Question

When certain traits increase the likelihood of an animal living a long life, it is referred to as _________.

Answer 1

When certain traits increase the likelihood of an animal living a long life, it is referred to as natural selection.
 
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Photon

Answer 2

Natural selection is the answer. Natural selection is a process which organisms adapt more in their surroundings to survive longer. Therefore, when certain traits increase the likelihood of an animal living a long life, it is referred to as natural selection.