[Bigh4u2]

"But some time after the mutation, and the recessive gene is propagated through the population, it becomes more likely to double up and become the expressed gene in an individual, rather than the old dominant gene."

That makes better sense!

Sorta like a cancer, that may be dormant in your system for years, that suddenly appears.

Thanx.

[doc30]

Maybe the cancer analogy is more apt than you think. Perhaps cancer is one form, albeit a lethal one, of expression of such 'new' genes. Two paths are present - one that leads to new adaptation, the other to illness and frailty. Then, obviously, the adaptable form will persist. The cancer forms are just dead ends. So the mutation occurs at one point in time, then at some future point, it becomes manifestly dominant under the pertinent situation.