Final answer:
When species compete for the same resources within the same environment, natural selection can result in character displacement, allowing them to coexist by reducing competition through specialization. These changes can lead to evolutionary responses or even local extinction if one species cannot adapt.
Step-by-step explanation:
If species are competing for the same resource and live in the same area, natural selection may lead to character displacement or evolutionary divergence. This pattern of resource partitioning and specialization helps to minimize competition and allows multiple species to coexist. Such changes can be physical or behavioral adaptations that reduce the niche overlap and competition.
For example, consider the case where interspecific competition between cheetahs and lions for prey leads to evolutionary responses. If the prey is limited, lions may catch more prey than cheetahs. This pressure could potentially lead to the cheetahs either adapting to capture different prey, moving to a different area, or experiencing a decrease in population if they cannot adapt quickly enough.
Moreover, when one species gains an evolutionary advantage, the other competing species must also evolve to gain an advantage or risk being outcompeted. In some cases, the competition can be so severe that one species may become locally extinct if it cannot adapt or relocate. This principle is known as competitive exclusion.