Adaptations SBI 3UO
Adaptation • According to Charles Darwin's theory of evolution by natural selection, the organisms adapt to their environment to become better fitted to survive and passing their genes on to the next generation.
Adaptation and Speciation • Evolution involves 2 interrelated phenomena: • Adaptation • species modify their phenotypes in ways that permit them to succeed in their environment. • Speciation • the number of species multiplies; that is, a single species can give rise to two or more descendant species. • In fact, Darwin maintained that all species are related; that is, any two species on earth today have shared a common ancestor at some point in their history.
aposematic signals • superficial characteristics, called used to warn potential predators of the animal's physical or chemical defenses.
Aposematicsignaling - mimicry An important aspect of aposematic signaling is the evolution of another defense, mimicry. A mimic is a predator or prey that bears a superficial resemblance to another species. The mimic resembles the model, which exhibits aposematic coloration. There are two forms of mimicry: Batesian mimicry and Mullerian mimicry.
Mimicry • Pebble plants try not to be eaten by resembling stones, praying mantises hope to lure prey close by resembling flowers. • For example one type of firefly mimics the light flashes and pheromones of another in order to catch it. • http://www.bbc.co.uk/nature/adaptations/Mimicry
Batesian mimicry • a palatable species mimics an unpalatable model, thereby gaining protection through the traits of another species. • to be effective, there must be a larger population of models than mimics so that predators are not clued in to the fact that they are being tricked.
Mullerian mimicry • involves two or more unpalatable, aposematically colored species that resemble each other in appearance. • This strategy evolved so that predators will learn more quickly to avoid animals with particular warning signs.