The Emergence of Anatomically Modern Humans Essay

The Emergence of Anatomically Modern Humans - Essay Example It remained a hypothesis until in 1980s when scientific proof of linkages between mitochondrial DNA and samples taken from fossilized specimens were seen to match. Darwin suggested this model after studying the behavior of African apes at the London zoo. He postulated that all Homo sapiens can trace their roots to east Africa from where they originated and moved to other parts of the world. This was termed as ‘monogenism’ or single origin. It was not until the 1980s that a scientist named Allan Wilson and his team was able to find substantial proof of this by comparing the mitochondrial DNA of humans to that of chimpanzees. He concluded that the uncanny resemblance and scarce diversity between the two samples of mitochondrial DNA strongly suggests an evolutionary link between the two. Keeping in mind the limited resources of that time, scientists were able to conclude in 1990s that this evolution probably took place about 150,000 years ago in East Africa. Another important step in proving this theory to be accurate was the use of Y- chromosome that showed its first signs of diversity after the first migration from Africa. It is important to understand that the reason why only mitochondrial DNA and Y-chromosome were chosen to conduct this genomic reconstruction was because the mitochondrial DNA is passed from the mother to the child without any mutations so that it is safe to say that the mitochondrial DNA that we possess is very much like the mitochondrial DNA of Eve (Jones & John, 2007). Similarly, the Y-chromosome in every adult male shows the least degree of mutation and is very similar to that of Adam himself. Therefore, the tracing of human evolution is most accurate when these two chromosomes are used for genetic reconstruction of ancient Homo sapiens. The second part of this theory discusses how the Homo sapiens travelled out of Africa and expanded to other parts of the world.