In this communication, we present a study of the human mitochondrial haplogroup L1c which has been carried out on a total of 455 individuals from 27 African and American populations using both hypervariable regions 1 and 2. The results obtained lead us to draw three main conclusions. First, the time to the L1c most recent common ancestor (TMRCA) has been estimated as 90,000 ± 13,000 YBP, substantially older than the previous estimate (59,650 ± 11,800) and in agreement with archaeological dating. Second, we observed that L1c frequencies reach very high values in Western Pygmies populations (from 86% to 98%), hunter-gatherers supposed to be the most ancient inhabitants of this area. Third and finally, the median networks built using our dataset change the phylogeny of the entire haplogroup. In fact, we present a substantially modified structure for the sub-haplogroups L1c1 and L1c3 and identify a new clade, L1c4 which contains mostly sequences from Pygmies.
Taking into consideration the L1c phylogeographic features together with archaeological knowledge, we propose that the hunter-gatherers communities living in Central Africa at least 40,000 YBP could be the ancestors of both Bantu and Western Pygmy populations. These two groups could have separated later on, because of the cycles of expansion and fragmentation of the forest environment occurred till 12,000 YBP. As the next step of this research, we will sequence the complete mtDNA genome in order to test the robustness of the new phylogeny.
Nice to see an older date for this.