In my research into my Cruwys ancestors in Devon, I hit a brick wall trying to find William George Cruwys (born 1821), the brother of my great great grandfather, Thomas Cruwys (born 1831). William disappeared from English records after the 1841 census. I found a William of the right age in Prince Edward Island, Canada, but couldn’t find any records to confirm a link, though naming patterns provided a strong clue.
DNA is found in most cells of the body, including white blood cells, semen, hair roots and body tissue. Traces of DNA can also be detected in body fluids, such as saliva and perspiration because they also contain epithelial cells. Forensic scientists and Police officers collect samples of DNA from crime scenes. DNA can also be collected directly from a person using a mouth swab (which collects inner cheek cells). Find out more in the article Crime scene evidence.
AncestryDNA recently updated their service, adding new regions and adjusting their algorithm to make their ethnicity estimates more accurate. You're not alone in being a bit bewildered, since plenty of people have had their results change unexpectedly. As genetic ancestry analysis is a relatively recent science and is improving all the time, your results will become more accurate as more people enter the Ancestry database, allowing them to hone their algorithm accordingly.
Even though we are all unique, most of our DNA is actually identical to other people’s DNA. However, specific regions vary highly between people. These regions are called polymorphic. Differences in these variable regions between people are known as polymorphisms. Each of us inherits a unique combination of polymorphisms from our parents. DNA polymorphisms can be analysed to give a DNA profile.

Hi Mark, Thank you for such an informative and clearly stated article. I am American Jewish and have done several of the tests. I’m now submitting a question for a close friend. He is Burmese and would very much like to test. His biggest interest is ancestral origins. Would he be best off doing a Ydna test or could he find sufficient information in an autosomal test? I assume the Y test would be with Familytree. If so, should he also do an autosomal test with Familytree, or with Ancestry or MyHeritage? Thank you so much!
Some concerns about the ultimate efficacy of certain home tests seem to emanate from the industry itself. I did a telomere-measuring test (a mouth swab) by Titanovo, based in north Colorado, which came back saying that my telomeres were too short, putting me at 10 biological years older than I am. However, when I contacted Titanovo, it explained that it had stopped telomere measuring and was now concentrating exclusively on its DNA-utilising “bioinformatics” health, fitness and wellbeing website (analysing client data from other genetic testing sites).
1. Family Tree DNA’s Family Finder: One of the first to offer these types of tests, FTDNA is generally considered the leader in autosomal DNA testing for ancestry and provides some of the best tools available for genealogists. Their population finder section is currently a bit less specific than the other companies, but FTDNA Family Finder users are eagerly awaiting a much improved update to be released sometime in the next month. Find out about Family Finder here.
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