Entomology. insect. Sexual Selection Essay Example | Topics and Well Written Essays - 500 words

Entomology. insect. Sexual Selection - Essay Example The two point mandibles found in the male beetle are because of sexual selection. In the case of stag beetles, the males fight and the females choose the strongest. This ensures that the female choose and reproduce with males who posses their favourable characters. Sexual selection is only for male and that is why the male develop adaptive and non-adaptive features to attract the female. The male beetle genital morphology comprises of two outstanding and general models of morphological variation. This morphological variation includes swift evolutionary divergence both in shape and in complexity as well as poor relationship with body size as suggested by Simmons, Tomkins and Hunt (1999). The aspect of sexual selection causes these variations. Some of the variations are non-adaptive, for instance, the reduction of the scaling relationship between the genital size and the body size. The idea that evolution of new traits is followed by trade-offs is important in evolutionary studies. The weapons used by the male stag beetle in fighting can be physiologically expensive and are mostly trade offs with investment in other characters, like spermatogenic investment and wings. This investment into other weapons results in the evolution of mating strategies for the male beetles. For instance, the enlarged mandibles used for male-to-male competition. The male-male fight in sexua l selection accounts for the evolution of exaggerated traits used as weapons in male competition. The exaggerated characters can be responsible for the dispersal and ejaculatory strategies. The change of investment into other traits or weapons for competition can lead to evolutionary changes in life history characters. Since investment in exaggerated traits can cause trade-offs alongside other traits related to fitness, life history tactics are affected by evolution of sexually selected behaviour. During evolution, the males’ population