1. December 8, 2010 Notes - Chapter 15 Evolution Notes - Chapter 15 Evolution HW. – outline Ch. 16 notes HW. – outline Ch. 16 notes Chapter 15 and 16 due Thursday Chapter 15 and 16 due Thursday

2. Definitions Evolution = change over time Evolution = change over time –The process By Which Modern Organisms Have Descended From Ancient Organisms Theory Theory –A Well Supported, Testable Explanation of Phenomena That Have Occurred In The Natural World

3. Voyage of the Beagle During His Travels, Darwin Made Numerous Observations And Collected Evidence That Led Him To Propose A Revolutionary Hypothesis About The Way Life Changes Over Time

4. Darwin’s Observations Patterns of Diversity Patterns of Diversity –Unique Adaptations –Species Not Evenly Distributed »Australia, Kangaroos but No Rabbits »S. America, Llamas

5. Darwin’s Observations Living Organisms & Fossils Living Organisms & Fossils –Fossils »Resembled living organisms »Where Had These Species Gone? »How Were They Related To Living Species?

6. The Galapagos Islands Small Group of Islands 1000 km West of S. America Small Group of Islands 1000 km West of S. America –3 Very Different Climates –Animals On Islands Unique to the island »Tortoises »Iguanas »Finches

9. Who else? An Ancient, Changing Earth: Hutton & Lyell Helped Scientists Recognize That Earth Is Many Millions of Years Old, And The Processes That Changed Earth In The Past Are The Same Processes That Operate In The Present

10. Hutton’s Theory of Geological Change James Hutton James Hutton –Described The Geological Forces That Have Changed The Earth Over Millions of Years »Sedimentary »Volcanic »Displacement »Erosion

11. Lyell’s Principles of Geology Explained Geological Processes That Shaped The Earth Explained Geological Processes That Shaped The Earth –Helped Darwin Understand Sea Shells In The Andes Mountains At 12,000+ Feet –Expanded Earth’s Age

12. Lamarck’s Theory of Evolution Jean-Baptiste Lamarck Jean-Baptiste Lamarck –One Of First Scientists To Understand That Change Occurs Over Time –Changes Are Adaptations To Environment –Almost On The Right Track, Almost

13. Lamarck’s Theory of Evolution Key Concept Key Concept –Lamarck Proposed That By Selective Use Or Disuse Of Organs, Organisms Acquired Or Lost Certain Traits During Their Lifetime. These Traits Could Then Be Passed On To Their Offspring. Over Time This Led To New Species.

14. Lamarck’s Theory of Evolution Tendency Toward Perfection Tendency Toward Perfection –Organisms Are Continually Changing and Acquiring Features That Help Them Live More Successfully In Their Environment »Bird Ancestors Desired To Fly So They Tried Until Wings Developed

15. Lamarck’s Theory of Evolution Use & Disuse Use & Disuse –Organisms Could Change The Size Or Shape Of Organs By Using Them Or Not Using Them »Giraffe’s Necks

16. Lamarck’s Theory of Evolution Inheritance Of Acquired Traits Inheritance Of Acquired Traits –Traits Acquired During Ones Lifetime Would Be Passed To Offspring (applies to ALL organisms) –Ex. If you spent much of your life building muscles then your offspring would inherit big muscles too!

17. Lamarck’s Theory of Evolution Lamarck’s Errors Lamarck’s Errors –Did Not Know About Inheritance of Traits »Genes Are Not Changed By Activities In Life »Change Through Mutation, Occurs Before An Organism Is Born

18. Population Growth Thomas Malthus Thomas Malthus –Economist –Observed Babies Being Born Faster Than People Were Dying »Population vs. Food Supply

19. Population Growth Key Concept Key Concept –Malthus Reasoned That If The Human Population Continued To Grow Unchecked, Sooner or Later There Would Be Insufficient Living Space & Food For Everyone

20. Population Growth Darwin Realized Malthus’s Principles Were Visible In Nature. Darwin Realized Malthus’s Principles Were Visible In Nature. Plants & Animals Produce Far More Offspring Than Can Be Supported. Plants & Animals Produce Far More Offspring Than Can Be Supported. –Most Die –If They Didn’t – Earth Would Be Overrun

21. Population Statistics in the United States From 1900 to 1990 1900191019201930194019501960197019801990 Live births per thousand32.330.127.721.319.424.123.718.415.915.6 Deaths per thousand17.114.713.011.310.89.69.5 8.88.7 Number of births over deaths15.215.414.710.08.614.514.28.97.16.9 Life expectancy at birth (yrs)47.350.054.159.762.968.269.770.873.774.8 Increase in longevity since 1900 (yrs) 2.76.812.415.620.922.423.526.427.5

22. Publication of “On The Origin of Species” Upon His Return To England, Darwin Developed His Observations Into The Theory of Evolution Upon His Return To England, Darwin Developed His Observations Into The Theory of Evolution But He Did Not Publish For 25 Years – But He Did Not Publish For 25 Years –Why?

23. Publication of “On The Origin of Species” Darwin Knew That His Theory Would Be Extremely Controversial And Would Be Attacked Darwin Knew That His Theory Would Be Extremely Controversial And Would Be Attacked His Theory Challenged Established Religious & Scientific Beliefs, Particularly About The Creation Of Man His Theory Challenged Established Religious & Scientific Beliefs, Particularly About The Creation Of Man

24. Publication of “On The Origin of Species” He Refused To Publish Until He Received An Essay From Alfred Wallace He Refused To Publish Until He Received An Essay From Alfred WallaceAlfred WallaceAlfred Wallace –Fellow Naturalist –Independently Developed The Same Theory

25. Natural Variation & Artificial Selection Natural Variation Natural Variation –Differences Among Individuals Of A Species Artificial Selection Artificial Selection –Selective Breeding To Enhance Desired Traits Among Stock or Crops

26. Natural Variation & Artificial Selection In Artificial Selection, Nature Provided The Variation Among Different Organisms, And Humans Selected Those Variations That They Found Useful

27. Evolution By Natural Selection how does evolution occur? The Struggle for Existence The Struggle for Existence Survival of the Fittest Survival of the Fittest Descent with Modification Descent with Modification

28. The Struggle for Existence Malthus’ Influence Malthus’ Influence –High Birth Rates & Limited Resources Would Force Life & Death Competition Each Species Struggles For: Each Species Struggles For: –Food –Living Space –Resources

29. Survival of the Fittest Fitness Fitness –Ability of an Individual To Survive & Reproduce Reproduce Adaptation Adaptation –Inherited Characteristic That Increases an Organisms Chance for Survival

30. Survival of the Fittest Adaptations Can Be: Adaptations Can Be: –Physical »Speed, Camouflage, Claws, Quills, etc. –Behavioral »Solitary, Herds, Packs, Activity, etc.

31. Survival of the Fittest Fitness Is Core To The Process Of Evolution Fitness Is Core To The Process Of Evolution Individuals With Low Fitness Individuals With Low Fitness –Die –Produce Few Offspring Survival of the Fittest AKA Natural Selection

32. Survival of the Fittest Over Time, Natural Selection Results In Changes In The Inherited Characteristics Of A Population. These Changes Increase A Species Fitness In Its Environment

33. Descent With Modification Over Long Periods Over Long Periods Natural Selection Can Be Observed As Changes In Natural Selection Can Be Observed As Changes In –Body Structures –Ecological Niches –Habitats

34. Descent With Modification Species Today Look Different From Their Ancestors Species Today Look Different From Their Ancestors Each Living Species Has Each Living Species Has –Descended –With Changes –From Other Species –Over Time

35. Descent With Modification Implies Implies –All Living Organisms Are Related –Single Tree of Life »DNA, Body Structures, Energy Sources Common Descent Common Descent –All Species, Living & Extinct, Were Derived From Common Ancestors

36. Evidence of Evolution Darwin Argued That Living Things Have Been Evolving On Earth For Millions of Years. Evidence For This Process Could Be Found In: –The Fossil Record –The Geographical Distribution of Living Species –Homologous Structures of Living Organisms –Similarities In Early Development

37. Fossil Record Earth is Billions of Years Old Earth is Billions of Years Old Fossils In Different Layers of Rock Showed Evidence Of Gradual Change Over Time Fossils In Different Layers of Rock Showed Evidence Of Gradual Change Over Time

38. Geographic Distribution of Living Species Different Animals On Different Continents But Similar Adaptations To Shared Environments Different Animals On Different Continents But Similar Adaptations To Shared Environments

39. Homologous Body Structures Scientists Noticed Animals With Backbones Had Similar Bone Structure Scientists Noticed Animals With Backbones Had Similar Bone Structure –May Differ In Form or Function »Arms, Wings, Legs, Flippers –Limb Bones Develop In Similar Patterns

40. Homologous Body Structures Homologous Structures Homologous Structures –Structures That Have Different Mature Forms But Develop From The Same Embryonic Tissues –Shows Strong Evidence of A Common Ancestor

41. Homologous Body Structures

42. Not All homologous structures Serve Important Functions Not All homologous structures Serve Important Functions –Vestigial Organs »Appendix In Man »Legs On Skinks (type of lizard)

43. Similarities In Early Development Embryonic Structures Of Different Species Show Significant Similarities Embryonic Structures Of Different Species Show Significant Similarities ChickenTurtle Rat Human

44. REVIEW: Darwin's Theory 1. Individual Organisms In Nature Differ From One Another. Some Of This Variation Is Inherited 2. Organisms In Nature Produce More Offspring Than Can Survive, And Many Of These Offspring Do No Reproduce

45. Darwin's Theory 3. Because More Organisms Are Produced Than Can Survive, Members Of Each Species Must Compete For Limited Resources 4. Because Each Organism Is Unique, Each Has Different Advantages & Disadvantages In The Struggle For Existence

46. Darwin's Theory 5. Individuals Best Suited To Their Environment Survive & Reproduce Successfully – Passing Their Traits To Their Offspring. 6. Species Change Over Time. Over Long Periods, Natural Selection Causes Changes That May Eventually Lead To New Species

47. Darwin's Theory 7. Species Alive Today Have Descended With Modifications From Species That Lived In The Past 8. All Organisms On Earth Are United Into A Single Tree Of Life By Common Descent