Non-human life differs from that because the environments are covered with like sewers, buildings, and roads. Green spaces such as parks, backyards, and undeveloped lots are scattered in among the developed areas instead of all connected together. Plants and animals have to deal with exposure to toxins from vehicles and loss of habitat and food sources.
So we’ll just use “R” and “r” for this example. If the mother AND father are heterozygous, then both of their genotypes are “Rr” if you work out the lumber square or use the foil method, the box would look like this: RR on top left, Rr on top right, Rr on bottom left, and rr on bottom right. So the genetic probabilities, using four as the sum would be 1:2:1
Polygenic dominates because it would be masked