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, ...

Sexual dimorphism in plants encompasses the morphological, physiological and phenological differences between male and female reproductive functions. In dioecious species, separate individuals bear ...

Sexual dimorphism, the systematic difference in form between males and females, is a pervasive feature of animal biology. One of its most studied manifestations is sexual size dimorphism (SSD), in ...

A new study by researchers at the University of Chicago and the City College of New York has identified a unique, genetic “mimicry switch” that determines whether or not male and female Elymnias ...

Charles Darwin was a careful scientist. In the middle of the 19th century, while he was collecting evidence for his theory that species evolve by natural selection, he noticed it didn’t explain the ...