Since late 2007, several “direct-to-consumer” or “DTC” genetic testing products have entered the marketplace, many of which offered some degree of autosomal ancestry analysis (including 23andMe, deCODEme, and Pathway Genomics, among others).
In early 2010, genetic ancestry testing company Family Tree DNA announced that it would begin offering a new genetic genealogy product (see “Announcing Family Finder – An Autosomal Test From Family Tree DNA”). The new product, called “Family Finder,” is one of only a very few autosomal genetic genealogy tests available to consumers.
The Family Finder test uses an Affymetrix microarray chip that includes over 500,000 pairs of locations called single nucleotide polymorphisms (SNPs) in your autosomal DNA. Once the SNPs are analyzed, FTDNA detects linked blocks of DNA that indicate a common ancestor. The number and size of these linked blocks is used to determine how recently or closely two people are related. From the Family Finder FAQ page: