Coevolution of venom function and venom resistance in a rattlesnake predator and its squirrel prey.
Measuring local adaptation can provide insights into how coevolution occurs between predators and prey. Specifically, theory predicts that local adaptation in functionally matched traits of predators and prey will not be detected when coevolution is governed by escalating arms races, whereas it will be present when coevolution occurs through an alternate mechanism of phenotype matching. Here, we analyse local adaptation in venom activity and prey resistance across 12 populations of Northern Pacific rattlesnakes and California ground squirrels, an interaction that has often been described as an arms race. Assays of venom function and squirrel resistance show substantial geographical variation (influenced by site elevation) in both venom metalloproteinase activity and resistance factor effectiveness. We demonstrate local adaptation in the effectiveness of rattlesnake venom to overcoming present squirrel resistance, suggesting that phenotype matching plays a role in the coevolution of these molecular traits. Further, the predator was the locally adapted antagonist in this interaction, arguing that rattlesnakes are evolutionarily ahead of their squirrel prey. Phenotype matching needs to be considered as an important mechanism influencing coevolution between venomous animals and resistant prey.
Department of Evolution, Ecology and Organismal Biology, Ohio State University, 318 W. 12th Avenue, Columbus, OH 43210, USA holding.5@osu.edu.
Matthew L
0000-0003-3477-3012
ML
Holding
Biology Department, Fairfield University, 1073 North Benson Road, Fairfield, CT 06824, USA.
James E
JE
Biardi
Department of Evolution, Ecology and Organismal Biology, Ohio State University, 318 W. 12th Avenue, Columbus, OH 43210, USA Ohio Biodiversity Conservation Partnership, Ohio State University, 318 W. 12th Avenue, Columbus, OH 43210, USA.
H Lisle
HL
Gibbs
D000222:Adaptation, Physiological; D000818:Animals; D005075:Biological Evolution; D003435:Crotalid Venoms / Q000633:toxicity; D017839:Crotalus / Q000502:physiology*; D004777:Environment; D005843:Geography; D008954:Models, Biological; D010641:Phenotype; D011235:Predatory Behavior; D012589:Sciuridae / Q000502:physiology*
D003435:Crotalid Venoms
coevolution; local adaptation; molecular variation; predator–prey interactions; resistance; venom