In response to the rep - absolutely nothing posted here is actually essential to human survival. If the species just wants to live, all it needs is things to eat, something to drink, and a sharp stick.
I wonder if our progression would be very different without the condom, or other effective methods of contraception. What would life be like if sex were still laden with the very possible eventuality of children? Would we still be living in a very sexually reserved society where sex was only for married couples, or would we have moved into a stage where children are no longer seen as something you should only try and have with a life partner? Would kids with multiple partners now be the norm?