EVOLUTION IN REVERSE

Mar. 8, 2013 — In evolutionary biology, there is a deeply rooted supposition that you can't go home again: Once an organism has evolved specialized traits, it can't return to the lifestyle of its ancestors.

There's even a name for this pervasive idea. Dollo's law states that evolution is unidirectional and irreversible. But this "law" is not universally accepted and is the topic of heated debate among biologists.

Now a research team led by two University of Michigan biologists has used a large-scale genetic study of the lowly house dust mite to uncover an example of reversible evolution that appears to violate Dollo's law. Earlier examples cited include hip-hope music and people who are fans of reality television programmes.