In the history of life on earth, sex may be the ultimate survival skill, because the bottom line is: reproduce or die. This episode looks at sex in its many forms, from sharks--among the first vertebrates to have intercourse--to dinosaurs that had to figure out how to join their giant bodies together to mate; from the stick insect (that mates non-stop for 10 straight weeks) to macaques monkeys (about once an hour)... and finally to humans. This driving force of life comes in many forms. How will sex evolve in the future? Are we evolving beyond sex? In fact, is a time coming when we will be able to seize control of our own evolution... not via sex at all, but through genetic engineering?