Mary Katherine Gonder*, Holly M. Mortensen*, Floyd A. Reed*, Alexandra de Sousa, and Sarah A. Tishkoff*
Studies of human mitochondrial (mt) DNA genomes demonstrate that the root of the human phylogenetic tree occurs in Africa. Although 2 mtDNA lineages with an African origin (haplogroups M and N) were the progenitors of all non-African haplogroups, macrohaplogroup L (including haplogroups L0–L6) is limited to sub-Saharan Africa. Several L haplogroup lineages occur most frequently in eastern Africa (e.g., L0a, L0f, L5, and L3g), but some are specific to certain ethnic groups, such as haplogroup lineages L0d and L0k that previously have been found nearly exclusively among southern African “click” speakers. Few studies have included multiple mtDNA genome samples belonging to haplogroups that occur in eastern and southern Africa but are rare or absent elsewhere. This lack of sampling in eastern Africa makes it difficult to infer relationships among mtDNA haplogroups or to examine events that occurred early in human history. We sequenced 62 complete mtDNA genomes of ethnically diverse Tanzanians, southern African Khoisan speakers, and Bakola Pygmies and compared them with a global pool of 226 mtDNA genomes. From these, we infer phylogenetic relationships amongst mtDNA haplogroups and estimate the time to most recent common ancestor (TMRCA) for haplogroup lineages. These data suggest that Tanzanians have high genetic diversity and possess ancient mtDNA haplogroups, some of which are either rare (L0d and L5) or absent (L0f) in other regions of Africa. We propose that a large and diverse human population has persisted in eastern Africa and that eastern Africa may have been an ancient source of dispersion of modern humans both within and outside of Africa.
Firstly, I feel obliged to point out that M and N both have a Eurasian origin. Okay, so the origin of M was up for a debate a while ago, but I’ve never seen N down as African in origin. Where did that come from? This is contradicted in the full text:
For example, mtDNAs of Tanzanians belonging to haplogroup M1 cluster with peoples from Oceania, whereas Tanzanian mtDNAs belonging to haplogroup N1 and J cluster with peoples of Middle Eastern and Eurasian origin. However, the presence of haplogroups N1 and J in Tanzania suggest “back” migration from the Middle East or Eurasia into eastern Africa, which has been inferred from previous studies of other populations in eastern Africa (Kivisild et al. 2004).
I’m trying to figure out if there was a migration South from east Africa that might explain the Hofmeyr skull. Anyone with any thoughts on this, let me know.