Evolutionary biology is a subfield of biology that studies how species start and change over time; or in other words, how species evolve. Someone who studies evolutionary biology is known as an evolutionary biologist.
Evolutionary biology became an academic subject as a result of the modern evolutionary synthesis in the 1930s and 1940s. It was not until the 1970s and 1980s that universities had departments which used the term evolutionary biology in their titles.
As a result of the rapid growth of molecular and cell biology, many universities have split their biology departments into molecular and cell biology-style departments and ecology and evolutionary biology-style departments. These have absorbed older departments such as paleontology, zoology, botany and the like.