Friday, December 28, 2007

Genealogy and DNA

Advances in DNA testing has opened up a new arena in genealogical research. We now have the ability to track our ancestry based on the X and Y chromosomes that we inherit from our parents. By comparing the DNA test results with others, we can determine to what extent we are related to others around the world.

Discover Ancient Ancestry

In addition to finding genetic cousins, DNA test can also reveal our ancient origins. Beginning over 170,000 years ago, our ancient human ancestors migrated out of Africa and began their slow and steady spread across the continents. Over time as these ancestors spread throughout the world and adapted to their new surroundings and environments, their DNA diversified and they became genetically distinct from one another. Today, these differences can be traced through DNA and provide insights on how our ancient ancestors migrated and diversified into distinct populations.

DNA and Genealogy

All humans have 23 pairs of chromosomes, including a pair of sex chromosomes, known as "X" and "Y". Males have both an X- and a Y-chromosome (with the Y-chromosome inherited from the father) while females have two X-chromosomes (one X-chromosome inherited from each parent.) Genetic Genealogy is interested in heritage markers or the area of the chromosome which reveals family relatedness.


Because the Y-chromosome is passed essentially unchanged from father-to-son, it provides genetic genealogists with a powerful tool for tracing a paternal lineage. Specific portions of the Y-chromosome are analyzed and compared against other participants' Y results to determine the relatedness between the two participants.


Since both parents contribute X-chromosomes to their daughters, a different source of DNA must be used to trace the maternal line. Mitochondrial DNA (mtDNA) is inherited by both male and female children exclusively from their mothers and provides insight into one's maternal lineage.

This is just a brief overview of genealogical research with DNA. I will be expanding this analysis and providing more insight into the industry, the tests, and, ultimately, which company we should partner with to expand our research.

Next, I will review the industry and what each of the major companies have to offer.


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