2. Evolution Evolution- change in population over time

3. Evolution- Darwin Darwin father of modern evolutionary theory  Galapagos Islands  HMS Beagle

4. Darwin HMS Beagle Trip around the world

5. Scientists who influenced Darwin Lamarck- organisms change due to the pressures of their environment, traits are acquired develop characteristics passes offspring He proposed that by using or not using its body parts, an individual tends to develop certain characteristics, which it passes on to its offspring.

6. Scientists who influenced Darwin- Lamarck Example: Example: A giraffe acquired its long neck because its ancestor stretched higher and higher into the trees to reach leaves, and that the animal’s increasingly lengthened neck was passed on to its offspring.

7. Natural Selection Natural Selection- organisms with traits best suited to the environment survive have more offspring

8. Natural Selection Example: Peppered Moths during the Industrial Revolution

9. Natural Selection Extinction- permanent loss of a species 5 mass extinctions throughout history

10. Evidence for Evolution 1. Fossils 2. Comparative anatomy 3. Comparative embryology 4. Biochemistry 5. Genetic evidence 6. Direct evidence

11. Evidence for Evolution 1. Fossils mold or cast of organism left in rock, fossilized bone and teeth life becomes more complex over time record is incomplete

12. Evidence for Evolution Most complete fossil record is for the horse

13. Evidence for Evolution Relative dating- layers in rock bed used to date organisms Deeper is older, shallow is younger

14. tell when organisms lived in reference to other organisms older organisms show simpler body structure, while more recent organisms are more complex many fossils show strong similarities to existing organisms Evidence for Evolution

15. Radioisotope dating- uses half-life of element to estimate age of organism Carbon is used frequently

16. Evidence for Evolution phylogeny- description of the lines of descent of plants and animals as they lived from one to the next (how they are related)

17. Evidence for Evolution 2. Comparative Anatomy- the study of the structures of different organisms homologous parts modified structures among different groups of descendants

18. Evidence for Evolution Comparative Anatomy

19. analogous parts- structures in organisms that have no common origin but serve the same function Example: bird’s wing, bat’s wing and insect’s wing

20. Evidence for Evolution Comparative Anatomy vestigial organs- organs having no functions in the living organism Vestigial pelvis and femur in whalesVestigial toes in the horse

21. Evidence for Evolution Comparative Anatomy Vestigial spurs on a snake

22. Evidence for Evolution Comparative Anatomy What vestigial organ do we have????

23. Evidence for Evolution 3. Comparative Embryology the study of developing plants and animals

24. Evidence for Evolution Below is the pictures of embryos for a fish, human, rabbit, tortoise, and chicken. Can you guess which one is each type of organism? 1 2 3 4 5

25. Evidence for Evolution Comparative Embryology Here the pictures of the second set of development is added. Can you tell now? 1 2 3 4 5

26. Evidence for Evolution How about now? 1 2 3 4 5

27. Evidence for Evolution Comparative Embryology- The complete picture

28. Evidence for Evolution 4. Biochemistry comparison of DNA and proteins in the body Example: comparison of hemoglobin (blood protein) in human, chimp, and dog. Human and chimp hemoglobin more alike than dog

29. Evidence for Evolution The closer related the fewer differences in DNA and proteins

30. Evidence for Evolution 5. Genetic Evidence Mutations- mistakes in the genetic code Causes changes in populations over time

31. Evidence for Evolution 6. Direct Evidence Rapid Evolution Strains of bacteria becoming resistant to antibiotics Weeds and pesticides Insects and pesticide

32. Adaptations Adaptation- change in a species that makes it better suited to its environment Large feet for standing in the sand A hump to store nutrition during long trips or when food or water is scarce Calluses on the the knees to protect from abrasion Long eyelashes to protect their eyes from the sand when the wind is blowing Nostrils that close to keep sand out Fur inside the ears to protect inner ear from sand

33. Types of Adaptations Structural Changes in structure or anatomy Example: bird’s beak or claws Mimicry- a harmless species resembles a harmful one, predators learn to avoid both species Camouflage- species features blend in with the environment

34. Mimicry

35. Camouflage

36. Types of Adaptations Physiological Changes in chemical makeup Examples: digestion enzymes, snake venom, octopus ink

37. Types of Adaptations Behavioral Responses to the environment Example: bird migration

38. Mechanisms for Evolution Species- group of organisms that can interbreed AND produce viable offspring Populations evolve NOT individuals

39. Origin of a Species Common Misperception: Individuals Evolve Species evolve NOT individuals “And now there go the Wilsons!... Seems Like everyone’s evolving except us!”

40. Mechanisms for Evolution Gene pool- all the alleles for a trait in the population Over time gene pools shift to traits that are best suited to the environment Allelic frequency- the percent of any specific gene in a population Genetic Equilibrium- when the percentage of alleles in a population remains stable over time

41. Natural Selection acts on variation in a population 1. stabilizing – favors average individual 2. directional – favors one extreme variation 3. disruptive – favors both extremes of variation

42. Natural Selection acts on variation in a population Stabilizing selection Directional Selection Disruptive selection

43. Origin of Life on Earth Spontaneous generation- non- living materials can produce life, life could be created out of nothing, from the air

44. Disproving Spontaneous Generation

45. Origin of Life Biogenesis- living organisms only come from other living organisms

46. Origin of Cells Earth approximately 4.6 billion years old Beginning- earth’s atmosphere Hot, gases like CO 2 and nitrogen, little O 2 Gases helped to create the atmosphere

47. Origin of Cells 3.5 to 4 billion years ago Organic Molecules  Protocells  Prokaryotic cells (heterotrophs)  First simple autotrophs/producer  Eukaryotic cells  Multicellular organisms

49. Origin of a Species Speciation – formation of a new species, members of similar populations no longer interbreed

50. Origin of a Species Geographic Isolation Physical barrier divides population River, canyon, mtn. splits group Two species of squirrel split by the Grand Canyon

51. Patterns in Evolution Adaptive radiation – one ancestral species evolves into a number of species to exploit a number of habitats.

52. Patterns in Evolution Divergent evolution- one species evolves into two species with different characteristics (get more and more different from each other)

53. Patterns in Evolution Convergent evolution – distant or unrelated species evolve similar characteristics to take advantage of similar environments Example: fish and dolphin

54. Evolution