Final answer:
Evolution favors hermaphroditism when the fitness of the hermaphrodite is greater than that of either males or females alone. Hermaphroditism can increase mating opportunities and ensure genetic contribution, but may also lead to inbreeding.
Step-by-step explanation:
Evolution favors hermaphroditism when the fitness of the hermaphrodite is greater than the fitness of the male or female.
In biological contexts, there is often significant variance in reproductive success between males and females of a species. Hermaphroditism can present an advantage in such scenarios because it allows an organism to self-fertilize, thus ensuring reproductive success even in the absence of a mate. One advantage of hermaphroditism is that an organism can mate with any other individual, which doubles the chance of finding a mate. However, a disadvantage is that it might lead to inbreeding, which can decrease genetic diversity and increase the risk of genetic defects.
Sexual dimorphism, the differential in form between males and females of the same species, is often a consequence of sexual selection pressures. For example, male peacocks have elaborate tails to attract females, while females may be less ornate. When there is variability in traits that affect reproductive success, hermaphroditism may be favored evolutionarily as it allows an individual to possess both sets of reproductive organs, thereby increasing their mating opportunities and ensuring genetic contribution to the next generation.