【進化】旧石器時代のアフリカへの逆移動

The mitochondrial genome (mitogenome) of a 35,000-year-old Homo sapiens found in the Pestera Muierii cave of Romania is presented in a paper in Scientific Reports. The study suggests that this human (PM1) belongs to a genetic population who share a common ancestor (haplogroup) called U6 basal*, which has not previously been identified in any ancient or present-day humans. The findings support the hypothesis of an Early Upper Palaeolithic (starting approximately 45,000 years ago) migration back to North Africa from Western Asia.

Analyses of present-day human mitogenomes suggest that, in conjunction with the Eurasian expansion approximately 45,000 - 40,000 years ago, some populations initiated a migration back to North Africa. However, the scarcity of remains in North Africa has prevented researchers from obtaining direct evidence of such a migratory phenomenon during the Palaeolithic period.

By extracting DNA from two of the teeth of PM1, Concepcion de-la-Rua and colleagues analysed and sequenced the mitogenome. The authors propose that the newly identified U6 basal* haplogroup has a Eurasian origin, from which haplotypes predominantly found in present-day North-Western African populations are derived. The authors suggest that the PM1 lineage may have been an offshoot to South-East Europe during the Early Upper Palaeolithic migration from Western Asia to Africa.