In one type of animal, the gene for a long tail (T) is dominant over the gene for a short tail (t). Two animals with long tails are crossed, and 25% of their offspring have short tails. Which diagram correctly shows a Punnett square of this cross?

Asquirrel population lives in an area. over many years, a river in that area grows wider and stronger, eventually forming a canyon. the squirrel populations on the two sides of the canyon can no longer mate with each other and ultimately form distinct species. this is an example of