Thanks for the replies, I appreciate that you've taken the time. It's a pitty that I didn't found what I was looking for.
-Lemur: If you read the FULL question and the comment I made to alpha2cen, you will see that is extremly clear that the second thing that you answer is what I was asking. But, your answer is completly unsatisfactory since you're guessing; wich is not even close to what I'm looking for (would it be ok for you an answer like that? I don't think so, you probably want accurate cientific data). In any case, I take it as an "I don't know". Thanks anyway.
-Charon Y: "Dominance in genetics is a relationship between two variant forms (allels) of a single gene, in which one allele masks the expression of the other in influencing some trait" (wikipedia). I tottaly understand wich expression means, understand this: the phenotype only manifests if the gene is expressed first and gets transported by the messenger RNA so that the protein can get maid (I'm not some woman that wants to know if their kids could be blond if that's what you were thinking). If you check in all of my posts, the term is used perfectly.... plus, you didn't gave any answer to my question. If you can, I would be very grateful, since I really want to know.
LET'S REPHRASE THE QUESTION:
--What is the physical particularity of this genes (the dominant ones) over the others, and what is the evolutionary purpose?
Don't tell me what dominance does or is, tell me what produces the dominance not its effects.
If I ask you what causes rain, you should say something like "the collition of clouds", and not "the fact that water is falling from the sky".
