TOPIC : Evolution AIM : Explain the theory of Natural Selection.

1. TOPIC: Evolution AIM: Explain the theory of Natural Selection. Do Now: Take out the Punnett Square ditto and last night’s HW. HW: Ditto – Pedigree Chart Review (other side)

2. Cross a homozygous tall plant with a short plant. TT X tt Genotype Percentages: 100% heterozygous Phenotype Percentages: 100% tall T T t T t T t T t t T t

3. Cross two plants with hybrid round seeds. Rr X Rr Genotype Percentages: 25% homozygous dominant 50% heterozygous 25% homozygous recessive Phenotype Percentages: 75% round 25% wrinkled R r R R R R r R r r r r

4. Cross a short plant with a hybrid tall plant. tt X Tt Genotype Percentages: 50% homozygous recessive 50% heterozygous Phenotype Percentages: 50% tall 50% short t t T T t T t t t t t t

8. What is an adaptation? Inherited trait Favorable: improves an organisms chance of survival

9. Ex: Camouflage

10. Ducks are birds that have waterproof feathers. They live on a pond and on land.

11. Kangaroos • Habitat: Dry inland Australia, including deserts and grasslands • Adaptations: • They are able to go with out drinking as long as green grass is available and it adapts well to drought. • They can hop as fast as 40 mph (64 km).  They use this as their first line of defense.  • The tail serves as a balance when the animal leaps and as a prop when it stands.

14. Charles Darwin 1830’s Studies on Galapagos Islands (off South America’s west coast)

15. Darwin’s Model of Evolution

17. Darwin’s visit to the Galapagos Islands He observed a variety of life on the islands. Hypothesis: All organisms migrated from Central and South America. Species become adapted to their environments Evolved over time into different species

18. Natural Selection Organisms with favorable adaptations will survive, reproduce and pass on that trait to offspring. Organisms with unfavorable adaptations will not survive.

19. Main Points of Natural Selection

20. 1. Overproduction: species produce more offspring than can survive Better adapted will survive & reproduce

21. 2. Competition: organisms compete for limited resources Better adapted will survive & reproduce

22. 3. Variation: differences bw organisms in the same species

23. Ex: Polar bears with thicker fur • Darwin wasn’t able to explain where variations came from

25. 4. Survival Of the Fittest: Those most “fit” (have favorable adaptations) will survive & reproduce

26. 5. Speciation: formation of new species

30. Let’s summarize… • What islands did Darwin visit? • Where did Darwin think organisms on the Galapagos islands originally came from? • What are the main points to Darwin’s Theory of Natural Selection.

31. The diversity within the wild bird species in the diagram below can best be explained by which process? (1) natural selection   (3) ecological succession(2) asexual reproduction (4) mitotic cell division

32. Which concept would be correctly placed in box X? • use and disuse     • variation            • transmission of acquired traits • changes in nucleic acids

33. Which statement is not part of the concept of natural selection? • Individuals that possess the most favorable variations will have the best chance of reproducing. (2) Variation occurs among individuals in a population. (3) More individuals are produced than will survive. (4) Genes of an individual adapt to a changing environment

34. According to the theory of natural selection, why are some individuals more likely than others to survive and reproduce? • Some individuals pass on to their offspring new characteristics they have acquired during their lifetimes. • Some individuals are better adapted to exist in their environment than others are. • Some individuals do not pass on to their offspring new characteristics they have acquired during their lifetimes. • Some individuals tend to produce fewer offspring than others in the same environment.

35. Charles Darwin proposed that organisms produce many more offspring than can possible survive on the limited amount of resources available to them. According to Darwin, the offspring that are most likely to survive are those that  (1.) are born first and grow fastest  (2.) are largest and most aggressive  (3.) have no natural predators  (4.) are best adapted to the environment

36. Darwin's studies of finches on the Galapagos Islands suggest that the finches' differences in beak structure were most directly due to  (1.) acquired characteristics in the parent finches  (2.) the size of the island where the finches live  (3.) mating behaviors of the different finch species  (4.) adaptations of the finches to different environments

37. According to Charles Darwin, one factor that affects the evolution of a species is  (1.) variation due to genetic mutations  (2.) rapid fossil formation  (3.) survival of the fittest  (4.) exposure to environmental pollutants

38. How many people in this pedigree chart have the recessive trait? • How many people in this pedigree chart are carriers? • How many offspring are found in generation 2? • What is the chance of the individuals in generation 1 having a child with the recessive trait?

39. 1. How many individuals make up generation 2? 2. What are the genotypes of the individuals in generation 1? 3. How many individuals make up generation 3?

40. Gorillas • Habitat: Tropical forest • Adaptations: • Opposable thumb enables manipulation of objects; big toe also opposable for grasping. • Large and powerful arms used to break stalks or uproot vegetation while foraging. • High intelligence probably an adaptation for finding scarce or isolated fruit plants in the rain forest.

41. Cactus • Habitat: Dry deserts • Adaptations: • The spines serve a number of purposes in addition to protection from hungry and thirsty animals. • They provide shade, serve as a windbreak to prevent dehydration from dry winds, and help trap warm air close to the plant. • The root systems of cacti are very close to the surface of the soil, making it possible for them to take advantage of the slightest rain shower.