Aa Aa Aa Most people have a basic idea of what species are, even if they are not sure of the best way to define the word species. Quite simply, species are kinds, or types, of organisms.

But in fact, scientists and philosophers have debated for centuries the precise definition of a species. In high school biology we are told that species are communities of individuals that can ...

A species is a distinct group of organisms and the most basic unit used to measure life on Earth. However, there’s no single definition of a species, meaning this vital concept in biology can be ...

All viewers of this document can see this public note. This is the most explicit and concise description and definition of natural selection in On the Origin of Species. Darwin’s view here is ...