Evolutionary biology is a subdiscipline of the biological sciences concerned with the origin of life and the diversification and adaptation of life forms over time. Ancient DNA reveals how the ...

and transitions between species mark the flow of evolution. But in fact, scientists and philosophers have debated for centuries the precise definition of a species. In high school biology we are ...

Evolutionary developmental biology is the comparative study of organismal development and how it has evolved. There is a particular focus on the genetic basis of phenotypic structures, how they ...