Bell Work

1. Bell Work • Pick up today’s note page • Define evolution

2. Introduction to Evolution and the Origin of Life Mrs. Stewart Biology Stewarts Creek High School

3. Standards: • CCSS ELA 9-10.2 • I can trace the historical development of the theory of evolution • I can summarize the evidence for the theory of evolution • CCSS ELA 9-10.8 • I can critique and evaluate competing evolutionary arguments based on scientific knowledge, empirical evidence and logical arguments regarding relevant factors.

4. Can You… • Define evolution • Differentiate between biogenesis and spontaneous generation • Differentiate between Charles Darwin and Jean-Baptiste Lamarck • Explain the idea of “natural selection” and determine “fittest”

5. Choose… • But choose wisely. • Decide which partner is the bird and which is the cat.

6. Scientific Theory • Theory - a well-substantiated explanation of some aspect of the natural world, based on a body of facts that have been repeatedly confirmed through observation and experiment.

7. How did it all start? • Abiogenesis: • The process by which life arises from non-living matter, such as organic compounds • Happened on earth approx. 3.8 - 4.1 billion years ago in the ocean • Enough organic compounds bound together and were able to conduct energy processes more efficiently until life was created

8. Early Beliefs of How New Life Formed • Abiogenesis / Spontaneous Generation:Living organisms could arise from nonliving matter • Example: Cheese wrapped in a rag and left in a corner would produce mice • Disproven by Redi and Pasteur • Biogenesis: • All living things come from other living things

9. Miller/Urey • Stanley Miller and Harold Urey (1950s) • simulated early earth conditions in the lab and created a “spark” • created amino acids • www.ucsd.tv/miller-urey/

10. Archaebacteria • The earth’s earliest life forms were prokaryotes

11. Endosymbiosis • Where/how did mitochondria get their own DNA? • How did chloroplasts become so specialized? • Theory of Endosymbiosis: • Aerobic prokaryotes were engulfed by eukaryotic cells evolved into mitochondria (which perform aerobic respiration) • Photosynthetic prokaryotes were engulfed by plant cells and evolved into chloroplasts (where photosynthesis occurs)

12. How did we go from bacteria to mammals?Evolution

13. What is Evolution? • Evolution of Dance

14. Evolution • The process of changein all forms of life over generations • In general: how new species develop from preexisting species

15. What does it explain? • Does not attempt to explain the origin of life • Does explain how the most basic early life forms became the complex ecosystem we know today

16. Cats • Define evolution for your bird

17. Jean-Baptiste Lamarck • French Naturalist • 1809 • Lamarck’s Hypothesis: by selective use or disuse of organs, organisms acquire or lose certain traits. These traits could then be passed on to their offspring. • Lamarck believed over time, this process led to change in a species.

18. Lamarck’s Hypothesis 1. Tendency toward perfection - All organisms have an innate tendency toward complexity and perfection, so they are continually changing to be more successful in their environment 2. Use and disuse - Organisms can alter their bodies/organs by use or disuse 3. Inheritance of acquired traits - Organisms can pass on those altered body parts/organs to the offspring

19. Lamarck’s Hypothesis

20. Birds • What did Lamarck get right?

21. Cats • What did Lamarck get wrong?

22. Lamarck the Loser • First to develop a hypothesis of evolution • First to realize organisms adapt to their environment • But, Behavior has no effect on inheritable characteristics

23. Charles Darwin • 1809 – 1882 • Naturalist – study of nature and the natural world • Sailed on the HMS Beagle in 1831 • Every time the ship docked, Darwin went ashore to collect plant and animal specimens

24. Darwin’s observations piqued his interest in the diversity of life he observed. • Darwin even found evidence that suggested species once present on earth had vanished. • Researchers today speculate that 99.9% of all species that ever inhabited earth are now extinct.

25. Galapagos Islands • The islands were close together, but had very different climates • Smallest and lowest islands = hot, dry & barren • Hood Island = sparse vegetation • Higher islands had greater rainfall and a different assortment of plants/animals • Isabella Island = rich vegetation • Land Tortoise shell shapes could be used to identify which island it inhabited

26. Hood Island Tortoise Pinta Island Tortoise What predictions can YOU make about the island environment for each tortoise? What observations can YOU make about these species of land tortoise? Isabella Island Tortoise

27. Hood Island Tortoise Pinta Island Tortoise Which island would you predict has only low-lying vegetation? Isabella Island Tortoise

28. Darwin’s Idea • Darwin observed that the plants and animals varied noticeably among the different Galapagos Islands. • However, Darwin wondered if animals living on different islands had once been members of the same species– originating from the same South American ancestor

29. Darwin’s Finches • Darwin observed many different types of “finch” and noticed several different beak shapes. • Why? • He began to notice different shaped beaks were “adaptations” for different food sources

30. Religion’s Role • Darwin was a devout Catholic • He knew that his ideas, based on what he observed would provoke the catholic church • He debated over whether or not to publish his results for 25 years.

31. Darwin’s Theory –Descent With Modification The Origin of Species by Means of Natural Selection – 1858 • Every species – living or extinct – descended by reproduction from preexisting species • AND • Species must be able to change over time

32. Sources of Genetic Variation That Lead to Evolution • Sexual Reproduction • Crossing Over • Random Independent Assortment of Chromosomes • Mutations

33. Natural Selection

34. Review What was Lamarck’s hypothesis? What did Darwin believe? Inheritance of acquired traits Species changed as environment changed – adaptation and survival of the fittest

35. Standards: • CCSS ELA 9-10.2 • I can trace the historical development of the theory of evolution • I can summarize the evidence for the theory of evolution • CCSS ELA 9-10.8 • I can critique and evaluate competing evolutionary arguments based on scientific knowledge, empirical evidence and logical arguments regarding relevant factors.

36. Objective (Today I will…) • Explain the idea of “natural selection” and determine “fittest” • Examine how adaptations help animals survive better

37. Darwin’s reasoning for Natural Selection • Overproduction – more offspring are produced than can survive due to competition for resources • Genetic Variation – within a population, individuals have different traits. New traits may appear spontaneously. • Struggle to survive – constant competition may cause some variations/traits to be advantageous • Differential Reproduction – Organisms with the best adaptations will survive and reproduce, thus the advantageous adaptations will become most prevalent in the population.

38. Evolution by Natural Selection • Struggle for existence – each member of a species competes regularly for food, living space and other necessities of life. • main needs: Food, water, living space and ability to reproduce • Who wins?

39. Think – Pair – Share • How can we describe Natural Selection in just 4 words?

40. Survival of the Fittest • How well suited an organism is to it’s environment • Does fittest mean strongest? • Does fittest mean in the best shape? • Fitness – the ability of an individual to survive and reproduce • The result of adaptations

41. What determines fitness? • The Environment! • Anything that helps the organism survive and reproduce better increases an organisms fitness

42. Fitness leads to evolution

43. Change in Allele Frequencies • Natural selection on single-gene traits can lead to a change in allele frequencies and thus to evolution • Example: Red lizards are more visible; black lizards warm faster which allows them to be more active, sooner.

44. Fitness leads to evolution • Peppered Moth evolution • Peppered moth virtual lab

45. Survival of the Fittest • Fittest – the individuals most capable to survive and reproduce for multiple generations • The traits selected as the most useful for survival and reproduction are determined by the organisms environment • Natural Selection accounts for Descent with Modification as species become better adapted to different environments.

46. Birds • Explain to your cat how the environment can determine fitness – use a specific plant or animal as an example. (Not one Mrs. Stewart gave you)

47. What is a Population? • A group of organisms of the same species, that live in the same area, AND that interbreed

48. Adaptation vs. Acclimatization • Adaptation - Changes in traits in populations over time • Example: White moth population becoming a black moth population after 5 generations. • Acclimatization – individual organism changes physiologically • Example: growing thicker fur in winter

49. Adaptations • Any inherited characteristic that increases an organism’s (and population’s) ability to survive and reproduce • Anatomical or structural characteristics • Porcupine quills - protection • Longer necks in giraffes – find food • Physiological processes • How a plant performs photosynthesis • Instinctual Behaviors • Hunting in packs • Living in burrows