Answer:
Positive natural selection.
Explanation:
The positive natural selection is a type of natural selection that increases the frequency of an allele or trait when it is advantageous for the population. What happened in the example is that the mouth with the slight change in morphology (trait) was more advantageous for the population in the south in relation to the ancestral morphology (still preserved in the population in the north), and therefore its frequency increased. This, in turn, is due to the fact that the food (prey) is not the same in the two habitats (north and south). The specific prey in the south, caused the new morphology to be selected, (increasing the frequency of individuals with the new mouth), becasue probably that trait allows the trouts in the south to hunt more effectively.
The littoral zone<span> is the part of a sea, lake or river that is close to the shore. In coastal environments the littoral zone extends from the </span>high water mark<span>, which is rarely inundated, to shoreline areas that are permanently submerged. It always includes this </span>intertidal zone<span> and is often used to mean the same as the intertidal zone. However, the meaning of "littoral zone" can extend well beyond the intertidal zone and that is you answer</span>
Hair follicles is the hair coming out of the subcutaneous layer
A. Heat will not flow because there is no temperature difference between the substances.
