The question that brought me back to this thread is really a wish to know what differentiates the genome of one species from another. Like they say there is only about 5% difference between the human genome and the chimp genome. That 5% of the human genome then must contain the coding for what is specifically human and not ape, and same with the ape genome.
Think about it like
a blueprint, or
a set of instructions for creating the organism.
Both the chimp and human DNA instruct the creation process to be making (not necessarily in order) bilateral symmetry, then an anus*, and then form a mouth, a spinal cord, head, two arms, two legs, fingers and toes, etc.
Those instructions for forming those things are the same DNA in both chimps and humans.
*as Deuterostomes, which means the anus forms before the mouth, all of us at one point in our lives, were just assholes
The problem with that argument is that it justifies my claim that it wasn't a mutation but a regularly occurring allele.
Not necessarily. It could be similiar mutations occuring at different times, or it could be a different mutation causing a similiar change in fur color.
There's more than one way to get a black mouse.
It would have to keep recurring after all for your scenario to be true and not just be eliminated completely by the predator.
No it gets completely eliminated and then later another different black mouse pops up again. And then it gets eliminated. Then another different one pops up, but wait... this time he ends up in a dark colored environment. So he thrives and passes the gene on. It could be a different mutation than the earlier ones that didn't make it.