I want to take a DNA test but I am skeptical about its reliability. Any thoughts on this?
I’m not an expert in this but I have taken the DNA tests offered by Ancestry and 23andMe, so perhaps my experience will be helpful to you. First of all, you need to understand the limits of DNA testing. You should know that there is no such thing as a complete database of human DNA samples. More so, there is not even a sufficiently globally-representative one. When you take a test, the database of existing samples is searched for matches against your DNA. This means that the quality of the match will depend on the size of the comparative samples. Because every company has its own database this means you will get different results.
Second of all, if you are not a white European you will not get the most thorough match. Although the size of the reference population of a database is crucial, this is not all that matters. Variety is also important in DNA matches. For example, if you are a non-white customer with an ethnicity other than European, you will get less accurate results because they draw from a much smaller subset of DNA samples. In this scenario, I highly recommend doing some investigation into the various databases used by companies who offer DNA testing.