In a oak hickory forest in Pennsylvania, gray squirrel populations have been declining due to increased predation by hawks and other predators. At the same time, researchers have discovered that the average thickness of acorns in the forest have decreased by 15% due to lower feeding pressure from squirrels. What type of natural selection would this be an example of?
directional T/F

Directional -------- TRUE ✔

Explanation:

Directional selection is a kind of natural selection that as the phenotype (the observable characteristics) of the species moving towards an extreme instead of the mean phenotype or the other extreme phenotype.

This type of selection is observed in environments that experienced variation over time as in weather, climate, or food availability. It gives a population bell curve for a certain trait that moves either in the left or right direction as seen in the attached image.

It is important to note that animal predators can also lead to directional selection as the slower animals in a prey population tends to be killed and eaten as the directional selection will continually skew the population in the direction of the faster animals.

i think a) betsy can donate only blood to mark is correct because, mark and betsy have the same blood type. whereas nobody else has b+ blood so betsy can't donate to them.

mammal

explanation: