Monogamy a Myth?

Last night, after helping my Mom hang some curtains I put Baby Girl to bed and sat down to blog, of course, and watch a bit of TV. I turned to 20/20 where Stossel was doing a special, "Sex in America". It was one of those, yeah, yeah, heard it before things, but there was a guy on there being totally blatant about being a "bad boy", or as I like to refer to him, pig. Sooooo, he claims that evolution decrees that men and women cheat. Men cheat more, and he says rightfully so...spread the seed, yada, yada, yada. I've only been married 3.5 years, and neither my husband nor I are close to spousal perfection, BUT, if we went into the marriage with the thought that monogamy was a myth?...what's the point? Some may feel that way, but I think I'll go ahead and continue giving monogamy a shot, ya know?