Characteristics controlled by a single gene (one copy inherited from each parent) tend to have phenotypes that fall into separate categories. They show discrete variation.

Complex quantitative traits, like size and behaviour, are a pervasive feature of natural populations. Quantitative trait variation is the product of both genetic and environmental factors, yet little ...

Biologists discuss findings from an investigation of genetic mutations in seven species of North American stick insects (Timema) resulting in cryptic coloration. Traits that form an organism's ...