This is a strange idea I had about the rib as being a chromosome. It was also based on the idea that women have only X-chromosomes, whereas the male is formed from one of the X-chromosomes becoming an Y-chromosome. If one created an Adam (male & female), would it not be easier to fashion it with all its chromosomes being X, and then, in order to introduce an asymmetry, change one to a Y - in essence seperating the male and the female forms?

Here is a diagram of this idea, with a couple of ideas added in.