A new paper, The Dawn of Human Matrilineal Diversity, is out in AJHG. I read too much John Hawks to really be all that excited about mtDNA based studies, and this paper is Mitochondrial Eve to the nth power. But…I do think it is indicative of a trend which suggests a rollback from the most extreme Out of Africa scenarios; i.e., that one band somewhere in Eastern Africa arose ~100,000 years ago and expanded demographically so that they were the exclusive ancestors of all human beings.1 The introgression story is one angle; but the likelihood of preexistent population substructure within Africa itself is another. If you don’t read the paper (which is Open Access), just check out Figure 1 and the map. Breathless description of the study over at ScienceDaily of course….
Related: Kambiz comments in more detail.
1 – Some of this was more about public perception than reality; just like the one mtDNA ancestor was conflated with one female ancestor (the same trick of course applied to the NRY).