DO NOW – Tell your table: What adaptations do caribou have to help them live at the North Pole?

1. DO NOW – Tell your table: What adaptations do caribou have to help them live at the North Pole?

3. Chapter 5: The Evolution of Living Things

4. Evolution Evolution – change of species over time.

5. Evidence for Evolution #1 Fossils • Fossil –a remain or imprint of once living organisms • Fossil Record- A historical sequence of life through fossils. • Proof of Evolution: Fossil record shows how the • characteristics of • some species have • changed over time. • Ex.  dog to a horse

6. Evidence for Evolution #1 Fossils (Continued) • One of the few animals for which we have a fairly complete evolutionary record is the horse. • This is because all the main stages of the evolution of the horse have been preserved in fossil form. • Over 60 million years, the horse evolved from a dog-sized creature that lived in rainforests into an animal adapted to living on the plains & standing up to 2 meters high.

7. Evidence for Evolution #2 Homologous Structures • Homologous Structures - Body parts that are similar in related animals. Proof of Evolution: The similar structures show that we must have a commonancestor!

8. Evidence for Evolution #3 Vestigial Structures • Vestigial structures- structures present in modern day organisms but are not even used. Proof of Evolution: They are remnants of once useful structures, so they may have been useful to our ancestors.

9. Example: The pelvic bones in the baleen whale show structural changes over time. Evidence for Evolution #3 Vestigial Structures

10. Evidence for Evolution #4Molecular Biology • Molecular Biology – The more closely related the species are to each other, the more similar the DNA is! • Proof of Evolution: If 2 species have DNA in common, then they must have a common ancestor! • Similar species of organisms have more common DNA than do organisms that are more different

11. gorilla human chimpanzee siamang gibbon orangutan

12. Can you tell which of these is human?

13. Evidence for Evolution #5 Fetal Similarities • Fetal Similarities:The unborn offspring of many species resemble each other. • Proof of Evolution: There must have been a common ancestor.

14. How Do Living Things Evolve?

15. Charles Darwin’s Theory

16. Charles Darwin • 1831- Charles Darwin took the British naval ship called The HMS Beagle, which sailed to the Galapagos Islands. • He collected thousands of plants and animal samples and kept detailed notes of his observations.

17. Charles Darwin Observed Finches • Probing bill • Insect eater • Feeds in trees • Probing bill • Insect eater • Uses twig to probe insects from cactus • Grasping bill • Insect eater • Feeds in trees • Crushing Bill • Cactus seed eater He made careful notes about the Finches on different islands… • Differences in their beak shapes. • What they ate. • How they differed from each other as well as from Finches in the surrounding areas!

19. Darwin Studied Fossils Darwin studied fossils of animals he had never seen before. • He observed differences between modern day species and extinct species.

20. Darwin Observed Tortoises The tortoises on each of the Galapagos Islands had different characteristics. • Examples: Color, Size, Shape, Beak shape

21. Darwin talked to farmerswho used selective breeding. Darwin Interviewed Farmers • Selective Breeding:occurs when desirable traits are chosen by farmers to make sure that these traits are passed down to the next generation. • Example: Juicy fruits, meatier chickens, higher milk producing cows, etc.

22. Darwin’s Questions Darwin was puzzled by: • Why are the animals and plants that live or lived in one area different from the ones that live or lived in other areas? • Were they once related? • How did they change?

23. Darwin’s Conclusions • This led him to publish his book called: • On the Origin of Species by Natural Selection

24. Darwin wrote about his theory on how species change over time called: “The Theory of Natural Selection” Darwin’s Book • This is a 4 part theory that states the organisms that are better adapted to their environment survive and reproduce more successfully than less well adapted organisms do.

25. Darwin’s theory part 1 Overproduction Organisms have more offspring than can possibly survive.

26. Darwin’s theory part 2Inherited Variation • Variations are caused by mutations. • Mutation - random changes in our DNA that cause changes. Some of these changes are bad, some are neutral, & some are good. • If it is bad organism is less likely to mate & pass down the gene. The organism dies along with the mutation that made it less fit. • If it is neutral,  nothing happens. This is what most mutations are. • If it is good organism is more likely to survive and pass down the gene to their offspring.

27. Darwin’s theory part 3Struggle to Survive (Competition) • A natural environment does not have enough resources to keep all offspring alive. • Offspring have to compete for the following: Food, water,shelter, mates,land, etc. • Some variations give them an advantage and makes them more likely to survive. • A variation that makes an organism more likely to survive and reproduce is called: adaptation. • Examples: physical structures, behaviors for finding food, mating, migrating.

28. Darwin’s theory part 4Successful Reproduction • Individuals who survive are more likely to successfully reproduce and pass on the variations that made them more successful. • Also known as: “Survival of the Fittest”

29. PRACTICE:Look at each of these organisms. Determine how Darwin would explain how they got their characteristics.

30. How did the giraffe get a long neck?

31. How did the giraffe get a long neck? Overproduction – lots of giraffes are born Inherited Variation - Some giraffes are born with long necks, some are born with short necks. Struggle to Survive - The giraffes with long necks can reach leaves on trees better. The giraffes with short necks can’t reach leaves, so they will die. Successful Reproduction - The giraffes with longer necks survive and reproduce and pass the long necks on to their offspring.

32. How did the polar bear get white?

33. How did the polar bear get white? • Overproduction – Many polar bears are born. • Inherited Variation - Some polar bears are whiter than others. • Struggle to Survive- The bears that are more white can be camouflaged (protected from predators, hidden from prey) better in the snow. The bears that aren’t as white will die from predators or starvation. • Successful Reproduction - The bears that are whiter survive, reproduce, and pass the white fur on to their offspring.

34. How did the cheetah get fast?

35. How did the cheetah get fast? • Overproduction – many cheetahs are born. • Inherited Variations - Some cheetahs are faster than others. • Struggle to Survive- The faster cheetahs are better at getting prey and escaping predators. The slower cheetahs die. • Successful Reproduction -The faster cheetahs survive, reproduce, and pass their speed on to their offspring.

36. How did cacti get spines?

37. How did cacti get spines? • Overproduction – Many cacti are produced. • Inherited Variation - Some cacti have spines and some do not. • Struggle to Survive- The cacti with spines are protected from animals that want to eat them. The cacti without spines get eaten by animals and die. • Successful Reproduction - The cacti that survive reproduce and pass the spines on to their offspring.

38. How did elks get antlers?

39. How did elks get antlers? • Overproduction – lots of baby elk are born. • Inherited Variation - Some elk have antlers and some do not. • Struggle to Survive - The elk without antlers can’t defend themselves and don’t impress female elks. The elk that don’t defend themselves or mate die and they do not reproduce. • Successful Reproduction - The elks with antlers survive and impress females, so they reproduce, passing antlers on to their offspring.

40. How did flowers get bright colors?

41. How did flowers get bright colors? • Overproduction – lots of flowers are produced • Inherited Variation - Some flowers have brighter colors than others. • Struggle to Survive- The flowers with bright colors are attractive to birds and bees and get pollinated. The flowers that are not bright are attractive and do not get pollinated. They won’t reproduce. • Successful Reproduction - The bright flowers survive and pass their bright colors on to their offspring.

42. How did sharks get sharp teeth?

43. How did sharks get sharp teeth? • Overproduction – lots of sharks are born. • Inherited Variation - Some sharks have sharp teeth, and some have dull teeth. • Struggle to Survive- The sharks with dull teeth can’t attack pray and eat as well as sharks with sharp teeth. They will die. • Successful Reproduction - The sharks with sharp teeth will survive, reproduce, and pass their sharp teeth on to their offspring.

44. Video Clip “Whale Evolution” http://www.youtube.com/watch?v=8cn0kf8mhS4

45. http://www.zo.utexas.edu/faculty/antisense/tree.pdf

46. Generation Time • Populations change due to the environment • Generation Time - the period between the birth of one generation and the birth of the next one. • Species with short generation times adapt quickly. • Species - a group of organisms that can mate with one other to produce fertile offspring. • EX: red eyed tree frogs mate with red eyed tree frogs to make more red eyed tree frogs

47. Recap Questions 1. What is the change of species over time? Evolution Fossils, homologous structures, vestigial structures, molecular biology, fetal similarities 3. What it is called when famers select desirable traits to breed in order for those traits to be passed down to the next generation? Selective Breeding 4. What is the theory that states the organisms that are better adapted to their environment survive and reproduce more successfully than less well adapted organisms do. The Theory of Natural Selection 2. What are the five pieces of evidence for evolution?

48. Recap Questions Overproduction, Inherited Variation, Struggle to Survive, Successful Reproduction Mutations • Adaptation • Food, water, shelter, mates, land 5. What are the four parts of the theory of natural selection? 6. What are variations caused by? • A variation that makes an organism more likely to survive and reproduce is called what? 8. Offspring have to compete for the following 5 things:

49. Formation of New Species Speciation- the formation of a new species as a result of natural selection.

50. 3 Steps to Speciation 1. Separation 2. Adaptation 3. Division