Birds possess unique skin appendages called feathers that are derived from the outermost layer of skin cells. Feathers are important for several functions, such as flight, temperature regulation, ...

Difference in body size (or sexual dimorphism) between males and females is common across the animal kingdom. One of the most extreme examples of sexual dimorphism is found in the cichlid fish species ...

Some Caribbean lizards' strong sexual dimorphism allows them to colonize much larger niches and habitats than they might otherwise occupy, allowing males and females to avoid competing with each other ...

Sexual selection, including mate choice and intrasexual competition, is responsible for the evolution of some of the most elaborated and sexually dimorphic traits in animals. Although there is sexual ...

Modern pinnipeds (the group that includes seals, sea lions and walruses) show a range of sexual dimorphism (large differences in size between males and females) and mating systems that span the ...

The study of sexual dimorphism in human crania has important applications in the fields of human evolution and human osteology. Current, the identification of sex from cranial morphology relies on ...

Sue, the largest, most complete Tyrannosaurus rex in the world, lives at the Field Museum in Chicago. The specimen was named by Peter Larson, who founded the Black Hills Institute of Geological ...

Humans are sexually dimorphic, which means that males and females are, on average, different sizes. In humans, like most sexually dimorphic species, males are typically larger than females. Why does ...

Body mass plays an important role in shaping an individual's behavior, especially with respect to dietary behavior. Larger animals tend to consume higher quantities of low quality foods. In contrast, ...

Males are bigger than females, right? Generally, this is true of humans – imagine the extremes of Dwayne “The Rock” Johnson and singer Kylie Minogue. It is also true of other familiar mammals ...