The resemblance can also be due to very different causes. Wasps can transfer their genes to butterflies without causing any damage. At least, as far as is known.
A team of French and Spanish researchers has found wasp genes in butterflies, a finding that demonstrates the existence of natural transgenics.
The genes detected in the butterflies came from a type of wasp belonging to the Braconidae family, whose reproductive cycle includes parasitizing butterfly larvae and moth larvae.
In that process, they inject viruses that block the larval defenses. But "at some point parasitization failed and host larvae acquired one of those genes and incorporated them and domesticated them over the last hundred years", concludes the work of the Universitat de València and the Recherche Sur Institute. Biology of l'Insecte (IRBI-CNRS).