Final answer:
Sex differences in body size and other characteristics among the same species, known as sexual dimorphism, arise due to evolutionary pressures that favor characteristics leading to increased reproductive success.
Step-by-step explanation:
The term you're inquiring about that refers to differences in physical or physiological characteristics between males and females of the same species, such as body size, is known as sexual dimorphism. These differences can extend beyond the reproductive organs, resulting in varied traits like height, muscularity and even behavioral aspects. In studying the impact of sexual dimorphism on species, it's evident that these traits can influence the reproductive success of the individuals, with some species displaying role reversal where females are selected for larger body sizes or more elaborate traits that are typically characteristic of males.
This refers to the evolutionary process in which characteristics that lead to increased reproductive success tend to be favored and thus become more prevalent in the population. Sexual dimorphism can arise from significant selection pressures, such as males competing for mates or females selecting mates based on certain attributes like size or coloration. In many animal populations, there is more variance in the reproductive success of males than that of females, which drives the evolution of pronounced differences between the sexes. For example peacocks have elaborate tails developed through sexual selection by peahens who preferentially choose mates with more impressive displays. The understanding of sexual dimorphism is central to studies of biological sciences and provides insight into the evolutionary pressures that shape the biodiversity and behavior of various species.