If there were a brown bear and a white bear in the Antarctica, the brown bear wouldn’t survive as well as the white bear because it wouldn’t be able to camouflage and everyone would be able to see it. So then, that one would die off and wouldn’t pass its genes through, it wouldn’t have kids and it wouldn’t be able to pass them on. But the white bear could have kids and pass it on and then they would have the white gene and they would keep passing it on and they would survive better than the brown bear.
In the DNAs again like your personality, like some people have blond hair and brown hair and the parents might have it and the grandparents might have it and they would …. their parents might not have it and then they pass it on. The parents would have the gene but they might not be using it and the kids might use it.