Our DNA is our genetic blueprint. It can reveal much about ourselves and where we came from. Since we inherit DNA from our parents, who inherited it from their parents, the results from a DNA test lead us back to more than 50 generations. It essentially takes us back in our ancestral history.
What does a DNA test tell about you?
A DNA test can provide you information about your ethnicity. In most cases, an ancestry DNA test offers an estimate. Moreover, it tells details about your ancestor’s place in history.
So how does DNA testing work?
There are many ancestry DNA testing companies that provide you information about your ancestry. However, all of these use the same method. Using a saliva sample or a cheek scraping sample, scientists and biologists work out the individual genes in your DNA.
It takes about two months or eight weeks for an ancestral DNA testing company to provide results.
According to an article by Vox, 99.9% of DNA in all humans is the same. Hence, scientists analyze the genome that makes us different. This process saves a lot of time and effort.
We can’t explain how DNA tests work without delving into a bit of science.
Four nucleotides make up our DNA: Thymine, Adenine, Guanine, and Cytosine. For ease, the abbreviations T, A, G, and C are used. DNA consists of two strands that are bound together like a ladder. Each strand is made up of four nucleotides. Various combinations of these nucleotides make up individual genes.
When a DNA testing company receives a saliva sample, the first step they take is to extract the DNA. The company also makes copies of your DNA and breaks it up into short pieces. The scientists then sort out the genes. These pieces are also called SNPs (Single Nucleotide Polymorphisms), which we inherit from our ancestors.
The information regarding the SNP is fed into a database and compared with SNPs of other individuals. If your SNPs match with the SNPs of another individual, it means that you share that trait and, likely, share the same ancestry as well.
An engineer also runs a computer program on the DNA to provide estimates regarding your ethnicity. These algorithms are not 100% accurate.
Limitation of the ancestry DNA test
Most DNA ancestry companies use a database to compare ancestries. Each company may not have the same database, which can cause discrepancies in the results. Moreover, with each passing year, as more people take a DNA ancestry test, the database is likely to change, and so are the results.
However, it doesn’t mean that the results are inaccurate. Instead, the DNA results provide estimates regarding your ethnicities (in case you belong to a multiethnic group). Most ancestry DNA tests are about 90% accurate.
Another reason that the results might be slightly skewed is because of the availability of data. For example, there is more DNA data of people belonging to European countries. The same is not true for a minority group. For people belonging to European countries, DNA tests can lead back information about the ancestry to the exact country.
Should you take an ancestry DNA test?
Despite the limitations of a DNA test, it can reveal much about our ancestors. As the database used in DNA testing grows, so is the accuracy of the results. Another point to remember is that DNA tests also provide information about how much ancestral DNA you have inherited.
If you are interested in genealogy, such a test can help you to get to know about your history and heritage—even if it provides you with an estimate at best.