In several threads on this board, about the Church’s teaching on monogeny and the descent of modern humans from a literal Adam and Eve, I have pointed out the scientific difficulties with holding to the teaching as set out in Humani Generis. Several scientific lines of evidence show that modern humanity did not have a single pair of ancestors, at least in the 6 million years since the lineages leading to modern humans diverged from the lineage leading to chimpanzees. The Church’s teaching on monogeny is untenable.
However, in putting forward those arguments, a couple of people discussing the subject with me raised the question of Mitochondrial Eve (or the Most Recent Common Ancestor in the maternal line). There are many reasons why it does not make sense to identify the maternal MRCA with the biblical Eve. One of those arguments that I used was that the date of Mitochondrial Eve (approximately 175,000 years BP) pre-dated the emergence of anatomically modern humans at about 130,000 to 140,000 years BP. It is difficult to identify biblical Eve with a being who pre-dated the emergence of modern humans in the archaeological record. As of Thursday, I can no longer make that argument – a paper by McDougall et al that puts a new date on the OMO I and OMO II specimens (which are considered to represent anatomically modern humans and to belong to the species Homo sapiens) from the Kibish formation in Ethiopia. For many years the accepted date for those specimens was 130,000 years BP. Well, on Thursday, in Nature 433, 733 - 736 (2005), McDougall et al get a new age for these specimens by analysis of the sapropels (organically loaded muds) in the deposits and Ar40/Ar39 dating of feldspars from tuffs in the formation. The new age is 195kyr +/- 5kyr which is much earlier than previously thought and before the estimated date of Mitochondrial Eve. It pushes back the emergence of anatomically modern humans by at least 40,000 years. There are still many and totally compelling reasons for not identifying Mitochondrial Eve with biblical Eve and indeed for rejecting the concept of a biblical Eve at all, but I can no longer use the argument that Mitochondrial Eve pre-dates the emergence of anatomically modern humans, and so I must retract that particular argument, noting that that doesd not invalidate my overall position. Alec