Final answer:
Sex-limited inheritance is determined by sex-limited genes that are activated in one sex but not the other, leading to different physical characteristics known as sexual dimorphism, influenced by natural selection and reproductive strategies.
Step-by-step explanation:
Sex-limited inheritance can be explained by the actions of sex-limited genes. These are genes that are present in both males and females but are expressed in only one sex, leading to different traits or phenotypes in each sex. For instance, specific genes may cause male elephant seals to grow larger and engage in combative behaviors, while instructing female seals to remain smaller and avoid fights. This results in sexual dimorphism, where the two sexes display distinct physical characteristics.
In the context of evolutionary biology, natural selection can influence the expression and prevalence of these sex-limited genes based on reproductive success. For example, studies have shown that sperm-depleted males may exhibit a behavioral preference for mating with larger, more fecund females when their sperm count is low, increasing the efficiency in the use of their limited reproductive resource.