehistory. In this work we show that the post-Last Glacial Maximum period of the past 20,000 years, during which climatic conditions were becoming more hospitable, has been a significant time in the formation of the extant genetic composition and population structure of this region. This conclusion is supported by the internal diversification displayed in the highly resolved phylogenetic tree of 89 whole mitochondrial genomes (71 being newly presented here) for haplogroup R0a – the most frequent and widespread haplogroup in Arabia. Additionally, two geographically specific clades (R0a1a1a and R0a2f1) have been identified in non-Arabic speaking peoples such as the Soqotri and Mahri living in the southern part of the Arabian Peninsula where a past refugium was identified by independent archaeological studies. Estimates of time to the most recent common ancestor of these lineages match the earliest archaeological evidence for seafaring activity in the peninsula in the sixth millennium BC.

Link

4 comments:

terryt said...

"Estimates of time to the most recent common ancestor of these lineages match the earliest archaeological evidence for seafaring activity in the peninsula in the sixth millennium BC".

Very interesting. Take note, Maju, 'earliest archaeological evidence for seafaring activity in the peninsula in the sixth millennium BC'. And although:

"Widespread interest in the first successful Out of Africa dispersal of modern humans 60 – 80 KYA via a southern migration route has overshadowed the study of later periods of South Arabian prehistory"

R0a is not part of that migration. It's arrival is later. So what are the remnant haplogroups of this 'southern migration route' in Southern Arabia? Surely if the region has been so inviting all that time some of the original ones should survive.

eurologist said...

Why are you concentrating on that particular estimate in this paper, when others (as expected based on climate) go to before 20,000 years ago?

terryt said...

"Why are you concentrating on that particular estimate in this paper, when others (as expected based on climate) go to before 20,000 years ago?"

The subject of comments here is surely the paper presented here. The authors presumably are aware of other estimates of 20,000 years yet choose to ignore them, for some reason. I'll leave you to suggest one. And what has climate to do with the time for the most recent common ancestor in the region? The authors seem to suggest that sea-faring was the deciding factoe in their arrival.

mutargim73 said...

'Earliest archaeological evidence for seafaring activity' in Socotra goes down to 1.4 min. BC at least - with Oldowan stone tools discovery on Socotra in 2008