History of Life and the Origin of Species

1. History of Life and the Origin of Species Mrs. Stewart Honors biology Central Magnet School

2. Standards: • CLE 3210.5.3 – Explain how genetic variation in a population and changing environmental conditions are associated with adaptation and the emergence of new species.

3. Objectives (today, I will…) • Differentiate between biogenesis and spontaneous generation • Differentiate between Charles Darwin and Jean-Baptiste Lamarck • Explain the idea of “natural selection” and determine “fittest”

4. History of Life • Biogenesis: • All living things come from other living things • Spontaneous Generation: • Living things could arise from nonliving things

5. Redi’s experiment • Previous idea: Flies were created from rotten meat • Redi: Meat kept away from adult flies would not produce maggots

6. Spallanzani& Pasteur • Spallanzani – tried to disprove that microorganisms arose from a “vital force” in the air • Pasteur – improved spallanzani’s experiment to eliminate the flaw of “no air”

7. Ch. 15.1 – 15.2History of Evolution Mrs. Stewart Honors Biology Central Magnet School

8. What is Evolution? • Dictionary: • The gradual development of something; especially from a simple to complex form. • Text book: • Generally, in biology, the process of change by which new species develop from pre-existing species over time • Evolution of Dance

9. 18th Century Ideas • About living species: • About the Earth: • Uniformitarianism All species were permanent and unchanging. Earth was only a few thousand years old and unchanging. Idea by Charles Lyell that said geologic processes happed slowly over time and that some features of the Earth may take millions of years to form.

10. 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.

11. 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

13. 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

14. 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

15. 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.

16. 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

17. Hood Island Tortoise Pinta Island Tortoise What observations can YOU make about these species of land tortoise? Isabella Island Tortoise

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

19. 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

20. 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

21. 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 what to do for 25 years.

22. 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

23. Natural Selection Mrs. Stewart Honors biology Central Magnet School

24. 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

25. Standards: • CLE 3210.5.3 – Explain how genetic variation in a population and changing environmental conditions are associated with adaptation and the emergence of new species.

26. Darwin’s reasoning for Natural Selection • Overproduction – more offspring produced than can survive • 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 prevelant in the population.

27. 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?

28. 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

29. 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.

30. 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

31. Adaptations • Any inherited characteristic that increases an organism’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

33. Objectives (today, I will…) • Differentiate between biogenesis and spontaneous generation • Differentiate between Charles Darwin and Jean-Baptiste Lamarck • Explain the idea of “natural selection” and determine “fittest”

34. Evidence of Evolution Mrs. Stewart Honors Biology Central Magnet School

35. Standards: • CLE 3210.5.3 – Explain how genetic variation in a population and changing environmental conditions are associated with adaptation and the emergence of new species.

36. Descent with Modification • Over long periods of time, natural selection produces organisms with different structures, niches or occupy different habitats than their ancestors. • Each living species has descended, with changes, from other species over time. • Result: species today look/act different from their ancestors

37. Common Descent • Look back: Tigers, panthers and cheetahs all share a common ancestor • Look back further: you will find ancestors that these cats share with horses, dogs and bats. • Farther back: common ancestors of mammals, birds, alligators and fishes. • Logic: looking far enough back we should find the common ancestor for all living things

38. Common Descent

39. Homologous Structures & Vestigial Organs Fossil Records Evidence of Evolution Comparative Embryology Common Descent & Descent w/ Modifications

40. Fossil Records Fossils - preserved remains of ancient organisms Compare fossils from older layers and younger layers and show changes in species over time

41. Fossil Records • Compare fossils found around the world and we can infer when and where different organisms existed. • Fossils also provide evidence about the environment in which the organism existed and for which the organism adapted

42. Transitional Species • Fossil records show species which have features that are intermediate between those of hypothesized ancestors and later descendant species

43. Homologous Body Structures

44. Homologous Body Structures • The limbs of reptiles, birds and mammals (arms, wings, legs and flippers) vary greatly in form and function but are all constructed from the same basic bones. • Vestigial Organs – organs/body parts that were once used, but by natural or artificial selection, are no longer necessary

45. Vestigial Organs Appendix

46. Vestigial Organs • Hip bone in a whale

47. Vestigial Organs Tailbone in humans

48. Similarities in Embryology • The early stages, or embryos, of many animals with backbones are very similar. • Does this mean that a human embryo is ever identical to a fish, or a bird embryo? • NO • But, many embryos look especially similar during early stages of development.

49. Fish Salamander Tortoise Chicken Pig Man

50. Comparative Embryology • What do these similarities mean? • The same groups of embryonic cells develop in the same order and in similar patterns to produce the tissues and organs of all vertebrates.