Principle #1 Genetic variation There a thin coat brown polar bears and thick coat white polar bears. The trait that is most favorable is the thick coat white polar bears.
Principle #2 Overproduction & the struggle for existence overproduction: As the white and brown polar bears are born The brown ones are dying from not keeping warm from how thin their fur is. Struggles: The trait that is most struggling is the thin coat brown polar bears because they are struggling to keep warm and blend into the environment.
Principle #3 Differential Survival & Reproduction The thick coat white polar bears have a higher fitness and can keep warm and survive and is able to reproduce to make more of the gene.
Principle #4 Changes in Gene Pool The thick coat white polar bears become more common