Sexual selection can explain sexual dimorphism. Male elephant seals are huge (weight 1500-3700 kg) but with a billowy belly so the female (weight 350-600 kg) is not pressed to death at times of amore ashore. The biggest and most belligerent bulls are hundreds of times more successful in siring offspring because they can keep a harem of cows. The cows are the exclusive nurtures of the seal pups, and some adopt if they lose their own.
In general, this is the key tendency for selecting the most suitable male for making progeny, as male should possess the best genes for survival. If a pair is growing their offspring together, the male should be able to protect it, as predators regard them as a simple prey. (Infanticide Figure 11.16, chapter 11) Hence, the males are larger, more powerful and more healthy. If a competition is not observed, the dimorphism is featured by brighter coloring, larger tail / mane / comb etc, as the larger and the more attractive males are regarded to be more healthy. Hence, the reproductive success depends on the variation of getting mates. As it is stated by Freeman and Herron (345), a heritage variation generally signifies the existence of trait that influences the entire ability to obtain mates. Hence, the larger mating success means that the offsprings will get the more traits for successful mating.
Asymmetric limits of on reproductive success generally cause the traditional patterns of natural selection, as mating is the lot of the healthiest, largest, most active, most powerful or most skillful. These limits are explained by the necessity to regulate the balance between the most suitable and less suitable for mating males. However, males with better parameters are preferred more, and in accordance with the observations, control males lose weight quicker due to more frequent mating instances (Figure 11.18)
Asymmetric limits, and the way they influence reproductive success are closely linked with the traits of the males, as independently on the mating period, females will choose the most suitable.