1. Intro to Evolution… Take out a sheet of blank notebook paper and a pen/pencil!

2. Introductory Activity… *You will be working in your rows for this activity. *I am going to hand a picture to the student at the end of the row. He or she will copy what they see in 30 seconds. *When I call time, he or she will pass their own drawing to the person in front of them. *The next person will draw what they see from the student behind them in 30 seconds. *When I call time, pass it along and repeat the process.

3. Let’s talk about the activity… What happened as the drawings progressed to the front of the row? What theory does this demonstrate? What is a theory? What are some causes of changes in the drawing from the original?

4. The Theory of Evolution – Change Over Time

5. EVOLUTION: the process of change over time Evolution is the idea that new species develop from earlier species by accumulated changes. This is also referred to as “descent with modification”.

6. Evolution is NOT… It is NOT a fact...it's a theory: a well supported testable explanation of something that occurred in the natural world.

7. How do these organisms move? These differences helped Darwin come up with his theory of evolution.

8. Jean Baptiste Lamarck *Use and Disuse Hypothesis (1809) No longer accepted- Behavior does NOT affect inheritance. *Inheritance of Acquired Traits

9. Lamarck’s Theories Tendency Toward Perfection – acquiring features that help them live more successfully in their environment –Ex: birds and flying Use and Disuse – Alter size and shape of their bodies –Ex: birds transform front limbs to wings Inheritance of Acquired Traits – pass on traits to offspring –Ex: weight lifter

10. Evaluation of Lamarck Is he on target? If not, where did he go wrong?

11. Charles Darwin 1831 Traveled to the Galapagos Islands where there was a variety of climates among the islands He observed much diversity in living things and how well suited they were to their environments.

12. Different Land Tortoises on Islands Hood Island – long neck – sparse vegetation Isabela Island – short neck – vegetation close to the ground Pinta Island – intermediate neck – What could this say about the environment?

13. Darwin observed variety within species and also studied artificial selection Led him to the theory of evolution by natural selection

14. What is natural selection? Struggle for existence leads to survival of the fittest (Natural Selection) The “fittest” are those with an inherited characteristic that makes it better suited to survive and reproduce. These characteristics are called Adaptations.

15. Adaptations! Inherited characteristic that increase an organism’s chance of survival Why are most animals in the artic white? –So they blend in with the snow and avoid being seen! Why do sharks have such sharp teeth? –It allows them to catch their prey! Why do elephants have such big ears? –To let heat escape their bodies so they can –stay cool!

16. Natural Selection results in changes in inherited characteristics of a population due to the environment, increasing the species’ fitness in that environment. These changes are observed over long periods of time and many generations.

17. Natural Selection Make-Believe Scenario Choose an animal and explain how its species might evolve over the next 1000 years as the earth changes.

18. Hutton and Lyell Studied geology and geological change Discovered that the Earth is millions of years old The process that changed Earth in the past are the same processes that operate in the present –Weathering of rock –Uplifting to form mountain ranges

19. Lyell’s Influence on Darwin If the Earth can change over time, might life change as well? Realized it would take many, many years for life to change in the way he suggested –This would only be possible if the Earth were extremely old!

20. Population Growth Malthus reasoned that if the human population continued to grow unchecked, sooner or later there would be insufficient living space and food for everyone. Darwin asked a couple of questions: –What causes death of so many individuals? –What factors determine which ones survive and reproduce and which ones do not?

21. Publication of “Origin of Species” Received a short essay from Alfred Wallace, which summarized the thoughts on evolutionary change that Darwin had NOW DARWIN HAD AN INCENTIVE TO PUBLISH HIS OWN WORK! He proposed a mechanism for evolution – called it natural selection!

22. Natural Selection Occurs Because of: 1. The Struggle for Existence 2. Survival of the Fittest 3. Descent with Modification 4. Genetic Variation 5. Overproduction of Offspring

23. INTRODUCTION TO EVOLUTION VIDEO http://www.pbs.org/wgbh/evolution/library/11/2/e_s_4.html

24. 5 parts of Darwin’s Theory of Natural Selection Genetic Variation – Ultimate source = MUTATIONS! Overproduction of Offspring Struggle for Existence Survival of the Fittest Descent with Modification

25. Organisms produce more offspring than can survive. Example: A frog can lay 200 eggs, yet not all eggs will survive to become adult frogs.

26. Struggle for Existence Members of each species compete regularly to obtain food, living space, ect. Prey – faster, better camouflaged, or better protected

27. Survival of the Fittest How well an organism is suited to its environment **Fitness – ability to change (adapt) in order to be able to survive and reproduce Is this always the strongest or the biggest organism????

28. Descent with Modification – Common ancestor and change over time in a population All living things are related due to common ancestors- Principle of “Common Descent”

29. Results of Evolution -- Speciation!! Speciation is the process that creates new species! A species is a group of organisms that can naturally interbreed and produce fertile offspring. The Liger--the offspring of a tiger and a lion. Tigers and lions are still considered separate species, because although they can produce offspring, the offspring is not fertile.

30. Evidence of Evolution A. Fossils – Mineralized remains or imprints of organisms from the past “Missing Links” – Intermediate fossils between groups of organisms Fossil record is not complete!

31. B. Geographic distribution of living species Species evolve differently in different environments Different species evolve similarly in the same type of environment

32. C. Amino Acid Sequences (DNA Evidence)– More closely related, more aa sequence similarities should be seen

33. D. Anatomy– Similar body structures that don’t necessarily have similar functions (Homologous Structures) Similar structures with reduced size and lesser function or no function (Vestigial Structures)

34. Evidence of Evolution -- Anatomical/Physiological Similarities Notice how there are similar bones and similar structures in humans, birds and whales! –Can you tell which is the bird and which is the whale?

35. Analogous Structures Serve the same function but are anatomically different. Serve as evidence that the organisms evolved independently

36. Vestigial Organs organ that serves no useful function over generations, they reduce in size

37. Evidence of Evolution -- Embryology! It is believed that all vertebrates evolved from a common ancestor. The genetic information that guides their development is nearly the same. That's why scientists can learn about human development by studying other organisms-- including zebrafish.

38. E. Embryonic Development – Similarities in development of embryos of organisms

39. Extinction! Extinction occurs when there are no members of a species left alive.

40. Evaluate the theory of evolution Strengths Weaknesses