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These are little bodies that provide the energy for each cell, bodies that probably originated from a once-separate bacterium, which somehow survived being engulfed by a primitive cell. They then coevolved to confer mutual advantage and developed into the mitochondria that most organisms have throughout their cells. In humans, the DNA of a mother’s mitochondria is cloned in her egg when it becomes the first cell of her child, and little or no mitochondrial DNA from the father’s sperm seems to be incorporated at fertilization. This means that mitochondrial DNA (mtDNA) essentially tracks evolution through females only (mothers to daughters), since a son’s mtDNA will not be passed on to his children. This type of DNA mutates at a much faster rate than normal (nuclear) DNA, as we will discuss in chapter 7, allowing the study of short-term evolution. Early work on human mitochondria seemed promising, showing that our species apparently had low diversity and a recent origin, but the geographic patterns seemed unclear as to where that origin might be. By 1986 I had heard through the grapevine that startling new mtDNA results were on the way to publication, and a year later they appeared in the science journal Nature , shaking up arguments about recent human evolution in such a way that things would never be the same again. This seminal publication by Rebecca Cann, Mark Stoneking, and Allan Wilson put modern human origins on the front pages of newspapers, journals, and magazines for the first time.

    Milford Wolpoff, an architect of Multiregionalism, with a Homo erectus skull from Java.
    About 150 types of mtDNA from around the world were investigated, and their variation was determined. Then a computer program was used to connect all the present-day types in an evolutionary tree, with the most economical pattern of evolutionary change (mutations), reconstructing hypothetical ancestors for the living types. In turn, the program connected those ancestors to each other, until a single hypothetical ancestor for all the modern types was created. The distribution of the ancestors implied that the single common ancestor must have lived in Africa, and the number of mutations that had accumulated from the time of the common ancestor suggested that this evolutionary process had taken about 200,000 years. This, then, was the birth of the now-famous Mitochondrial Eve, or “lucky mother,” since the common mitochondrial ancestor must necessarily have been a female. These results seemed to provide strong evidence for a Recent African Origin view for modern humans, since the research suggested that a relatively recent expansion from Africa had occurred, replacing any ancient populations living elsewhere, along with their mtDNA lineages. However, the work was soon heavily criticized. It was shown that the kind of computer program used could actually produce many thousands of trees which were all more or less as economical as the published one, and not all of these alternative trees were rooted in Africa. Moreover, other researchers criticized the calibration of the time when Mitochondrial Eve lived, while yet others questioned the constitution of the modern samples analyzed (for example, many of the “African” samples were actually from African Americans). As a result, multiregionalists were, for a while at least, able to reject these mtDNA results as irrelevant or misleading, arguing that fossil evidence (and their interpretation of it) remained the only valid approach to reconstructing recent human evolution.
    However, the results strongly supported the Recent African Origin view that people like Günter Bräuer (from Hamburg) and I had been developing from the fossils. Günter was less inclined to view Homo sapiens as a newly evolved species, and more inclined to think that hybridization had occurred with people like the Neanderthals, following the dispersal from Africa, but we both welcomed the new mtDNA