Adam and Eve

dreamstime_s_35121468The closest living relatives to humans are baboons, chimpanzees and gorillas. The similarities between their DNA sequencing and our human genome is 95 to 99%. By using a technique called the molecular clock which estimates the time required for the number of mutations to accumulate between two lineages, the approximate time for the split can be calculated.

Each time a certain mutation appears in an individual and is passed on to his or her descendants a hoplagroup is formed including all of the descendants of the individual who will also carry that mutation. By comparing mitochondrial DNA which is inherited only from the mother, geneticists have concluded that the last common female ancestor whose genetic marker is found in all modern humans, the so-called mitochondrial Eve, must have lived around 200.000 years ago.

The out of Africa model proposes that modern Homo sapiens originated in Africa and migrated to Eurasia resulting in complete replacement of other Homo species. Analysis is consistent with the idea that Africa is the ancestral home of “the mitochondrial Eve and Y-chromosome Adam”

The theory predicts that all mitochondrial genomes today should be traceable to a single woman, the “mitochondrial Eve”, whereas the Y chromosome is passed from father to son only, mitochondrial DNA (eDNA) is passed from mother to daughter and son.

These primeval people are not parallel to the biblical Adam and Eve. They were not the first modern humans on the planet, but instead just two out of thousands of people alive at the time with unbroken male or female lineages that continue on today.  Read more…