Variations There can be many different variations For a trait. Variations of a trait can increase or decrease an organisms chance of survival in an environment

Variations Stabilizing Selection is natural selection that favors average individuals in a population.

Variations Consider a population of spiders in which an average size is survival advantage. Predators might see and capture spiders that are larger than average, and smaller spiders might find it hard to find food

Variations Directional Selection occurs when natural selection favors one of the extreme variations of a trait.

Variations For example a population of For example a population of woodpeckers pecking holes in woodpeckers pecking holes in trees to eat insects living trees to eat insects living under the bark. under the bark. Suppose the insects live Suppose the insects live deep in the wood of the tree. Only woodpeckers with long beaks could feed on that insect. deep in the wood of the tree. Only woodpeckers with long beaks could feed on that insect.

Variations Disruptive selection occurs when either extreme of a trait is selected.

Variations Consider a population of marine organisms called “Limpets.” The sell color of limpets ranges from white to tan to dark brown. On light-colored rocks white shelled limpets have an advantage On Dark colored rocks, dark-colored limpets have an advantage

Variations Species that were once similar to an ancestral species becomes increasingly different Adaptive Radiation- Change to fit diverse habitats…. Wat UP Cousins!!!

Variations Two “Distant”-ly related organisms develop the same traits… Flying Squirrel Flying Phalanger Do I know You? Are we related?