About Genetic Genealogy

Genetic Genealogy is the practice of using genetics testing to prove ancestral connections. The Human Genome Project allowed scientists to completely sequence all of the genes within the human body and develop many different types o genetic tests as a result. There are two specific types of genetics tests that are used for this purpose - Y-DNA and MtDNA, both of which discussed in more detail below. A third type, Autosomal tests, can be used to find recent family members on both sides of the family.

Regardless of which type of DNA test you are looking at, the results are grouped into one of 26 different Haplogroups, lettered A-Z. A Haplogroup is a range of specific values at specific markers and they generally coincide with specific geographic regions on the Earth, so Haplogroup Q will generally be found in different places than Haplogroup R.

Y-DNA

Y-DNA tests determine paternal ancestry. These tests specifically measure the values of Y-chromosome markers that are passed down from father to son. The number of Y-Chromosomes that are included in the test vary greatly from testing company to testing company, and most of them have different levels of tests. Some common test sizes are 12, 25, 37, and 111 markers. Y-DNA chromosomes are generally very stable and change only slightly from generation to generation. Due to this, they are excellent for determining parentage. This test can trace the paternal line back 200,000 years

MtDNA

MtDNA is short for Mitochondrial DNA and is used to trace back the material line of the family. There are specific markers that are passed down from mother to daughter and this test capitalizes on those results and provides a list of matches. These markers are generally very stable over time and slow to mutate which makes them ideal for establishing parentage. This test can trace the maternal line back 200,000 years.

Autosomal

This type of DNA test looks at all of the markers in your entire genome and can sort the results into paternal and maternal matches. This type of test is really only viable for about 5-6 generations.