I can’t count the times I’ve been asked questions about dna for genealogy kits. There are lots of places that offer them, and the price has come way down. The problem is, so has the quality and usefulness.
In 2000, Family Tree DNA, founded by Bennett Greenspan and Max Blankfeld, was the first company dedicated to direct-to-consumer testing for genealogy research. They originally tested in partnership with the University of Arizona, and were quick to address privacy issues. FTDNA is still ahead of the pack in that regard. I was fortunate to meet and Bennett Greenspan not long after, and got a personal introduction to the concept of DNA for genealogy. He also made sure I understood what these tests CANNOT do.
The first company to provide direct-to-consumer genetic DNA testing was GeneTree. It did not offer multi-generational genealogy tests, and was defunct for quite awhile. In fall 2001, GeneTree sold its assets to Sorenson Molecular Genealogy Foundation (SMGF) . SMGF provided free Y-Chromosome and mitochondrial DNA tests to thousands. GeneTree came back to genetic testing for genealogy in conjunction Sorenson and eventually was part of the assets acquired in the Ancestry.com buyout of SMGF.
By August 2019 about 30 million people had had their DNA tested for genealogical purposes. What these test results are will likely upset and frustrate some of those folks. None of the tests will tell you who your missing ancestor is. None of them. They simply provide general data analysis. Your test is only compared to the others from the same company. That comparison uses an algorithm to see what your dna “numbers” most closely match and where those matching people are, and in a very general way. If there is a match with up to for differences, and if you have given permission, the companies will exchange contact opportunities between the matches. You may find a cousin or two, but unless the people in your family are tested, finding a complete match is unlikely.
You then take this information and go back to traditional research methods. New surnames may be collateral lines from a female. If you are fortunate enough that your match has created a family tree with a database, you can share your research. Remember to get documentation!
There are many things that DNA for genealogy won’t do. It won’t prove native heritage for government acknowledgement. It won’t tell you where your ancestor immigrated from. I’ve even heard of people getting these test to “prove” they are “all white”. Not only is this disgusting, it also doesn’t work. There are few people alive who have pure race dna. The most likely place to find those few would be untouched tribes in Africa, but realistically we’re all a mix.
For more information about the basics of DNA and how this all got started, I recommend reading The Seven Daughters of Eve by Sykes. I also recommend that if you do take one of these tests, you read and keep a copy of all of the legal disclaimers. Pay special attention to who they share their data with and exactly what is getting shared.