Theory of Evolution by Natural Selection

Vocabulary Evolution: It refers to the process by which populations change over time. Mutation: It is a change in genetic material.

What did Darwin observe? Darwin observed and collected many living and fossil specimens. He did important observations on the Galápagos Islands. He kept a log (journal) that was later published as The voyage of the Beagle.

Darwin observations on the Galápagos Islands. He observed that plants and animals were different from one island to another.

Natural Selection It is the process by which organisms that inherit advantageous traits tend to reproduce more succesfully than other organisms do. It has four parts: Overproduction Genetic Variation Selection Adaptation

Overproduction When a plant or animal reproduces, it usually makes more offspring than the environment can support.

Genetic Variation Genetic variations are natural differences that can be passed on form parent to offspring. An important variation is a mutation.

Selection The living things select the traits they will need to survive.

Adaptation An inherited trait that helps an organism to survive and reproduce in its environment.

What happens to species as the environment changes? Changes in environmental conditions can affect the survival of organisms with a particular trait. Environmental changes can also lead to diversity of organisms. Some species adapt, some species may become extinct.