A derived character, also known as a derived trait or apomorphy, is a feature that has evolved in a particular lineage and is not present in its ancestors. These characters help in distinguishing different groups of organisms and are significant in the study of evolutionary biology.
For instance, the presence of feathers in birds is a derived character that distinguishes them from their reptilian ancestors, which lacked this feature. Derived characters provide important information about the evolutionary history and relationships among species. They are often used to build phylogenetic trees, which represent the evolutionary relationships based on shared derived traits among different groups.