There is only one problem with these donkeys theory. White skin genes aren't dominant.
>> There is only one problem with these donkeys theory. White skin genes aren't dominant <<
Actually, most spot mutations are recessive. The problem is that skin color is not recessive or dominant
Well, one problem with your problem is that recessive genes don't vanish, and in some cases no doubt thrive.
Assuming that a recessive gene appeared in one person, then the offspring of that person would have the recessive gene even if they did not express it. Some number of their offspring would also have the recessive gene, and sooner or later you will get individuals that express the recessive trait. If natural selection (including sexual selection) then favors those individuals then the gene will eventually predominate in the population.
I was thinking the exact same thing. Unless that single white skin individual REALLY "got around the block".