Download Theory of Evolution by Natural Selection

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:
1.Overproduction
2.Genetic Variation
3.Selection
4.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.