DNA testing, a genealogical tool
Called "recreational" by its opponents, mistakenly confused with medical tests, genetic genealogy tests open up new perspectives for the genealogist. Practiced for 18 years in the United States and around the world, genetic genealogy tests allow to discover its ethnic origins and to find genetic cousins. This additional tool discovered by genealogists confirms the declarative family tree, completes it or can partially disprove it.
Genetic data protected by the RGPD
By entrusting your saliva to one of the four major foreign laboratories performing these genetic genealogy tests, you are protected by the General Data Protection Regulations (GDPR). Thanks to the legalization of these tests in France, we would have the assurance that our authorities would be able to comply with the RGPD and the contract terms with the laboratory. However, particularly in the United States, these companies are vigilant about these privacy issues. Indeed, their U.S. users, the majority, in a private health care system, would risk a lot in the event of a sale of genetic data or leakage to insurance or mutual insurance. And those companies would risk bankruptcy lawsuits for breach of contract.
The contract with the companies entrusts them with our DNA so that these companies can make a comparison with other users' data. This service is now offered free of charge, in beta testing by Geneanet, one of the two major genealogy operators in France with Filae.
Ethnic data that can be surprising
With the panels in their possession, these laboratories will present your ethnic origins, with a different degree of precision depending on the laboratory: 42 geographical areas deciphered by MyHeritage against 1,000 different areas for AncestryDNA. Many of the tested may be surprised by these time-changing results. With each improvement in the ethnic panel, the origins may differ. As a user, we have lifetime access to refined results.
The lack of knowledge of this aspect of ethnic origins may have led to a judgment of unreliability of those results by the neophytes. It is no more or less a variable quality of service, as with any commercial service: some are more efficient than others or improve over time in the face of competition. The user must be informed in the face of sometimes misleading advertisements.
Genetic family tree
Genealogist for more than 30 years, I was able to appreciate the unique interest of these tests to complete our genealogy but also their limits. Let's go back to the genetic heritage of our ancestors present in our DNA. We have 23 pairs of chromosomes, the exact half of which is transmitted by the father and the other half by the mother. Each chromosome is a subtle assemblage of DNA segments inherited from each of our grandparents and great-grandparents. Each of us is a unique assemblage of the DNA of our ancestors up to the 6th generation before us, ancestors born between 180 and 240 years before us. This inheritance can extend to a few ancestors up to the 8th generation, especially in endogamic populations.
In a process of genetic genealogy, we will have every interest in having our older parents tested first, with more DNA than us, and therefore more ancient ancestors and genetic cousins.
By comparing it with the other DNA in the base, we will be able to find genetic cousins of unknown branches of our tree because they have emigrated to another country. By moving to another country, our ancestors used to change their surnames to better integrate into their new homeland. But the DNA remains unchanged.
The genetic genealogy test turns out to be the only tool to identify an unknown natural father, never declared, in our genealogy or biological family of an anonymously abandoned child and finally complete these cut branches.
Other genetic tests exist, such as the mitochondrial or Y chromosome test, opening up other exciting prospects for the genealogist. Historical riddles have been solved such as those of the children of US President Thomas Jefferson, who was romantically involved with Sally Hemmings, a slave.
A new tool that is little known, overvalued or despised, genetic genealogy tests should be put back in its proper place: a complementary tool for the genealogist, but a valuable tool, unique and sometimes indispensable.