Survival of the Fittest

Adaptations

traits that help an organism survive and reproduce

Adaptations are always linked to the ____

environment (adaptations help an organism survive in its environment)

Species

a group of organisms that can interbreed and have fertile offspring

Why are varieties/breeds not considered species?

Two different species *can’t* interbreed and have fertile offspring. Two varieties/breeds (from the same species) *can* interbreed and have fertile offspring

Selective breeding

breeders (normally humans) breed individuals of a species to get a desired trait (ex: breeding wolves to get a desired dog breed)

Natural Selection

The environment that a population is in selects for certain traits in individuals. Those traits become more common in the population & the harmful traits become less common

Artificial Selection

An outside force (ex: humans) deliberately selects a desired trait & makes that trait more common in the population

Mutations provide the ___ ____ necessary for natural selection to happen

raw materials

Evolutionary Arms Race

one thing improves, causing something different to improve (and the cycle goes on)

Biological Example of Evolutionary Arms Race

leaf insect improves its camouflage → its predators improve their ability to find the leaf insect → leaf insect improves its camouflage

What evolves? (populations or individuals)

populations

Evolutionary fitness

“reproductive success” - how likely an organism is to survive and reproduce

Intrasexual Selection

members of one gender choose to mate with members of the other gender based on how attractive a phenotype is (ex: peacock feathers)

Intersexual Selection

members of the same gender fight over the other gender - usually the bigger individual wins