Adam and Eve DID live in Africa at the same time - but they probably didn't know each other

By Ellie Zolfagharifard

Adam and Eve lived in Africa at the same time - but probably never met, scientists claim. It was previously believed that ‘Y-chromosomal Adam’ and ‘Mitochondrial Eve’ - the most recent common ancestors to males and females - lived at completely different times. But a new study of 69 men from around the world found ‘Y-chromosomal Adam’ walked the Earth between 120,000 and 156,000 years ago, much earlier than previously believed. 

A new study of 69 men from around the world found 'Y-chromosomal Adam' walked the Earth between 120,000 and 156,000 years ago, much earlier than previously believed. It places him nearer to Eve who was around 99,000 to 148,000 years ago the analysis found. It places him nearer to Eve who was around 99,000 to 148,000 years ago the analysis found. But the researchers say it is ‘extremely unlikely’ they were exact contemporaries.Initial estimates for the male MRCA ranged from between 50,000 to 115,000 years ago. Geneticist Professor Carlos Bustamante, of Stanford University, California, said: 'Previous research has indicated the male most recent common ancestor (MRCA) lived much more recently than the female MRCA. But now our research shows there is no discrepancy.'

Mitochondrial Eve and Y-chromosomal Adam are the two individuals who passed down a portion of their genomes to the vast expanse of humanity. But many aspects of their existence, including when they lived, are shrouded in mystery. The researchers compared Y-chromosome variations among participants from nine globally distinct areas, including some that have only recently been available, such as Namibia, the Democratic Republic of Congo, Gabon, Algeria, Pakistan, Cambodia, Siberia and Mexico.

Mitochondrial Eve and Y-chromosomal Adam are the two individuals who passed down a portion of their genomes to the vast expanse of humanity. But many aspects of their existence, including when they lived, are shrouded in mystery 

The study obtained results for 10 million nucleotides, biological molecules that form the building blocks of the Y chromosome, for each individual. The annual mutation rate was then estimated by comparing it with a known event, the human settlement of the Americas about 15,000 years ago.But despite the Adam and Eve monikers, which evoke a single couple whose children peopled the world, they were not the only man and woman alive at the time, or the only ones to have present day descendants.They simply had the good fortune to successfully pass on the Y chromosome and the mitochondrial genome across thousands of years to most of us. Powerful, state of the art microscopes allowed the identification of about 11,000 mutations, enabling the researchers to establish genetic links and timelines with unprecedented accuracy. The study obtained results for 10 million nucleotides, biological molecules that form the building blocks of the Y chromosome, for each individual. The annual mutation rate was then estimated by comparing it with a known event, the human settlement of the Americas about 15,000 years ago.

The tree, published in Science, also exemplifies the extraordinary depth of genetic diversity present among modern Africans. But it is also possible it represents a time when only a few sequences were passed on and many died out due to an external event that has not yet been identified. They repeated the analysis with the individuals’ mitochondrial DNA to generate the two estimates for Adam and Eve, showing for the first time they overlap. Professor Bustamante said: ‘We can now date certain events very precisely. We found a single variant that shows how three ancient lineages came together about 48,000 years ago, plus or minus only a couple of hundred years. The accuracy is exquisite.’The tree, published in Science, also exemplifies the extraordinary depth of genetic diversity present among modern Africans. But it is also possible it represents a time when only a few sequences were passed on and many died out due to an external event that has not yet been identified. ‘For the most part, it is a random process. Some lineages die out, some are successful,’ said David Poznik, a graduate student in Prof Bustamante’s lab. ‘But it is also possible there may be elements of human demographic history that predispose these lineages to coalesce at certain times.’