Genetics

“Genetics explains why you look like your father, and if you don’t, why you should.”– Anonymous

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You might have heard about genetic projects, such as mapping the human genome or tracing the origins of Kennewick Man, Cheddar Man, Ice Man or Ice Maiden. In addition to these famous projects, genealogists are beginning to use genetic testing to solve some of the mysteries not answered by paper records. One type of analysis uses the y chromosome (yDNA), which passes only through the male line. Another type of analysis uses mitochondrial DNA (mtDNA), which passes only through the female line. Geneticists can’t yet resolve other lines (for example, a mother’s father’s line or father’s mother’s line), but those lines can often be traced using genetic tests on a relative for whom the line is strictly paternal or strictly maternal.

Paternal DNA (yDNA)

All modern humans descend in the male line from a particular man, nicknamed “Genetic Adam,” who lived about 60,000 years ago. All living men have inherited his y chromosome (yDNA), along with the mutations that have accumulated in our individual family lines.

Maternal DNA (mtDNA)

All modern humans descend in the female line from a particular woman, nicknamed “Mitochondrial Eve,” who lived about 100 to 250 thousand years ago, probably in East Africa. Each of us has inherited her mitochondrial DNA (mtDNA), along with the mutations that have accumulated in our individual family lines.

Media Reports

More Information

  • Ancient DNA. Information about ancient DNA.
  • Bradshaw Foundation. Nicely packaged information about human origins.
  • DNA Portal. Chris Pomeroy explains how DNA testing can be used to supplement genealogical research, with information about other families who are doing or have done yDNA tests.
  • Family Tree DNA. Genetic testing for both maternal and paternal lines.
  • Famous DNA. Information about famous DNA tests.
  • Genealogical DNA Test at Wikipedia.org. A nice introduction to genetic genealogy.
  • Honoring Our Ancestors. Megan Smolenyak has written extensively on genetic genealogy. This website showcases her work.

Recommended Books

DNA Databases

Update September 14, 2021

The original of this page was drafted before 2000. Reviewing it in September 2021 I see many ways it is out of date. One thing that strikes me on a casual read is how much of the introductory info is now available elsewhere on the Internet, and in a much more accessible format. When I first drafted this page there was very little info available, and what it was presented in ways that were impenetrable to the beginner.

I’ve been gathering links to re-work this page but frankly, a real update is in the distant future. With that in mind I’ve decided to link some resources now, gather more from my notes, then re-work this page in small increments, as time permits.

In addition to these links, I also have a playlist at Youtube:

Revised Oct. 20, 2019 to repair broken links; Oct. 29, 2019 to add links; June 7, 2020 to remove link to a dead site; July 8, 2020 to repair broken links; Sept. 14, 2021 to add section.