The Cowan YDNA results at the FTDNA site, as of February 2010, show that persons using the Cowan surname (or a variant) are characterized as belonging to a number of distinct Haplogroup. Most Haplogroups dveloped anywhere from a few thousand years ago to many tens of thousands of years ago, and are unrelated to the later adoption of a given surname. Thus use of a surname among persons bearing different haplogroup signatures indicates independent adoption of a surname. No genealogically meaningful connection would be expected between two persons using the Cowan surname, but belonging to different haplogroups. Nonetheless, those interested in the "deep" origin of their male ancestral line, may find the YDNA haplogroup data of considerable interest, because it tells us something about where, and when, a particular line originated. Thus Cowans bearing the "I" haplogroup may expect that their distant ancestor passed through Scandinavia as recently as 4K years BP, while others bearing the "G" haplogroup have male line ancestors who probably passed through the near east around 10K years BP.
The following table summarizes the haplogroups that have been identified thus far in the Cowan YDNA project. Data on the characteristics of different Haplogroups was taken from Wikipedia:Haplogroups and related articles at that site.
*As of Feburary, 2010. May include "lumping" of closely related halpogroups.
Note that by far, the most common Cowan YDNA haplogroup is "R1b1b2". This is commonly referred to as the "Atlantic Modal Haplotype", and formed from 5K to 8K years before present in western europe.