A population of pigs lives on an island together with burrowing termites. Pigs that have the longest snouts tend to survive more frequently than those with shorter snouts. Over time, most of the pig population is made up of individuals that have very long snouts. This is an example of which type of selection

Directional selection

Explanation:

Natural selection is the process which determines the trait of the organism with which a species can evolve. This process can take place in one of the following ways that are stabilizing selection mode, disruptive selection mode and the directional selection.

When nature selects the species with the extreme trait and only one extreme trait is favoured over other than the population shift towards that particular trait and shows the directional selection.

In the given question, the pigs with longer snouts are favoured more than the pigs with another length of snouts therefore nature selects the pigs with an extreme trait and the population shifts towards that trait. This selection is known as the directional selection.

Thus, directional selection is correct.

stress fractures occur largely in the feet and legs and are common in sports that require repetitive impact, primarily running/jumping sports such as gymnastics or track and field.

answer: ice crystals in air

the water from the water body or another source of water gets evaporated as water vapor as an effect of heat on water. these water vapor rises in the upper layers of the earth atmosphere under high atmospheric pressure. the atmospheric pressure of these water molecules starts to decrease due to the effect of cold air. the invisible water vapor condenses into visible water droplets and ice crystals.these ice crystals and water droplets being less denser than the surrounding air floats on air as clouds.