How To Find New Family Members

Many people whose main aim is to find new family and who are looking to use DNA testing as an investigative tool might have already done some research on their family tree, may well have gone as far as they can by conventional means and have hit a brick wall but want to explore their ancestry further. For people in this category their aim is to find cousins that they were previously unaware of, make contact with them, share information about their common ancestors and see if they can to join up there family trees through known relatives or through the new investigative leads they gain from each other. The nature of the inheritance of the three different kinds of DNA means that, in general, testing the kind of DNA known as autosomal DNA is best for finding previously unknown family members because it can detect all strands of your ancestry and not just unbroken male and female blood lines.

Autosomal SNP Tests
If this is your goal the best place to start is with an autosomal DNA SNP test (see also Testing More Distant Relationships). SNP tests were first introduced in 2007, are the most technologically advanced and analyze hundreds of thousands of points throughout each of your 22 autosomal chromosomes. The tests give a measure of how much of your DNA you have in common with another person and this measure is used to estimate how close or how distant your relationship is. If you are trying to find new relatives your results are compared with everyone on a database containing the results of all individuals previously tested by your chosen company. The testing company then put you in touch with those on the database who are likely to have a recent common ancestor with you.

There are three companies who provide this type of DNA service, all at $99 per test (plus shipping): 23andMe, Family Tree DNA and AncestryDNA ( All are based in the US but 23andMe and Family Tree DNA offer the same service to customers globally. Like all tests that try to connect related people, it works by comparing your results with those held on a database containing all the individuals that have been previously tested using powerful software to search for close matches. If there are significant similarities in your DNA with other people you will be given the chance to contact them by email to explore your common ancestry.

As explained in Family Tree and DNA Inheritance, because we have many more distant cousins than we do close cousins, it is more likely, for example, that 4th cousin matches will be found rather than 2nd cousin matches and the more distant the relationship the less likely it is you will be able to share relevant information and connect your family trees. The chances of being given links to cousins with whom you share a recent ancestor is obviously dependent on how many of your extended and distant family have also been tested by the same company.

At the moment the majority of customers on all databases built up by the three testing companies are from the US although there are significant numbers globally particularly from Britain and Europe. Even for US customers the numbers of people on the SNP databases at the moment are small when compared with the total US population (databases contain between fifty thousand to a couple of hundred thousand people depending on the company) and so the chances that you will be connected with very close relatives is not great. In other words it is more likely you’ll be connected with 4th and 3rd cousins rather than 2nd cousins – and bear in mind that it may be difficult to discover a non-DNA connection with a third cousin as you are only likely to share one out of eight pairs of your great, great grandparents. Even still, I think these tests do offer excellent value for money because a) you may be lucky and connect with a close relative, b) you may very well be interested in more distant strands of your ancestry, after all it is part of your heritage, c) more and more people are taking the test, databases are growing quickly and the service you receive is ongoing in that you will continue to receive new connections when you match with new customers being added to the database (as long as companies continue to offer the current testing platform), d) the tests include fascinating information about your ancient biogeographically origins, in other words what world populations does your unique mix of genetic material originate from?

Which Company?
It depends, here are a few things to consider – for autosomal SNPs, 23andMe have the biggest database but unlike Family Tree DNA they don’t offer Y-DNA or mtDNA testing and therefor don’t facilitate an holistic DNA approach using all the different DNA tools. 23andMe tests include a breakdown of your medical susceptibility to many DNA linked health conditions. This is a benefit if you are keen to know medical information but it also means that some of their customers are interested in the health aspects only and don’t respond to requests to connect with the genealogy links that are discovered by the test. Also for customers outside the US, 23andMe shipping charges are much higher than from Family Tree DNA. There are several other differences too that you can look through yourself by following this link Autosomal DNA Testing Comparison Chart to the International Society Of Genetic Genealogy (ISOGG) website.

Y-DNA and mtDNA Tests
For the purpose of connecting with your genetic  cousins, these tests are much less powerful than autosomal SNP DNA tests because they only capture a thin strand of your genetic heritage (unbroken paternal and maternal lines) and also because Y-DNA and mtDNA types remain unchanged for many generations – so if you have an identical match it may be that your common ancestor lived many generations back in time. Both types of test are sometimes used in standard relationship testing and many companies offer them, so, if your aim is simply to investigate a relationship between two people without any wider genealogical purpose then there is lots of choice. However, if you want mtDNA and Y-DNA information about your deep ancestral roots Family Tree DNA and specialize in this area (23andMe don’t offer Y and mtDNA tests). Both of these companies offer deep ancestral information on the ancient origins of your male and female lines.

If you are willing to invest the resources and are keen to investigate all aspects of your DNA heritage either purely out of enthusiastic curiosity or because you have lost ties with your family through adoption and are keen to leave no stone unturned, Family Tree DNA have large databases containing Y-STR and mtDNA test results from large numbers of people and these can be searched for matches and possible links to relatives not unlike autosomal SNP tests, albeit with a lower chance of finding close relatives.

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