Model of human migration based on Mitochondrial DNA
Recently my wife was reading Kathy Reichs novel where she has described about mitochondrial DNA (mtDNA). Kathy Reichs is also producer & writer of the popular TV series Bones. Before hearing about mtDNA, I had very little idea about any types of DNAs, except Y & X chromosomes. My DNA knowledge is/was limited to doing paternity test ews. :)Scientists believe that all origin of human life on earth can be traced back to East Africa. Human mitochondrial DNA haplogroup are used to represent the mtDNA tree. Using this, evolution of life can be traced back to Africa approximately 170,000 years ago. Surprisingly mtDNA is transferred (or inherited) from one’s mother.
mtDNA & Y-chromosome are used to trace ancestry. mtDNA is generally passed unaltered from mothers to children of both sexes, along the maternal line. Whereas DNA in the Y-chromosome, called yDNA, from father is passed only to son. Y-chromosome is highly susceptible to mutation due to environment they are housed in or the process of passing it thru sperm. This means that a male may never pass his Y-Chromosomes if he only has female offsprings. But what’s the point of passing the gene if its not the same?
Reading more on this I realized how misinformed our society is. Unlike common belief, it is the female lineage that is carried forward, not the male. Our society behaves quite opposite to that, where bloodline & lineage is primarily associated with men. In reality men are just the source of providing the sperm for the egg. mtDNA of a man are transferred thru sperms & are destroyed by the egg after fertilization, so in a way male mtDNA is not carried forward. yDNA is highly mutable so may not be same as that of grand fathers.
