Evolution is unfolding in real time within many natural animal populations and researchers are now observing how this influences biodiversity in the field. In a newly published study in Molecular Ecology a team of Drexel University scientists examined the biological variations in pea aphids, insects that reproduce frequently enough to evolve before our eyes, by tracing the prevalence of their protective endosymbiont, Hamiltonella defensa, which the insects use to ward off parasitoid wasps.