Jews and Genes

What connection is there between Jews and genetics?  Better yet, is there an actual link between the two?  Does being Jewish mean you come with certain genes, and if you are not Jewish you lack in those genes?  All of these are really great questions, but will there ever be a solid answer?  In my opinion, probably not.  It is such a controversial issue as it is, so reaching some conclusion about it seems quite far fetched.

What makes a Jew different than others?  Personally, I think it's not the physical, genetical details but the emotional and belief systems the person holds.  It is very clear that Jews and Christians, share quite different beliefs and do things in different manners.  But that does not necessarily mean that Jews share the same genetic background.  Everyone has different traits to distinguish themselves to be unique, and there is no exception based off of religion or what not.

Consider this some food for thought - what makes a Jew stand out?  Do genes really matter or not?