An age of ~60 ky indicates that haplogroup U arose very soon after the "out of Africa" exit. As for U5, its sequence divergence was 8.1 ± 1.8 substitutions, corresponding to 41.4 ± 9.2 ky, a time estimate in full agreement with its proposed proto-European origin (Richards et al. 2000). It is striking that the sequence divergence of U5b1b, the subclade encompassing mtDNAs from the Saami, Yakut, Berbers, and Fulbe, was 1.7 ± 0.5 substitutions, thus corresponding to only 8.6 ± 2.4 ky.
Am. J. Hum. Genet. (Online Early)
Saami and BerbersAn Unexpected Mitochondrial DNA Link
Alessandro Achilli et al.
The sequencing of entire human mitochondrial DNAs belonging to haplogroup U reveals that this clade arose shortly after the "out of Africa" exit and rapidly radiated into numerous regionally distinct subclades. Intriguingly, the Saami of Scandinavia and the Berbers of North Africa were found to share an extremely young branch, aged merely 9,000 years. This unexpected finding not only confirms that the Franco-Cantabrian refuge area of southwestern Europe was the source of late-glacial expansions of hunter-gatherers that repopulated northern Europe after the Last Glacial Maximum but also reveals a direct maternal link between those European hunter-gatherer populations and the Berbers.