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Darwin's theory of natural selection has four principles: variation, heritability, overproduction, and reproductive advantage. Explain each of these principles using the example of dark fur polar bears and white fur polar bears living in Antarctica.
Variation - populations have different traits/phenotypes.
Heritability - traits can be passed down to future generations.
Overproduction - more offspring are produced than can survive.
Reproductive advantage - the offspring that do survive have the favorable trait and they will continue to pass it down to their offspring.