Did ‘Adam’ Meet ‘Eve’?

They lived around the same time but they probably didn’t live near each other, let alone mate

According to researchers, modern humans trace their lineage to two common ancestors. Two individuals, ‘Mitochondrial Eve’ and ‘Y-chromosomal Adam’, are believed to have passed down portions of their genomes to present day humans. Previous research has shown that Mitochondrial Eve, or the matrilineal most recent common ancestor, is likely to have emerged from East Africa somewhere around 99,000 and 148,000 years ago. But apart from this, very little is known about human ancestors.

Now a new study, in the journal Science, shows that the male most recent common ancestor, or Y-chromosomal Adam, lived roughly around the same time as Mitochondrial Eve. The recent study, which was conducted by sequencing the DNA of many entire Y chromosomes, found that the male most recent common ancestor lived around 135,000 years ago. The researchers claim that ancient ‘Adam’ and ancient ‘Eve’ probably didn’t even live near each other, let alone mate.

The date of origin of ‘Mitochondrial Eve’ had been found by studying the DNA of mitochrondria, which are structures inside cells. Mitochondrial DNA is present in the human egg, so only women pass it on to their children. This can reveal the maternal lineage to an ancient Eve. The Y chromosome, on the other hand, is passed down from father to son. For the current research, the Y chromosomes of 69 men in several populations in sub-Saharan Africa and Siberia, Cambodia, Pakistan, Algeria and Mexico were studied.

The new study shows that Y-chromosomal Adam predates the earliest known fossil of Homo sapiens. This may imply that H sapiens is older than what the fossil evidence currently suggests or that early humans mated with a closely related hominid species that contributed to the Y chromosome gene pool.

According to the researchers, the human genome contains tiny snippets of DNA from many other ancestors. These however don’t show up in mitochondrial or Y-chromosome DNA. The researchers are currently sequencing the Y chromosomes of nearly 2,000 other men. This new research, the scientists believe, will help them pinpoint where precisely in Africa our ancestors lived.

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