Aim 27: Theories of Evolution

Evolution- is the change in a species over time

A. is based on the organisms phenotype

B. A change in the gene pool over time

C. A shift towards a particular trait that is beneficial

Jean Baptiste Lamarck

tried to explain how organism is change

inheritance of acquired characteristics

Organisms passing down traits that they acquire to their offspring

use and disuse

if an organism uses a body part it will become bigger and the body part not being used will get smaller

Organism strive toward perfection

Each generation evolves toward perfection

Charles Darwin and Alfred Wallace

A. Both came up with the idea of evolution

B. Both stated that organisms that look similar share common ancestor

natural selection

Those best adapted to their environment will survive reproduce

overproduction

too many offspring are born that can possibly reach reproductive maturity

Competition

Between members of the same species for resources, such as food, shelter, water, and mates

variations

our differences within individuals of a species that help them survive

adaptions

are beneficial changes to an organism that are passed down to the next generation