1. Theory of E v o l ut i o n

2. What is Evolution? Change over time The process by which modern organisms have descended from ancient organisms

3. 2 Competing Theories: D arwin and L a m ar c k

4. Darwin and Lamarck agreed on a few things… Life is still changing Living things become better suited to their environment All organisms are related Simple  Complex

5. Lamarck Organisms can change the shape or size of organs depending on how they use them –Most used body structures develop, unused structures waste away Acquired characteristicsAcquired characteristics could be inherited. –If an animal altered its body during its lifetime, that change will pass to offspring Organisms have a tendency toward perfection

6. Darwin

7. Charles Darwin “The Father of Evolution” 1831- sailed on the HMS Beagle to the Galapagos Islands.1831- sailed on the HMS Beagle to the Galapagos Islands. Studied many species of finches.Studied many species of finches. Published book in 1845:Published book in 1845: –“On the Origin of Species by Natural Selection”

9. Natural Selection Only certain individuals of a population reproduce The traits being selected contribute to fitness in the environment

10. Survival of the Fittest What is meant by fittest? How well you “fit” in your environment

11. Four main points… 1. More organisms are produced than can survive…leads to COMPETITION OVER RESOURCES1. More organisms are produced than can survive…leads to COMPETITION OVER RESOURCES Ex’s of resources…Ex’s of resources… –Water –Food –Habitat –Mates

12. 2. Individuals within a population vary, and some of these traits are heritable.

13. 3. Some variations are FAVORABLE (increase chances for survival/ reproduction) Male vs. Female CardinalsMale vs. Female Cardinals Male color attracts female= reproductive advantageMale color attracts female= reproductive advantage

14. 4.Better adapted individuals survive and reproduce These are the individuals that will pass on their genes to the next generation.These are the individuals that will pass on their genes to the next generation. This can change the GENE POOL:This can change the GENE POOL: –Includes all the genes of every reproductive member of a population Favorable heritable traits become more common in future generations and unfavorable heritable traits become less common.Favorable heritable traits become more common in future generations and unfavorable heritable traits become less common.

15. What The theory of evolution IS NOT!!! It does NOT occur in INDIVIDUALS…only populations!It does NOT occur in INDIVIDUALS…only populations! It does NOT happen quickly…the Earth has a Looooooong history!It does NOT happen quickly…the Earth has a Looooooong history! It does NOT explain how life came to be on Earth, just how it evolved after it was here.It does NOT explain how life came to be on Earth, just how it evolved after it was here. It does NOT have any driving force except the competition for limited resources.It does NOT have any driving force except the competition for limited resources.

16. Lamarck - why was he wrong?? –Lamarck did not know how traits were inherited –He did not know that an organism’s behavior has no effect on the traits it passes down –Acquired characteristics are not passed on to offspring –Organisms do not get what they "need" through "inner wants" or through "use and disuse” Individual intentions do not play a role. –Instead, the organisms well suited survive and reproduce while those ill suited die