Convergent Evolution in Small Mammal Antisnake Defenses
by Bree Putman
Fitness is determined by two things: survival and the propagation of one’s DNA. Individuals that survive longer than others have more chances to reproduce and thus pass on their genes. Their success will determine the genetic makeup of the next generation (the foundation of natural selection). Predators act as one of the strongest selective forces in nature because once eaten, an individual is neither able to survive nor reproduce. It’s no surprise then that animals evolve many unique ways to deter predation.
Rattlesnakes and some other venomous snakes hunt in a stereotyped manner called ambush hunting. They remain stationary at a hunting site, patiently waiting for unsuspecting prey to wander by. They employ a rapid strike, during which they embed their fangs into the prey’s body. They inject venom into the prey, then typically release it and let it succumb to the venom before ingesting it. Because most venomous ambush-hunting snakes around the world do not drastically deviate from this general strategy, their prey experience almost the same predation pressures. Thus, prey have independently figured out similar ways to avoid being eaten by ambush-hunting snakes.
This post is part of the Reptile and Amphibian Blogging Network’s #CrawliesConverge blogging carnival, running from 20th April to 5th May! It’s all about convergent evolution of reptiles and amphibians! Follow the #CrawliesConverge tag on Tumblr and Twitter to keep up to date with our posts!