Bear Ribs
Well-known member
That's not actually how that works, Y-Chromosomal Adam (Y-MRCA) was not the only man on earth at the time of his life. Each time a basal haplogroup ends a generation without any sons, the person we reference as Y-MRCA ratchets forward a bit because a new person is now the most recent common ancestor of all current surviving humans (the previous oldest ancestor no longer counting as there's a new youngest common ancestor. However, Y-MRCA was not living at a point where there was only one surviving human male, merely that's the one who still has an unbroken genetic heritage of son of- son of- son of- throughout history with no generation of only daughters in between.I can't prove that we've survivred either but the Y chromosome and MtDNA we have came from just one man and one woman from so long ago that Adam and Eve weren't alive at the same time and may have been pre-human apes.
Mitochondrial Eve is exactly the same, each time a haplogroup has no daughters the estimated age of mt-MRCA ratchets forward, but mt-MRCA was not the only woman alive, nor the oldest woman, nor the beginning of a new species, she's merely the most recent human who we can trace daughter of- daughter of- daughter of- through with no generation having only sons along the way.