One of the most amazing outcomes of evolution is Batesian Mimicry, where an edible species is protected from predation by resembling an inedible or dangerous species. For instance, the poisonous Monarch Butterfly (Danaus plexippus) is mimicked by the edible (and probably very tasty) Viceroy Butterfly (Limenitis archippus).
So, this type of mimicry can lead to the remarkable convergence of two species, but David Pfennig and his colleagues now document an intriguing case of possible divergence (and maybe even speciation) caused by Batesian Mimicry. And they provide some evidence for this suggestion based on … clay necklaces. Seriously!
Snakes in Disguise
The system of this study, published in the journal Evolution, encompasses the nonvenomous Scarlet Kingsnake (Lamproptelis elapsoides) and the venomous Eastern Coral Snake (Micrurus fulvius). These species live together in the southeastern United States.
Batesian Mimicry can lead to divergence between species if it contributes to reproductive isolation between members of different species. In other words, hybridization is prevented or hybrids are at a disadvantage. The latter hypothesis was tested by placing “hybrid clay necklaces” in the field and consequently checking if they were attacked by predators more than normal snakes.
In only one region, the Carolina Sandhills, were hybrid necklaces attacked more than the normal ones. There is thus some evidence for predation-mediated selection against hybrids. More research is definitely necessary to see if Batesian Mimicry can result in speciation. But what I find even more amusing , is thinking of three grown men making “snake necklaces” in the name of science…
Pfennig DW, Akcali CK, & Kikuchi DW (2015). Batesian mimicry promotes pre- and postmating isolation in a snake mimicry complex. Evolution, 69 (4), 1085-90 PMID: 25689670