DNA Genealogy

Someone requested that I write about Molecular Family History.  Be warned, I am a medical lab science major and a Family History nut.  You have released the kraken. 

So, with molecular biology becoming more and more advanced, this kind of application is becoming cheap enough, reliable enough and fast enough to be viable.  It used to be that sequencing someone's genome, even just the Y chromosome and the mtDNA (which are the most widely applied for family history purposes), was much too expensive and people would rather do Family History the old fashioned way.  But today, all 23 chromosome pairs can be used easily, plus the mtDNA. 

mtDNA is Mitochondrial DNA.  The bizarre thing about mtDNA is that every single piece of it comes solely from ones mother.  You do not have any paternal DNA in the mtDNA.  So, this makes it the perfect thing to trace matrilineage. They have been able to trace most people to a couple of mtDNA lines, which can quite accurately tell you where your mother's mtDNA originated and where it migrated.

Similar to mtDNA, but for the paternal line is Y chromosome genetics.  The down side is that only boys can do this (but if you have a brother, use his).  The Y chromosome is the chromosome that conveys "maleness."  Because of this, every boy got his Y chromosome from his father.  There are only a few Y chromosomes out there.  Different things have mutated onto them, but there are a few basic lineages and these can tell you where your father's ancestors went and wandered.

The last thing that is nice about genetics in family history is that you can find relatives to collaborate with.  They may be your 3rd cousin, but they have a lot of family history in common with you to collaborate. 

Genetic Family History companies can tell you your genetic ethnicity to focus your research and open up possibilities for family history.