This update will address the growing importance of SNP testing in genetic genealogy. We have now reached the point that SNPs are relative to genetic genealogy in addition to providing data on deep ancestry.
Many of the new SNP haplogroups have origins of 1000 years ago or less and as the geneticists discover new downstream haplogroups we have arrived in some cases at the genealogical time frame. Just like STRs, SNPs can mutate at any time. Anywhere from 20,000 years ago to only 100 years ago. The geneticists are now identifying the more recent SNP mutations. And this is where it gets interesting... not only are the more recent downstream SNPS being located, but mutations on those SNPs are also being discovered.
A mutation on the Haplogroup identifying SNP is called a ‘private SNP’ or some prefer the term ‘Family SNP' or a 'Unique SNP’ A Private SNP occurs at such a low level that it is not used to define a Haplogroup. But, it is the unique genetic signature of a particular family or kinship group. These Private SNP mutations are extremely useful for genealogists and family historians, especially among Irish and Scottish families that use patronymic surname traditions. Usually, these Private SNPs produce small cluster of surnames, two to four or so.
What this means to us we have a tool to identify clan and sept groups and the linked geographic area. From this data we can locate primary sources to unlock the history of that match group. Many of our members have already done extensive SNP testing and even the Big-Y test and know their Private SNP. Those results are very detailed and so large that they are not posted on the public results page. Participants of the higher level SNP test download the data and share with other private scholars and genetic genealogists.
Family Tree DNA has some education material on SNP testing on their website. I urge family groups to appoint one person in their kinship group to ‘read up’ on SNP testing. Having the data is one thing, but one must also know how to use it.