Y-DNA: STR and SnP tests.

FamilyTreeDNA offers five different STR tests. Relationship between STR matches is determined by genetic differences (GD) on the Y chromosome. When a GD becomes too great (around 10% or more of the number of markers tested), it is unlikely that the two people share a common ancestor within a genealogical timeframe (i.e. since about 1,200 C.E.). 

SnP (snip) tests look at mutations on the Y chromosome. These results reach beyond a genealogical timeframe, leapfrog over genealogical brick walls and will place a man on the tree of mankind often forming a new branch. Whereas STR tests predict the haplogroup (the ancestral clan) a man belongs to, SnP testing will confirm a haplogroup.

Big-Y:  FamilyTreeDNA’s main SnP test offering is the Big-Y.  While it is their ultimate, most informative and conclusive Y-DNA test, it is also the most expensive. However, after one male in a particular family takes this test, other males do not need to.

Where to start? Someone new to Y-DNA testing might want to start with a Y-37 or Y-67 test.  If you want more information, you can decide to upgrade later. If you want the most information about your Y line, you might want to jump in with the Big-Y test. Watch for sales that occur year-round, often at holidays.