DNA Ancestry
DNA Ancestry is extraordinarily fascinating. To explain why, I will give a brief biology primer.
A human being has 23 pairs of chromosomes (so 46 in total). 1 of these pairs is known as the sex chromosomes, X and Y. A woman has XX and a man has XY. The cells in your body are called autosomal and have all 46 chromosomes. The only difference is in your sex cells, the sperm or egg. These cells are called haplontic and only have half of the chromosomes so 23. So a sperm will either have an X inside or a Y. An egg can only have an X.
When a sperm and egg come together you either get an X sperm with the egg or a Y. The Y will give a boy, the X a girl.
The interesting part about Y-DNA is that it is directly passed from the father to the son almost unchanged (though mutations almost always occur in small amounts). Starting with the most recent common ancestor who lived almost 100,000 years ago, it is possible to track the progression of the Y Chromosome through its mutations throughout the globe. This has been passed from fathers to sons for thousands of years. Through the annals of time unique mutations have occurred that show where our Y-DNA mutated and branched off. Through analysis of bones and other remains, scientists can track where your ancestors lived, and how you came to be where you are now!
The Y-DNA is a testament of your ancestry. Women (and men too) can also trace their ancestry through what is called Mitochondrial or mtDNA.
Inside each of your cells are organelles called Mitochondria. They are the energy producing units of the cell. They actually have their own special DNA too. The sperm and the egg each have mitochondria. The sperm’s mitochondria are located in the tail area to help them swim, as such they do not enter the egg during fertilization. The mother’s egg’s mitochondria provide the energy blueprint for the new human. As such one can trace their maternal ancestry literally back to the dawn of humanity to a woman known as Mitchondrial Eve. This woman was literally one of the first homo sapiens to walk the earth.
Tracking this it is possible to see where your maternal ancestors originated from literally the dawn of human history. It is an incredibly powerful genetic tool.
Getting this ancestry couldn’t be easier. All it involves is a simple cheek swab. Some of your cheek cells are taken and lysed (broken open). The sample is treated with various agents and put through a process called PCR which generates large amounts of DNA copies and these are used to see what your Y-DNA or mtDNA “haplotype” is.
The 22 marker Y-DNA test is $79 through Ancestry.com. I am going to do it! Then I’ll save the money for the mtDNA test. Interestingly enough, when I was doing an honors course at the U of M I actually did the mtDNA myself, but not the detailed marker test.