Hi!
The selection in this case would be natural selection.
Natural selection is a process that involves organisms with favorable characteristics having a higher chance of reproductive success, and passing on their traits onto the offspring. This process, as opposed to artificial selection, does not involve human intervention and is a natural phenomenon.
In our case, whales with maximum length (the favorable trait) are mating on accord of their own, without external factors governing the process; hence, the selection is natural.
Hope it helps!
The arteries take deoxygenated blood back to the heart.
Due to natural selection in finding a mate, t<span>he </span>color<span> of the </span>dewlap would start to lighten slightly in order also to <span>adapt to their surroundings.</span>
<span>They often move much greater distances than the intact protein.</span>