Viruses and their hosts influence each other’s evolution. As selection acts on viruses to increase their ability to infect hosts, selection is acting on hosts to decrease their susceptibility to viruses, and the next generation of viruses is less effective at infecting hosts. But the viruses continue to evolve, as do the hosts–they coevolve and often demonstrate this pattern:
This is called the Red Queen Effect, after the Red Queen from Through the Looking Glass by Lewis Carroll.
Human settlement has typically meant one thing for large carnivores: certain doom. Both people and predators rely on large tracts of land for habitat and other animals for food, and intensely compete for these resources. Europe is an example of a human-dominated landscape almost devoid of large predators. A diverse community of animals that are used for food (prey), such as roe deer and wild boar, have healthy populations regulated by hunting rather than predation by historically native carnivores such as brown bears (Salhen et al. 2016). Prey species use a variety of methods to detect predator presence, but a very common way animals do this is by scent (Apfelbach et al. 2005). If a deer detects a predator’s scent, they will change their behavior to escape. These abilities may fade over time if predators disappear from the landscape, as the ability to detect predators would no longer be part of the animal’s early learning. Due to conservation efforts, large carnivores are going through a sort of revival in Europe (Sahlen et al. 2016). Predators are recolonizing areas that they have been absent from for centuries. The increase in predators in Europe is a conservation success, but how will this affect prey populations? Without experience escaping from these predators, will they be obliterated? Continue reading “Detecting smelly enemies: how a “fixed-ability’ can maintain predator avoidance”