1. Remember! • Charles Darwin is known for his work on evolution by natural selection. • Natural selection is supported by many studies. What is natural selection?

2. What do you think is about to happen?

3. A quick simulation of evolution… • Peppered moths in the industrial evolution • http://www.utdanacenter.org/texteams/downloads/scienceresources/pradeep_fla.swf

4. Natural Selection How does natural selection cause evolution?

5. Natural Selection • The process by which organisms who are better adapted to their environment will survive & reproduce • “Survival of the Fittest” • Fitness: ability to survive & reproduce • High fitness means best adapted, NOT NECESSARILY THE STRONGEST! Some bears have the ability to dive into the water to catch salmon, but some bears don’t. Which bears have the higher fitness?

6. How does natural selection drive evolution?

7. Variation Within a Species • Different organisms within a species have differences in morphology & physiology! • Morphology: the form or shape of an organism • Physiology: the mechanical, physical, & biochemical functions of living organisms Morphology Physiology

8. Physiology – some of us have a fast metabolism, while some of us have a slow metabolism! Morphology – some of us are tall, while some of us are short!

9. These differences change the ability of an organism to survive and reproduce (fitness)!

10. Adaptation • Any inherited characteristic that increases an organism’s chance of survival & ability to reproduce • Increases fitness! Monarch Butterflies are poisonous to eat & they have special coloration to warn predators.

11. Fitness & Adaptations • Those individuals that are better able to survive & reproduce (have a higher fitness) pass on their morphological & physiological differences to their offspring! This bear’s cubs will inherit her adaptations!

12. Selective Pressure • Over time, populations are changed based on selective pressures of the environment. • Selective Pressure: any factor that makes it hard for some organisms to continue surviving, & rewards any advantage that some organisms may have been born with

13. Selective Pressures • Climate Changes • Food Supply Changes • Predators • Sexual Selection What was the selective pressure in your dot experiment?

14. Antibiotic Resistance What’s the selective pressure driving this population to evolve?

15. Let’s break it down… • Organisms produce more offspring than can possibly survive! • Those that do not survive do not reproduce, & therefore do not pass down their genes. • Each organism has different advantages & disadvantages in the struggle for existence. • Individuals best suited for their environment survive & reproduce most successfully.

16. Evolution by Means of Natural Selection • Natural Selection – “Survival of the Fittest” • Adaptations can be morphological, behavioral, or physiological, but they are NOT learned! • Adaptations may be an advantage in 1 environment & a disadvantage in another! • Natural selection only acts on heritable traits A mouse that has learned how to get into the pantry does not pass that down to its offspring in its genes! This is not an adaptation!