Sexual Dimorphism in Arctic Foxes

1473 Words6 Pages
Sexual Dimorphism In Arctic Foxes Abstract Sexual dimorphism is an observable difference between males and females of the same species. Using Arctic fox (Vulpes lagopus) , we tested the hypotheses that canine size and bite force are sexually dimorphic . These traits were chosen to understand the evolution of adaptations and whether they influence reproductive success and survival of the organism. The results showed both canine size and bite force to be sexually dimorphic. Males had a larger canine size and bite force compared to females signifying their ability to feed efficiently , which is important for growth and survival and possibly mating success. Introduction The observable difference between males and females of the same species is called sexual dimorphism. Sexual dimorphism in size and morphology are is visible throughout the animal kingdom. Charles Darwin’s sexual selection hypothesis states that sexual dimorphism evolves when characters that have an advantage in either competition for mates or mate choice are selected for within one sex (Hendrick et al.,1989). However, it was noted that in some cases, sexual dimorphism could have evolved from food competition between sexes, or differences in the reproductive roles. For instance, the energy needs for reproduction in female lizards may be much higher than males’, resulting in females consuming more prey than males (Givens,1978) . Sexual dimorphism at so many different levels of function and development provides us with an insight into the meaning of sex within nature. Animal growth is influenced by quality and availability of food. Analysis of the feeding patterns and feeding structures of animals will give an insight on food availability, nutrition intake and evolutionary changes in the organism. The study of feeding structures is significant in tracing evolutionary history and is a
Open Document