Question

In 1987 a group of molecular geneticists at the University of California at Berkeley offered support for the idea that modern humans (AMHs) arose fairly recently in Africa, then spread out and colonized the world. The geneticists analyzed genetic markers in placentas donated by 147 women whose ancestors came from Africa, Europe, the Middle East, Asia, New Guinea, and Australia. By estimating the number of mutations that had taken place in the mithochondrial DNA (mtDNA) of each of these samples, the researchers concluded that

A. everyone alive today has mtDNA that descends from a woman (dubbed Eve) who
B. everyone alive today has mtDNA that descends from a woman (dubbed Eve) who
C. establishing a "genetic clock" to model human evolution is reliable only when lived in sub-Saharan Africa around 200,000 years ago and that her descendants left Africa no more than 135,000 years ago. lived in Asia around 50,000 years ago and that her descendants left Asia 100,000 years ago. focusing on 50,000 years into the past.
D. everyone alive counts Neanderthals of western Europe as their ancestor. E. Neanderthals coexisted with modern humans in the Middle East for at least 2,000 years

Answer 1

A) everyone alive today has mtDNA that descends from a woman (dubbed Eve) who lived in sub-Saharan Africa around 200,000 years ago and that her descendants left Africa no more than 135,000 years ago.

Step-by-step explanation:

The group of geneticists whose conclusion was also corroborated by the research of Professor Rebecca L. Cann studied the mitochondrial DNA variation and evolution in humans, popularly called Mitochondrial Eve and discovered that all living humans are genetically descended from a single African mother who lived above 200,000 years ago. This discovery over the years has become the most widely accepted explanation of the origin of all modern humans.

Cann laid the experimental groundwork for the concept of Mitochondrial Eve, and consequently the Out of Africa theory. From late 1970s she had collected mtDNA samples from women of different ethnic backgrounds, such as from Asia, South Pacific, Europe and Americans of African descent. She used the data in her PhD thesis in 1982. A collective paper was published on this work in 1987.