Exploring Your Ancestry Using DNA Testing
November 05, 2013
There is a growing trend towards using DNA testing to help trace one’s ancestry. But what types of information can be discovered using one of the many products on the market that are DTC (Direct to Consumer)? Are they worth the expense, and can they fill in information relevant to your family tree? There are currently several hundred genetic tests of many different types in use, with more being developed all the time. These tests offer direct examination of the DNA molecule, and there are also biochemical tests that will show enzymes, proteins, or chromosomes.
One interesting reason for DNA testing is to discover which “haplogroup” your DNA comes from. Ancestral origins dating back thousands of years can be revealed because there will be shared common ancestors possessing similar mutations.
Haplogroups most commonly studied are Y-chromosome (Y-DNA) and mitochondrial DNA (mtDNA), both of which are useful in defining genetic populations. The human genome has been found to contain about 25,000 genes, and normal people carry two copies of each gene, inherited from each parent. The “patrilineal” line will show Y-DNA and is passed from father to son, while mtDNA is passed down the matrilineal line, from mother to offspring of both sexes. Since neither recombines, Y-DNA and mtDNA change only by chance mutation with each generation. Clear as mud?
But mutational distributions based on modern sampling may not accurately represent ancient populations because, over time, populations migrate. So, mapping these distributions may not reflect where a particular population arose in the first place. For example: The “Irish” yDNA marker called R-M222 is very heavy in modern Ireland, but may not be where it originated. The samples have also been found in Britain and probably developed somewhere else before being more firmly ensconced in Ireland. However, DNA testing will show the approximate percentage of a particular group you have in your DNA.
Direct to Consumer tests do not require going through a health care professional. There are many types of DTC tests with benefits including ease of accessibility, privacy, and the promotion of proactive self-care. Possible risks include the lack of governmental regulation, possible misinterpretation of results, and other ethical concerns.
If you are interested in paying for a product on the market, this handy chart featuring the main DNA testing companies can be your guide, depending on what types of information you are seeking. Please click this link: http://www.isogg.org/wiki/Autosomal_DNA_testing_comparison_chart
Midwest Genealogy Center
Tags: genealogy, DNA