Here's a link regarding the Cohanim [Kohanim]. Really interesting study. I found out a couple of years ago that I am a Cohen [we're not a very observant family [img]/images/graemlins/smile.gif[/img] ], and started looking up some info and came across the study of Cohanim genetics.
http://www.aish.com/societywork/scie...connection.asp
Of course, I've broken pretty much every rule of the Cohanim. Married a convert? check. Been to graveyards? Check.