How do people make claims about the % composition of their ancestry? The answer is a simple DNA ancestry test that can make inferences from hundreds to thousands into the past! Genetic genealogy or genetic ancestry testing is a process used to learn about biological relationships between individuals or to determine ancestry by the process of DNA testing (with historical and genealogical records). With various companies that provide such service, not many people understand the tests that take place, what data they can gain from this service and this article will tell you exactly that. DNA testing is a topic worth exploring in any projects for Biology.
Paternity testing (Y chromosome) is used to explore the male line since only males have this chromosome. This test uncovers males’ Y chromosome haplogroup which is a stretch of Y chromosome that you share with male relatives in your paternal line and this is done by looking at one single nucleotide polymorphism which is a variation of one DNA nucleotide at a single position in the DNA sequence. They can also be determined by looking at short tandem repeats where a short sequence repeats itself. These two can help determine the similarity in a haplogroup because they will have the same differences in their DNA.
Maternity testing (mitochondrial) is used to explore the female line but can be tested on both sexes. When you take the mtDNA test, the HVR1 and HVR2 (Hyper Variable Region) are analysed, which are a small set of base pairs at the end and beginning respectively. These regions mutate once in every fifty generations. This type of DNA analysis allows you to go back thousands of years.
After getting this data, it is compared against reference data set from different ancestral lines from different ethnicities and then created probabilities for where each part of DNA might have come from. This therefore created problems for people of colour since they are severely underrepresented in global genetic studies. The data set they have for these groups is too less compared to the whole population, which is why the online DNA tests might not be entirely accurate. Furthermore, it is also said that these single nucleotide differences are just representative of the general geographical area and this doesn’t mean the test can prove the person’s ethnicity, rather where the DNA overlaps with. Therefore it is said that ethnicity or race might be different from what genetic ancestry might say. The uncertainty in research and how the technique actually works, in depth, is an interesting topic for research and definitely needs more work.
Articles used:
“Dna.” Y, www.ancestry.com/lp/y-dna.
Jack Herrera | Published Dec 27, 2019 9:35 PM. “Dna Tests Can't Tell You Your Race.” Popular Science, 26 Apr. 2021, www.popsci.com/story/science/dna-tests-myth-ancestry-race/.
“What Is Genetic Ancestry Testing?: MedlinePlus Genetics.” MedlinePlus, U.S. National Library of Medicine, 21 Sept. 2020, medlineplus.gov/genetics/understanding/dtcgenetictesting/ancestrytesting/.
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Tim Barclay, PhD. “The Best DNA Test for Health IN 2021: Dna Health Testing.” Innerbody, Innerbody Research, 29 June 2021, www.innerbody.com/dna-testing/dna-health-testing.
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