Stranger things have happened--Evidence for Eve...and the commonality of human DNANoah is also the second time that all humanity was born of sisters and brothers repeatedly reproducing. Things have changed, as today that would be genetically catastrophic, even impossible.
Eve Gene: Do We All Descend From a Common Female Ancestor?
According to DNA research, we may all have a common ancestor, an African woman who lived thousands of years ago. How did scientists reach this conclusion? Is it even possible?
science.howstuffworks.com
In 1987, a group of geneticists published a surprising study in the journal Nature. The researchers examined the mitochondrial DNA (mtDNA) taken from 147 people across all of today's major racial groups. These researchers found that the lineage of all people alive today falls on one of two branches in humanity's family tree. One of these branches consists of nothing but African lineage, the other contains all other groups, including some African lineage.
Even more impressive, the geneticists concluded that every person on Earth right now can trace his or her lineage back to a single common female ancestor who lived around 200,000 years ago. Because one entire branch of human lineage is of African origin and the other contains African lineage as well, the study's authors concluded Africa is the place where this woman lived. The scientists named this common female ancestor Mitochondrial Eve.