Genetic Genealogy: The DNA Test to Understand Your Origins
You know the so-called "classical" genealogy, but do you know genetic genealogy? This discipline, which appeared about a decade ago, links genealogy and genetics through the use of DNA tests.
To conduct genetic genealogy, it is essential to carry out DNA tests which are relatively simple to perform and purchase on the internet: just buy a DNA test kit from AncestryDNA, Family Tree DNA, My Heritage DNA, iGenea, LivingDNA, 23andMe, etc...
To collect the DNA, a little saliva is enough to carry out the research. These tests measure the level of genetic relationships between several individuals. DNA sequences are compared to estimate the probability that individuals share one or more common ancestors. There are several types of tests:
- The Y-DNA test that tests only the paternal line
- The mitochondrial DNA test that tests the maternal line
- The autosomal DNA test that tests the DNA inherited from both lineages.
1. Y-DNA: The Paternal Test of the Y Chromosome
This DNA test focuses only on the genealogy of the father and his male ascendants. It is therefore part of what is called, in genealogy, agnostic research. The Y-DNA test allows you to discover which haplogroup (genetic group from common ancestors) you belong to while giving you a percentage of your genetic origins. Represented on a map of the world, the result allows to know the migratory route of the haplogroup to which you belong, and thus, that of your ancestors. Does your paternal lineage come from Europe, Asia, Africa, America? This test lets you discover it!
2. Mt-DNA: The Maternal Test with Mitochondrial DNA
It is called "mitochondrial DNA" or "Mt-DNA" because it is a test performed on mitochondria, concentrated on a certain region of the DNA. This test allows you to establish the female lineage of your family. Like the Y-DNA test, it allows you to understand your geographical origins back to about 50,000 BC which is the Paleolithic era.
3. ADNa: The Autosomal DNA Test
Since the autosome is a non-gender-specific chromosome, the autosomal DNA test can be performed on both men and women, giving it a significant advantage. In addition, it compares almost entire genomes to determine their degree of kinship and percentages of genetic mixing between populations, without necessarily having a large number of samples from the populations studied. Thus, the autosomal DNA test remains today the least expensive test and the most commercialized.
Be careful however: it is a chromosome inherited from both parents, and it is impossible to know the proportion of provenance. For example, two sisters can record different results since they received a random genetic inheritance. The conclusions drawn from the results are therefore approximate and give you the percentages of your origin, such as X% African, Z% European etc.