Sexual Dimorphism
Anthony Perez
Anthropology
May 8, 2013
Sexual dimorphism is the difference in morphology between male and female members of the same species. Sexual dimorphism includes differences in size, coloration, or body structure between the sexes. Dimorphism means two forms. “Sexual dimorphism” is two sexes of a species differ in external appearance or other features. Males and females may differ in size, color, shape, the development of appendages (such as horns, teeth, feathers, or fins), and also in scent or sound production. Species in which male and females are identical in appearance or other features are said to be “monomorphic.” There are different types of dimorphic traits found in marine mammals and explains some of the reasons why these traits might have evolved and what can be inferred about the lives of males and females in a particular species from the pattern of sexual dimorphism. The quality of the information available on sexual dimorphism varies widely across marine mammal species. We know quite a lot about a few species, which are used repeatedly as examples, and virtually nothing about others. Despite some of the difficulties of observing marine mammals, understanding of the evolution of sexual dimorphism is increasing steadily as studying of rarely encountered species accumulates and new techniques are further developed.
Sexual dimorphism has fascinated biologists since before the time of Darwin. Darwin considered that most sexual dimorphism was due to sexual selection, in which evolutionary forces acted separately on the sexes (Darwin, 1871). For example, females might choose to mate with highly ornamented males or males might develop characteristics or traits useful for fighting with other males to win in contests for access to females. Today, these two processes are often referred to as female choice and contest competition. More recently, scientists have learned that males compete not only by physical fighting and display but also, in species
Anthropology
May 8, 2013
Sexual dimorphism is the difference in morphology between male and female members of the same species. Sexual dimorphism includes differences in size, coloration, or body structure between the sexes. Dimorphism means two forms. “Sexual dimorphism” is two sexes of a species differ in external appearance or other features. Males and females may differ in size, color, shape, the development of appendages (such as horns, teeth, feathers, or fins), and also in scent or sound production. Species in which male and females are identical in appearance or other features are said to be “monomorphic.” There are different types of dimorphic traits found in marine mammals and explains some of the reasons why these traits might have evolved and what can be inferred about the lives of males and females in a particular species from the pattern of sexual dimorphism. The quality of the information available on sexual dimorphism varies widely across marine mammal species. We know quite a lot about a few species, which are used repeatedly as examples, and virtually nothing about others. Despite some of the difficulties of observing marine mammals, understanding of the evolution of sexual dimorphism is increasing steadily as studying of rarely encountered species accumulates and new techniques are further developed.
Sexual dimorphism has fascinated biologists since before the time of Darwin. Darwin considered that most sexual dimorphism was due to sexual selection, in which evolutionary forces acted separately on the sexes (Darwin, 1871). For example, females might choose to mate with highly ornamented males or males might develop characteristics or traits useful for fighting with other males to win in contests for access to females. Today, these two processes are often referred to as female choice and contest competition. More recently, scientists have learned that males compete not only by physical fighting and display but also, in species