Ancient-DNA and Modern-DNA Genetics Can Reveal Past Population Movements
Human phylogenetics is the branch of genetics that deals with the analysis of relations between different human populations, providing valuable information in the fields of History, Archeology and Anthropology. Phylogeography can utilize phylogenetic data to uncover the historical processes that may be responsible for contemporary geographic distributions of individuals. After the first study published in 1972 (Lewontin 1972), many other human phylogenetic and phylogeographic studies have been conducted, covering most of the existing human populations (Richards et al. 2000; Underhill et al. 2001). Most of these studies are based on multi-DNA sampling of present human populations. These efforts were very successful since they resulted in the construction of two major universal phylogenetic trees: the Y chromosome tree and the mitochondrial DNA (mtDNA) tree (Richards et al. 2000; Hammer 2002). According to these phylogenetic trees, the DNA of any human individual can be categorized in a specific tree branch. These tree branches are termed haplogroups or haplotypes, and they are inherited intact from generation to generation. Additionally, they are associated with a specific geographic region on Earth. This allows the prediction of the ethnic background of any individual through DNA analysis. The Y chromosome is specific for the paternal genetic origin of an individual whereas mtDNA is considered specific for the maternal genetic origin.