The Mitochondrial Eve Theory states that the mitochondrial DNA (mtDNA) in all humans is inherited from one common ancestor in Africa approximately 200,000 years ago. In my opinion, the mtDNA in all humans can be traced back to a common ancestor, but it is not necessarily the first common ancestor of all modern humans.

Mitochondrial DNA is the tool, which is used to support the idea of the Mitochondrial Eve theory. Mitochondria are organelles that provide cells with a form of stored chemical energy. In a human egg there are 100,000 mtDNA, but in a sperm cell there are less than 100. Soon after conception, the sperm’s mtDNA is destroyed because it is seen as a foreign substance inside the embryo. Only the mother’s mtDNA remains, and therefore men cannot pass on their mtDNA. The mtDNA is almost an exact copy of the mother’s, however, some mutations occur to make the offspring’s mtDNA their own. With the assumption that the mutations are constant, the mtDNA can provide a “molecular clock” with which to count backwards through generations to reveal the first common ancestor of all modern humans.

Since the late 1980’s when the theory was first proposed, it has caused a lot of controversy. Some people may have considered the “Eve” was scientific proof that Adam and Eve existed. In the past there have been feuds between religious and scientific groups, concerning the theory of evolution and the creation stories of various religions. This theory may have also led to further denial of evolution for some people. But the controversy does not just lie between science and religion, but also within the science itself. Some people do not believe that the mutations of mtDNA are constant with each generation, which would make the “Eve” calculations inaccurate. Others are still not convinced that at conception, the sperm’s mtDNA is not entirely destroyed and therefore the embryo’s mtDNA is a combination of its parent’s mtDNA. With so many differing opinions and still some unanswered questions concerning this idea, leaves it as just one possibility, or theory.

The supposed “Evolutionary Eve” may not be the first and only common ancestor of all modern humans. We must take in to account why there happened to only be one line of mtDNA when “Eve” was living. 200,000 years ago a natural disaster, rapid climatic changes, or a disease could have occurred, causing a major population decrease in human life. This would have resulted in a loss of different mtDNA family lines. The remaining population may not have had daughters or children to carry on mtDNA of their family. This might leave only one mtDNA family line. And the eldest traceable female member of this family could now be considered as our common ancestor, or “Evolutionary Eve”. But this woman would not be the first common ancestor, because there had to have been more women and other mtDNA family lines whom she was related to, who existed before her. We call her the first common ancestor because we cannot trace the other humans living before her as we can ourselves to find a common ancestor. Thus, the “Evolutionary Eve” may not be the first ancestor of all humans.

The logic used to count backwards to the first common ancestor is flawed. Due to population fluctuations, future generations could possibly date the first common ancestor back to our time with the logic used in the Mitochondrial Eve theory. If something were to drastically downsize the population of humans at this point in time, such as a nuclear or biological war, a large number of mtDNA lines would be lost. Some of the remaining mtDNA family lines may be destroyed due to a lack of daughters or children, and may ultimately result in only one mtDNA family line, once again. 200,000 years from now, the descendants of that mtDNA family line may trace it back to the eldest female family member with that mtDNA, and call her the first common ancestor or the “Evolutionary Eve”. But we know that woman is not the first common ancestor because other women and men with different and related mtDNA family lines existed before her. Therefore the Mitochondrial Eve theory does not prove that this common ancestor is the first, but more accurately the most recent common ancestor of modern humans.

The “Evolutionary Eve” is wrongly named, as “Eve” suggests that she was the first human, or first common ancestor of all humans. The fact that only one mtDNA family line existed while “Eve” was living, does not mean she was the first or only female human at the time. There had to have been more generations of different and related mtDNA family lines before and while she was living. However, the carriers of the different mtDNA lines did not have children or daughters, leaving “Eve” as the carrier of a mtDNA family line that was successful in having daughters who would pass on their mtDNA to their children. Therefore the Mitochondrial Eve theory does produce a fairly accurate way of tracing human ancestry to a common relative, but does not by any means find the first female, or modern human.