1. HAPPY WEDNESDAY Bellwork: Write down only the bolded red portion and your answer. Two species of mice live in a field in the middle of East Texas. One mouse species is WHITE with BLACK spotting. The other is BROWN with WHITE spotting. After a year, the population of white mice has dramatically decreased, while the population of the brown mice has slightly increased. Why would this be happening?

2. Standard: (7E)Analyze and evaluate relationship of natural selection to adaptation. Essential Question:

3. Evolution: What is it?

4. Evolution: change in heritable traits of a population across generations (over time).

5. A gene pool is the total number of genes of every individual in an interbreeding population.

6. Evolution can also be defined as a change in the gene pool over time.

7. Something Important to Know: Theory: a well-supported scientific explanation that is subject to change. Law: a scientific fact. Evolution is a theory.

8. Evolution is called “the grand unifying theory of biology.” Evolutionary theory continues to change as new data are gathered and new ways of thinking arise.

9. What important contribution did Charles Darwin make to biology?

10. Charles Darwin: contributed more to our understanding of evolution than anyone else. Darwin traveled, made observations and collected evidence that led him to propose his revolutionary process in a book called Origin of the Species.

11. Mechanisms of Evolution (How does evolution happen?)

12. There are 5 factors that can affect the frequency of a gene in the gene pool. 1.Genetic Mutation 2.Non-random mating 3.Natural Selection 4.Small Population 5.Gene Flow

13. 1. Genetic Mutation: Changes in DNA that happen due to errors in replication, transcription, translation, or because of environmental factors. – The source of all new genes/traits in a population

14. If mutations are passed on to offspring (over generations), then evolution has occurred

15. 2. Non-Random Mating Not all mates are created equal. In many species, mates are not selected at random. Instead they are chosen for specific characteristics. Many organisms compete for mating rites. Strong and good-looking organisms are typically favored. This limits the size of the gene pool because only the genes of the mating individuals are passed to the next generation.

16. 3. Natural selection: the process by which randomly generated characteristics are selected for/against by nature in a consistent, non-random, orderly way. It is not seen directly, but only observed as changes in a population over a long time.

17. 3. Natural Selection survival of the fittest advantageous genes are passed on to the next generation while harmful genes are eliminated the driving force of evolution

18. Summary of Darwin’s Theory cont’d:  Other individuals that are not suited for their environment die or leave few offspring  This process called natural selection causes species to change over time  Species alive today are descended with modification from ancestral species (their ancestors)  This process by which diverse species evolved from a common ancestor unites all organisms on Earth into a single tree of life

19. Bunny Simulation If only one species is considered the "fittest", why do we still have so many variations among species. Why do some birds have very long pointy beaks, while other birds have short flat beaks?

20. Examples of natural selection

21. Why does natural selection happen?

22. Population size is limited by environmental resources

23. Fitness: the ability of an organism to survive and reproduce. Fitness is the result of adaptations.

24. Adaptation: any inherited characteristic that increases an organism’s chance of survival.

25. Successful adaptations: - enable organisms to become better suited to their environment - increase an individual’s ability to survive and reproduce. Humans have thousands of adaptations: large brain, opposable thumbs, excellent sensory organs, light, strong skeleton, etc.

26. Debrief Options Create a chart on the bunny simulation What are adaptations that can help the wolf survive? Quickwrite answering Essential Question.

27. Homework Take notes and summarize the youtube video “What is natural selection?” by Stated Clearly

28. What to do: 1.Check you grade in the back. 2.Figure out which of the assignments you need to make up. 3.Get the assignment. 4.When finished, turn it in to you class period tray. IF YOU HAVE NOTHING TO MAKE UP: Congratulations! You won a trip to space! You are going to Mars to study the organisms that live there. When you arrive you observe 2 new species. Using the basic characteristics of Mars, create the two species you encounter with adaptations that are appropriate for life on Mars. Write 5 sentences describing the organisms and draw a picture of them on Mars. Basic Characteristics of Mars: Diverse terrain, including: mountains, valleys, polar ice caps, deserts Atmosphere has clouds, thus rain The red color is due to blowing sand Has vegatation It is VERY cold.

29. Summary of Darwin’s Theory:  Individual organisms differ and some of these variations are heritable (passed on)  Organisms produce more offspring than can survive and many that do survive do not reproduce  Because more organisms are produce than can survive, they must compete for limited resources (food, shelter, etc)  Each unique organism has different advantages (good) and disadvantages (bad)  Individuals best suited to their environment survive and reproduce successfully  These organisms that survive pass their heritable traits to their offspring

30. Bellwork: Give 2 examples of natural selection

31. Science Fact of the Day: The diving bell spider is the only species of spider known to spend its entire life underwater.

32. I. Mechanisms of Evolution

33. Essential Question: How does evolution happen?

34. How does a small population affect evolution?

35. 4. Effects of Gene Pool Size A decrease in the size of a gene pool increases the speed of evolution and visa versa.

36. 4. Small Population 1.Bottleneck effect- when a large portion of a population dies causing a significant decrease in the size of the gene pool. 2.Founder effect- when a few individuals from a population leave and start another population in a different location. This also decreases the size of the gene pool in the new population.

37. Genetic Drift is a random change in the frequency of alleles in a population due to random sampling.

38. How can new genes enter a population?

39. 5. Gene Flow Gene flow is the movement of genes into or out of a population. a.Emigration- when individuals leave a population decreasing the size of the gene pool. b.Immigration- when individuals from a different population enter a new population and begin breeding. This increases the size of the gene pool.

40. Can evolution occur in patterns?

41. Gene pools can change in 3 different ways: a. Disruptive selection b. Stabilizing selection c. Directional selection

42. 1. Disruptive selection: individuals on the upper and lower ends of a distribution curve are more fit than organisms in the middle, curve becomes a U-shaped.

43. 2. Directional selection: when organisms at one end of the distribution curve have the highest fitness, shifts the curve in one direction.

44. 3. Stabilizing selection: when individuals in the middle of the distribution curve have the highest fitness, the curve does not move/change.

45. What is the difference between micro and macro evolution?

46. Changes in the frequency of a gene in the gene pool initially leads to microevolution. Microevolution refers to a small change in a population over a short amount of time. Many small changes eventually lead to macroevolution. Macroevolution refers to the sum total of many changes that transform organisms over a long period of time. Macroevolution leads to speciation or the creation of a new species. When an evolving population can no longer interbreed with the original population, a new species is formed.

48. Speciation: creation of 2 different species from 1 original species Macroevolution: total of many changes that transform organisms over a long period of time. Microevolution: small change over a period of time Changes in the frequency of a gene in a gene pool leads to

49. Mix-Freeze-Group I am going to survive! Because I have the best genes for my environment. I am HUGELY affected by genetic drift. I am VERY picky. I will only choose you, because your traits are most attractive to me. I am a mistake in the DNA sequence Natural Selection Small Population Genetic Mutation Non-Random Mating

50. Scenarios

51. 1.Amish people are required by their religion to only marry and have children with other Amish people.

52. 2. The DNA sequence in a bird is changed from ATT CCG TTG to TTA CCG TTG which changes the beak shape from long and thin to short and fat.

53. 3.Peppered moths are eaten by birds. The moth color varies from light to dark. Light colored moths can blend in with a nearby species of tree. In the 1800s factories released large amounts of soot, which changed the tree color, so the birds were able to more easily find the lighter moths instead of the darker moths.

54. 4. Northern elephant seals were hunted almost to extinction by people in the 1890s. The remaining population has reduced genetic variation.

55. 5. A lioness joins a new pride and has cubs with the male lion.

56. 6. A small group of birds flies from the mainland to an island and starts a new colony. (The birds never return to the mainland.)

57. Homework: “evidence of evolution” by stated clearly Take notes AND summarize