One Page Response

One Page Response

            From the “Journey of Man” video and reading, I learned that the ancestor of human beings originated from Africa. They migrated over time and populated the world. The process of migration is extremely slow. Rather than migration, it is more like some of the ancestor population moved a few miles away from the others in order to have more space and food sources. After millions of years, generations of ancestors kept moving away from each other, and they eventually reached all parts of the world. How can we prove that all human beings around the world originated from Africa? By comparing the mtDNA and Y chromosomes of human beings all over the world, scientists trace the similarities and find out that all females have one ancestor and all males have one ancestor. As a result, the origin for human can be traced back to Africa. For my assigned reading, I read “Founder Mutation”. The term referred to a genetic legacy of a common ancestor that can lead its offspring to disease. If a person receives a certain founder mutation gene one side of his parents, he would not get the disease. Instead, he would be a carrier, and being a carrier of founder mutations can prevent him from getting certain kinds of disease. However, if a person receives a certain founder mutation gene from each of his parent, he will catch the disease and will probably die before reproduction. As a result, those who carry a pair of founder mutation genes will die out, and those who carry only one founder mutation gene will benefit from the gene and will pass it to their offspring and control the proportion of the founder mutation gene in a population. I think this is the reason why close relative cannot marry each other. If they do, there will be more chances that their offspring will carry a pair of founder mutation genes and die of disease. Furthermore, it will throw off the founder mutation gene proportion balance in the population.

            The founder mutation gene shortens after each generation because clean genes will be added in when reproduction takes place. Therefore, people can find out when the common ancestor lived according to the length of the founder mutation gene. Other than that, the founder mutation migration provides proof for human migration. It provided evidence that human ancestor—Homo sapiens did not interbreed with other human groups. Accordingly, we can be sure that the modern human directly evolved from Homo sapiens. This also resolves the question asked in “Journey of Man” article: if the Native Americans evolved from early human groups other than Homo sapiens.