" You may not know it, but you're part virus.

At least, some of your genes come from viruses that slipped their DNA into the genes of our primate ancestors millions of years ago."

http://news.yahoo.com/s/livescience/20071114/sc_livescience/whatsinyourgenesancientparasites;_ylt=Ar8CUVph0e1.cCyY.TA0tREiANEA

Maybe that "junk DNA" isn't so junky after all?