Transcript Natural Selection and Evolution

Natural Selection
and Evolution
Objectives
• Students will be able to– Explain the theory of natural selection
– Apply the theory of natural selection to
hypothetical situations.
– Identify frog and amphibian similarities to other
species.
Did you see any animal variation at the
Zoo? Why do you think there was so
much of it?
Did you see any animal variation at the
Zoo? Why do you think there was so
much of it?
Animals are suited to their environment.
What do you know about the following terms?
• Natural Selection-
• Adaptation-
• Population-
Population
• Population- Individuals species that live
together in one place at one time and can
interbreed.
Natural Selection
• The process by which individuals that have
favorable variations, and are better adapted
to their environment, survive and reproduce
more successfully than less well adapted
individuals.
Adaptation
• An inherited trait that has
become common in
population because the
trait has provided a
selective advantage.
Question/Example
• In a natural frog population, the skin color
varies from red to blue to green. None of the
frogs are poisonous, but there are a lot of
predators in the area. The surrounding are is
covered with green plants. Who is most likely
to survive?
Question/Example
• In a natural frog population, the skin color
varies from red to blue to green. None of the
frogs are poisonous, but there are a lot of
predators in the area. The surrounding are is
covered with green plants. Who is most likely
to survive?
Question
• If natural selection is the reason behind
successful adaptations, why don’t beavers
have chainsaws?
Question
• If natural selection is the reason behind
successful adaptations, why don’t beavers
have chainsaws?
Genetic Variation
• There has to be variation that can be inherited
in order for Natural selection to take place.
• If a population happens to have the genetic
variation that allows some individuals to
survive a particular challenge better than
others, then those individuals will have more
offspring in the next generation