What are Y-Chromosomal Adam and Mitochondrial Eve?

Response

“Y-Chromosomal Adam” and “Mitochondrial Eve” are scientifically proven theories indicating that every living man today is descended from a single man, and every living man and woman today is descended from a single woman.

Humans possess 23 pairs of chromosomes. Among these pairs, known as sex chromosomes because they determine gender, females have two X chromosomes, while males have one X chromosome and one Y chromosome. Girls inherit one X chromosome from their mother and the other from their father. Boys, on the other hand, receive the X chromosome from their mother and the Y chromosome from their father. Consequently, the Y chromosome is directly passed from father to son, enabling scientists to trace male lineage.

In 1995, the journal Science published the findings of a study that analyzed a segment of the human Y chromosome from 38 men of various ethnic backgrounds for variations (Dorit, R:L:, Akashi, H: and Gilbert, W: 1995: “Absence of polymorphism at the ZFY locus on the human Y chromosome:” Science 268:1183-1185). This segment of the Y chromosome comprised 729 base pairs. Surprisingly, the researchers discovered no variations at all. Their conclusion was that the human population must have undergone a genetic bottleneck at some point in the recent past. Subsequent research revealed that every living man today is actually descended from a single man now known as “Y-Chromosomal Adam.”

Mitochondrial Eve takes this concept further. While Y chromosomes are exclusively inherited from father to son, mitochondrial DNA is inherited from the mother to both daughters and sons. Since mitochondrial DNA is solely transmitted by the mother, and it is not influenced by the father, it allows researchers to trace maternal ancestry.Ever the father, mitochondrial-DNA lineage is the same as the maternal lineage. Knowing this, scientists have discovered that every human alive today can trace their ancestry back to a single woman whom they now refer to as “Mitochondrial Eve.” While Y-Chromosomal Adam is believed to be the ancestor of every living man, Mitochondrial Eve is believed to be the mother of all living humans, both male and female.

It is important to note that this does not prove that Y-Chromosomal Adam was the only man alive before he started having children. This only proves that his descendants are the only ones to have survived. Likewise, Mitochondrial Eve was not necessarily the only woman alive before having children. Rather, all we know for sure is that she is at least one of the ancestors of all living humans. While contemporaries of hers may or may not factor into the ancestry of living humans, we can at least say that none of their mitochondrial-DNA has survived.

Scientists who share the Darwinian bias naturally presume that these two were not the only humans alive during their pre-childbearing lifetimes, while biblical creationists naturally presume that they were. As for determining when these two actually lived respectively, the conventional perspective is founded upon uniformitarian assumptions which many creationists reject, and with fair reason. So there is disagreement there, too. Naturally, the Darwinian timeframe is much longer (tens to hundreds of thousands of years), presuming an Old-Earth scenario, while the Young-Earth perspective is much shorter (less than ten thousand years). What we can say with fair certainty is that, regardless of time frames and alleged contemporaries, every man alive today descended from one man while every human alive today descended from one woman.

“Adam named his wife Eve, because she would become the mother of all the living” «And Adam called his wife’s name Eve; because she was the mother of all living. », (Genesis 3:20 NIV).