Narrator: This is Science Today. In simple terms, biological evolution is a change in a population's inherited traits from generation to generation. Albert Bennett, a professor of ecology and evolutionary biology at the University of California , Irvine says it's important to understand evolution because it's essentially about the ability of biological systems to cope with change.

Bennett: For whatever reason, we live in a very changing world. The world has always been changing and populations of organisms are always trying to keep up with climate change or with the invasion of another kind of animal or plant into their environment. They're always trying to cope with those sorts of things. Or within a new disease organism arises, trying to cope with that – all of these are evolution.

Narrator: Bennett's expertise is the evolutionary and comparative physiology of animals. For Science Today, I'm Larissa Branin.