I'm sorry Bojac, I should have been more specific.
I'm not saying there is no merrit to the "x factor" I was more focusing on Stone City's diagrams and statements saying that Mayday recieved no influence from Miss Jocko and the like. If his staement had been, Mayday recieved no SEX linked characteristics, well that's a whole new ball game.
What you posted above states that the X and Y chromosome THEMSELVES are resistant to recombination, which makes sense, as certain traits are REQUIRED for each sex. It also makes sense then, that there ARE sex linked traits. Yet, everyone seems to be forgetting the 38 other chromosomes passed down from each parent.
I think the post above by stone city that speaks of the horses shows how the "x factor" "COULD" come in handy. IE, Horse researchers have shown that the large heart is directly linked to the X chromosome. I know of no such sex linked traits in our dogs, although I would love to see some examples, and with the discovery of such you could use the "x factor" as valuable breeding tool.