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Chapter 15

Chapter 15. Changes Over Time. Chapter Intro-page 392. Chapter 15 The Theory of Evolution. Why its important: Evolution is the key concept to understanding biology It explains the ____________ of species and predicts ______________. diversity. changes. New Vocabulary.

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Chapter 15

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  1. Chapter 15 • Changes Over Time

  2. Chapter Intro-page 392 Chapter 15 The Theory of Evolution Why its important: • Evolution is the key concept to understanding biology • It explains the ____________ of species and predicts ______________ diversity changes

  3. New Vocabulary • Artificial selection • Natural selection • Mimicry • Camouflage • Homologous structure • Analogous structure • Vestigial structure • Embryo

  4. 15.1 Section Objectives – page 393 Section Objectives: • Summarize Darwin’s theory of natural selection. • Explain how the structural and physiological adaptations of organisms relate to natural selection. • Distinguish among the types of evidence for evolution.

  5. Section 15.1 Summary – pages 393-403 • As soon as scientists started studying _______ and dating _________, they started suspecting that species change over time, or __________ • Recall that evolution is the gradual _________ in a species through ______________ over time fossils rock evolve change adaptations

  6. Review? • What is an adaptation? Something that allows an organism to survive; A favorable trait that is inherited

  7. Section 15.1 Summary – pages 393-403 • Many explanations about how species evolve have been proposed… • but the ideas first published by ________ ___________ are the basis of modern evolutionary theory. Charles Darwin

  8. Section 15.1 Summary – pages 393-403 Charles Darwin • It took Darwin _________ to develop his theory of evolution. years • Began his studies in 1831 when he was 22 years old • took a job as a _____________ on the English ship ______________, which sailed around the world on a five-year scientific journey. naturalist HMS Beagle

  9. Section 15.1 Summary – pages 393-403 Darwin on HMS Beagle

  10. Section 15.1 Summary – pages 393-403 • As the ship’s naturalist, Darwin studied and collected ____________ and ___________ specimens at every port along the route. • On the Galapagos Islands, Darwin studied many species that are ____________ to the islands but ____________ to species elsewhere plant animal unique similar

  11. Example What organism does this look like? While they normally live in ____________, this one from the Galapagos is different because it eats _________ from the ocean and has large _________ to help it cling to slippery rocks An iguana deserts algae claws

  12. Section 15.1 Summary – pages 393-403 • These observations led Darwin to consider the possibility that through ____________ adaptations species can _________ over time. • For the next two ___________, Darwin continued to refine his explanation for how species change over time inherited change decades

  13. Section 15.1 Summary – pages 393-403 • Darwin knew that many species produce _______ numbers of offspring. large • He also knew that such species had not ___________ Earth. overrun

  14. He also realized that traits within a population ____________ • These individuals struggle or ___________ with one another • Only some individuals ___________ the competition and produce ____________ vary compete survive offspring

  15. Section 15.1 Summary – pages 393-403 • During Darwin’s time, scientists were familiar the process of _______________ selection • That is…breeding organisms with specific traits in order to produce offspring with identical traits • Examples • Breeding black poodles • Breeding red peppers artificial

  16. Section 15.1 Summary – pages 393-403 • Darwin hypothesized that there was a force in nature that worked like artificial selection. • He called this force __________ selection Natural

  17. Section 15.1 Summary – pages 393-403 • Natural selection is a mechanism for ____________ in populations. change • It occurs when organisms with favorable variations… • ___________ • ___________ • and ______ on their adaptations to the next _____________. survive reproduce pass generation

  18. Section 15.1 Summary – pages 393-403 • Natural selection is also called survival of the _____________ • “Fit” does not necessarily mean the strongest and the fastest… • “fit” refers to which organisms are best adapted to their ________________ fittest environment

  19. Natural Selection For example, hummingbirds move their wings very quickly to hover and acquire nectar… • Which type of hummingbird would be more successful over time…small or large? small

  20. data • The theory of evolution is a scientific theory because _________ supports it • There are ____ main types of data or ______________ that support the theory of evolution 6 evidence

  21. Evidence #1 - ______________________ Structural Adaptations • Develop over _______________ of years • Example: Different kinds of rats millions African Rock Rat Mole Rat

  22. How are these rats different? Below Ground Above ground Blind Longer tail Long Claws

  23. Over time, blind rats may have evolved because their vision had no __________ advantage survival

  24. Section 15.1 Summary – pages 393-403 • Some other structural adaptations are subtle • __________________ • Enables one species to look like another species • __________________ • Enables species to ____________ with their surroundings mimicry camouflage blend

  25. Section 15.1 Summary – pages 393-403 Mimicry • The harmless syrphid fly mimics the appearance of a yellow jacket • Can you tell them apart? • What will you do when you see either of them? no Avoid them

  26. Section 15.1 Summary – pages 393-403 Camouflage • How is the frog blending in to its environment? • Will it be easy for predators to find it? It is the same color no

  27. Section 15.1 Summary – pages 393-403 Physiological Adaptations Evidence #2 _________________________ • Changes in an organism’s _____________ processes • Occur __________________ metabolic rapidly • Observed in smaller organisms that reproduce _______________, like bacteria, insects, and weeds quickly

  28. Why might organisms with a short life span evolve more quickly than organisms with a longer life span? They pass on traits faster

  29. Section 15.1 Summary – pages 393-403 Example: Antibiotic Resistance in Bacteria Non-resistant bacterium Antibiotic Resistant bacterium The bacteria in a population ________ in their ability to resist antibiotics. When the population is exposed to an antibiotic, the _____________ bacteria survive, while many of the non-resistant bacteria ________ The resistant bacteria live and ___________ more resistant bacteria. vary produce resistant die

  30. Section 15.1 Summary – pages 393-403 Evidence #3 - ____________________ Fossils • Provide a ___________ of early life and evolutionary history • This record, though, is _______________ record incomplete

  31. Section 15.1 Summary – pages 393-403 Fossils Camel Evolution Oligocene 33 million years ago Miocene 23 million years ago Eocene 54 million years ago Paleocene 65 million years ago Age Present Organism Skull and teeth Limb bones

  32. Section 15.1 Summary – pages 393-403 Evidence #4 - ____________________ Anatomy • Structural features with a common evolutionary origin are called _______________ structures. homologous • Homologous structures can be similar in… ____________ and ____________ Crocodile forelimb structure function Bird wing Whale forelimb

  33. Section 15.1 Summary – pages 393-403 • The body parts of organisms that do not have a common evolutionary origin but are similar in _____________ are called _____________ structures. • Ex: Insect wing and bird wing function analogous

  34. Section 15.1 Summary – pages 393-403 • A body structure in a present-day organism that no longer serves its original purpose, but was probably useful to an ancestor is called a __________________ structure • Examples • Human appendix • Snakes with feet • Whales with pelvic bones • Ostrich wings vestigial

  35. Section 15.1 Summary – pages 393-403 Evidence #5 - ____________________ Embryology • An embryo is the _________ stage of growth and development of both plants and animals. earliest • The embryos of a fish, a reptile, a bird, and a mammal have a _____ and pharyngeal ___________ (gills) tail pouches Pharyngeal pouches Pharyngeal pouches Tail Tail Reptile Bird Mammal Fish

  36. Section 15.1 Summary – pages 393-403 • It is the _________ features in the young embryos that suggest evolution from a distant, ________________ ancestor. shared common Pharyngeal pouches Pharyngeal pouches Tail Tail Reptile Bird Mammal Fish

  37. Section 15.1 Summary – pages 393-403 Evidence #6 - ____________________ Biochemistry • Compares the biochemical molecules of organisms • ____________ • ____________ • ____________ DNA or RNA enzymes proteins

  38. Section 15.1 Summary – pages 393-403 • When compared, which two types of organisms have the least amount of differences in a protein called cytochrome c? • The most different? Two orders of mammals Algae vs. animals Biochemical Similarities of Organisms Percent Substitutions of Amino Acids in Cytochrome c Residues Comparison of Organisms 5 and 10 Two orders of mammals Birds vs. mammals 8-12 Amphibians vs. birds 14-18 Fish vs. land vertebrates 18-22 Insects vs. vertebrates 27-34 Algae vs. animals 57

  39. Even though evolution has much data to support it, it has one major flaw… • Most of it’s data cannot be observed directly because evolution takes too ___________ • If you cannot observe the data in your life time, it is called ___________ evidence long indirect

  40. One type of data that we talked about does occur quickly… • Which one was it? • This type of data is called ________ evidence Physiological adaptations direct

  41. 15.1 Section Objectives – page 393 Objective 1 • Summarize Darwin’s theory of natural selection. • It occurs when organisms with ________________ variations ___________, ________________, and ______________ on their adaptations to the next _________________ survive favorable reproduce pass generation

  42. 15.1 Section Objectives – page 393 Objective 2 • Explain how the structural and physiological adaptations of organisms relate to natural selection. • Structural: blind mole rat? • Physiological: antibiotic resistance in bacteria? Sight was not necessary so it was not selected for Resistant bacteria survive and reproduce

  43. 15.1 Section Objectives – page 393 Objective 3 • Distinguish among the types of evidence for evolution. • Anatomy • Embryology • Fossils • Biochemistry Homologous, vestigial, analogous structures Shared embryonic structures indicate closer relationships Study rock layer patterns Look for similarities in proteins, DNA, RNA

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