Genetic Anthropology: New Understanding through Genetic Testing

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Genetic Anthropology:
New Understanding through Genetic Testing

Genetic Anthropology:
New Understanding through Genetic Testing
Genetic Anthropology is the study of combining DNA evidence with physical evidence to understand the history of modern human. These scientists and anthropologists are trying to understand where and when the branches of ancient and modern human existed (U.S. Department of Energy Genome Program, 2010). This field of research focuses on two main ideas. The first focus is to develop a data base of living human to compare genetic markers. These genetic markers will show how different cultures relate to each other. The second focus is to compare current genetic markers to the fossil found in the field to develop an evolutionary track of human migration and try to find out how modern humans evovled (Marks, 2012).

There are many models of how Homo saipan evolved. The Multiregional Continuity Model suggests that Homo erectus left Africa and moved into the Middle East, Europe, and Asia. Then these different groups evolved simultaneously into Homo saipan without direct connection to each other. The other main theory is the Out of Africa Model. This model suggests that Homo saipan evolved in Africa and then migrated into the Middle East, Europe and Asia. The leading theory in Genetic Anthropology is the Out of Africa Model (Johanson, 2001).

DNA studies indicate that all modern humans have a common female ancestor through the use of PCR. By looking at mitochondrial DNA, this common female ancestor, “genetic Eve,” lived in Africa about 140,000 years ago. The “genetic Adam” lived in Africa about 60,000 years ago by looking at mutations in the Y chromosome DNA. Other fossil evidence suggest that homo Saipan was not the only homo species living at the time and homo saipan still shares some common DNA markers from these other homo species. These ancestors of homo Saipan are now part of a growing fossil record of ancient human migration patterns indicating that modern humans arose from sub-Saharan Africa about 65,000 years ago. These modern humans moved to southern Asia, China, Java, and later Europe over the next 65,000 years (U.S. Department of Energy Genome Program, 2010).

Scientists use two forms of DNA to understand the different generations. The Y chromosome is passes only from father to son. The Y chromosome allows scientists to trace paternal lineages. Plus, mitochondrial DNA (mtDNA) is passed from mother to child and allows scientists to trace maternal lineages. Both Y chromosome DNA and mtDNA will go through harmless mutations that become genetic markers for certain populations. As different species of humans migrated scientists can look for these genetic mutations in different populations and the age of the fossil will show when these groups lived (U.S. Department of Energy Genome Program, 2010).

Mitochondrial DNA is found and made in the mitochondria of a cell. Mitochondria are structures within the cell that convert energy that the body takes in to energy that the cell can use. Every cell has thousands of mitochondria that surround the nucleus in the cytoplasm of a cell (Genetics Home Reference, 2012). Mitochondrial DNA can only be passed down from mother to children, thus only daughters will pass this genetic information to the next generation of children. This genetic information can be used to develop phylogenetic tree for modern humans evolved (Sorenson Molecular Geneaolgy Foundation, 2007).

Y chromosome DNA is present in males. Since there is only one copy of the Y chromosome from each male, there is no recombination with each new generation. Instead, the Y chromosome is passed down directly and nearly unchanged from a father to a son. Y chromosome DNA only gives information about the direct paternal line. However, since Y chromosome DNA only has subtle mutations, its genetic information can be...
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