What is referred to as the differences in appearance between males and females of the same species?

The concept described in the question pertains to sexual dimorphism, which is the distinct difference in physical characteristics between males and females of the same species. This may include variations in size, color, shape, and structure among other traits. Sexual dimorphism often arises due to differences in reproductive roles and pressures, leading to males and females developing distinct physical traits over time to enhance their mating success and survival within their environments.

For example, in many bird species, males may exhibit brighter plumage to attract females, while females tend to have more subdued colors for camouflage. This differentiation aids in reproduction by helping to attract mates and can also play a role in territorial behaviors.

In contrast, sexual selection refers to the evolutionary pressures that shape traits linked to mating success but does not solely define the actual physical differences themselves. Sexual reproduction is the process by which offspring are produced from the genetic material of two parents, which is unrelated to physical distinctions. Genetic polymorphism refers to the occurrence of two or more different forms, or alleles, within a population but does not specifically relate to the differences between sexes. Therefore, sexual dimorphism is the most accurate term to describe these observable differences in appearance between males and females of the same species.