What is Y-DNA?
Y-DNA is a type of DNA that only males have, and it is passed down with very few mutations from fathers to sons. Because surnames are also inherited from fathers, Y-DNA is a great way to track families by their surnames. When Y-DNA has a certain type of minor mutation (a “SNP,” or single nucleotide polymorphism), and a father passes down that new (mutated) Y-DNA to his son(s), it creates a new grouping of people with a certain pattern of Y-DNA. This group is called a “haplogroup.”