Tree diagrams have been used in evolutionary biology ... If they remain apart for long periods, enough physiological and behavioral differences may evolve to result in reproductive isolation ...

We've long assumed our species evolved from a tidy ... In some situations, this makes quite a mess of the neat and tidy tree ...

As long as the same type of organisms appear ... evolutionary relationships), they are able to construct more and more accurate tree diagrams. But how do they figure out relationships between ...