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Similar to Evolution natural selection_and_speciation most current file
Evolution natural selection_and_speciation most current file
- 2. “Evolve” Means toChange Over Time The notion that life on Earth has changed over time is quite old To be considered science, this notion requires a great deal of evidence
- 3. The Development ofEvolutionary Theory Naturalists have always wondered at the diversity of living things……… Great varieties in shape, size, and ecological role Estimated 3 million to 20 million different living species Much of the natural world’s biodiversity has vanished through extinction 99% of all species that ever lived are now extinct Permian-Triassic Mass Extinction What Killed the Dinosaurs?
- 7. Development of EvolutionaryTheory What could cause such great diversity, and why have so many species died out? Charles Darwin offered an explanation based on careful observations Who was Charles Darwin?
- 11. Development of EvolutionaryTheory Darwin Concluded: Physical traits and behaviors enable organisms to survive and reproduce (called Fitness ) Fitness results from adaptations Structural (body structures) Behavioral (protection, predation, mating, etc.) Functional (chemicals produced by the organism that perform special functions)
- 13. Development of EvolutionaryTheory Darwin reasoned that adaptations result from natural selection and result in evolution Evolution is the process by which living things change and diversify over time
- 14. Development of EvolutionaryTheory These ideas were widely challenged until a tremendous amount of evidence was gathered to support evolution! Now…The Theory of Evolution is the Cornerstone of Biology Explore the Evolution Revolution
- 15. Natural Selection and Speciation
- 16. Charles Darwin StudiedMedicine and Theology Excelled in Geology and Biology In 1831 Darwin joined the H.M.S. Beagle on a trip around the world to make maps He was the ship’s naturalist Darwin’s Diary
- 17. Darwin Pieces Togetherthe Puzzle Darwin traveled South America & Galapagos Islands Collecting fossils and other specimens Making detailed observations of animal behavior Making detailed drawings of the organisms he encountered
- 18. The Voyage ofthe Beagle: Ports of Call Noted that populations of organisms were slightly different from place to place Each group was modified to their specific environment
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- 24. The Origin ofSpecies Interactive Exploration
- 25. Darwin Pieces Togetherthe Puzzle Author of “Principles of Charles Lyell Geology” This book helped Darwin realize that the earth is old and changes slowly over time.
- 26. Darwin Pieces Togetherthe Puzzle Thomas Malthus Malthus wrote “Essay on the Principles of Population” Populations will always grow larger than the food supply, creating hunger, disease and struggle/competition. Some people live, others die. 18th Century Economist
- 27. Darwin Pieces Togetherthe Puzzle Darwin coined the term Artificial Selection - the process of modification of a species through human actions which encourage the breeding of certain traits over others. http://www.esp.org/books/darwin/variation/facsimile/title3.html
- 28. Darwin Pieces Togetherthe Puzzle What Darwin Learned from Artificial Selection When chosen organisms are mated, desired characteristics are formed (Darwin didn’t know about DNA) Individuals in the wild who possess characteristics that make it more likely for them to reproduce will pass along these characteristics to their offspring. “Desirable" characteristics, in the wild, would be those which enhance survivability, NOT those which specifically satisfy human needs. Nature does the selecting.
- 29. Darwin Pieces Togetherthe Puzzle Lamarck’s View of Evolution Stated that acquired characteristics can be passed on to offspring.
- 30. Darwin Pieces Togetherthe Puzzle Darwin’s View of Evolution Those giraffes with longer necks got more food and were better able to survive to reproduce, passing on the long-neck genes to their offspring. Over time, giraffes evolved longer necks.
- 32. 4 Key Ideasof Natural Selection “Of course, long before you mature, most of you will be eaten.”
- 33. Natural Selection Evolution ThroughNatural Selection Variation (genetic) is present in the population and this variation is inherited (genetically passed to offspring). (Praying Mantis Camouflage) Living things Overproduce Competition for Limited Resources Survival of the “Fittest” Reluctantly published On the Origin of Species in 1859 Video
- 34. Natural Selection 4 MainPoints of Natural Selection Variation (genetic) is present in the population and this variation is inherited (genetically passed to offspring). Living things Overproduce Competition for Limited Resources Survival of the “Fittest” Video
- 36. The Fittest Survive FitnessDefined Organisms who better survive to produce larger numbers of offspring are considered more fit than others who do not.
- 37. Darwin Today… Natural Selectionin action… causes a frequency of certain alleles in a population to increase or decrease over time!
- 40. Click the LinkBelow to Access the Cartoon http://evolution.berkeley.edu/evolibrary/artic Read the cartoon carefully and answer the discussion questions on a separate sheet of paper.
- 41. Speciation Results inBiodiversity
- 42. Speciation Natural Selection modifies populations. Some evolutionary changes are so great that some organisms can no longer interbreed with the original population A new species results Species An interbreeding population of organisms that can produce healthy, fertile offspring
- 43. Reproductive Barriers andSpeciation Prezygotic: gametes never meet and fuse Geographic isolation (allopatric speciation) Ecological isolation Behavioral isolation (lacewing songs) Mechanical isolation Seasonal isolation Postzygotic: genetic differences manifest Hybrid inviability Hybrid sterility (tigons and ligers)
- 44. Geographic Isolation 2 populations separatedby geographic barriers (rivers, mountains, bodies of water) Abert Squirrel vs. Kaibab Squirrel
- 46. Temporal Isolation (Seasonal) Speciesreproduce at different times
- 47. Behavioral Isolation Differences in courtshiprituals or other types of behavior Songs of birds
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- 49. Mechanical Isolation Mating/Pollination isoften impossible between different animal/plant species because of the incompatible shape and size of the reproductive structures. Size Does Matter! Example – Black and White Sage Plants
- 51. Black sage andwhite sage plants invite different pollinators White sage flowers have large landing platforms for large pollinators causing the large pollinators to brush against the stamens, but the small ones usually don’t. Black sage flowers have small landing platform for small pollinators. Therefore, the small pollinators cannot spread pollen to the white sage flowers therefore cross pollination is no longer possible.
- 52. Ecological Isolation Two populations live in different habitats and mating occurs in those habitats, thus their own gene pool. Land Iguana Marine Iguana
- 53. After Mating GeneticDifferences Occur Hybrid sterility (tigons and ligers) (Horse and a donkey = mule – sterile)
- 54. Patterns in Evolution Adaptive Radiation (Divergence) Development of numerous new species from a common ancestor in diverse environments Darwin’s Finches (Origin of Species Activity)
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- 56. Pages to turnin: 63 107-109 #1-31 131 137 139 These assignments will calculate towards the 4th quarter grade. Once these are turned in you may work on the EC assignment
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- 58. Evolution Produces Diversity Allliving things are classified by characteristics into 6 kingdoms of life
- 59. Archaebacteria Autotrophic and heterotrophicspecies Unicellular Prokaryotic Cell wall w/o Peptidoglycan Some mobile Ancient bacteria Live in extreme environments (extremeophiles) Methanogens, Halophiles, Thermoacidophiles
- 60. Eubacteria Autotrophic and heterotrophic Unicellular Prokaryotic Cell wall with Peptidoglycan Some mobile True bacteria E. coli, Streptococcus
- 61. Protist Autotrophic and heterotrophic Mostlyunicellular Eukaryotic Cell wall on most Some mobile “Odds and ends” Kingdom Amoeba, Paramecium
- 62. Fungi Heterotrophic Mostly multicellular Eukaryotic Cell wall made of chitin Immobile Mostly live on decaying organic matter Fungi, yeast, mold
- 63. Plant Autotrophic Multicellular Eukaryotic Cell wall madeof cellulose Immobile Produce oxygen through photosynthesis Trees, shrubs, grasses, flowers
- 64. Animal Heterotrophic Multicellular Eukaryotic No Cell Wall Mobile Mammals, insects, birds, reptiles, sponges, worms
- 65. Taxonomy Classification and namingof organisms 7 Taxonomic Groupings from most inclusive to most specific: • Kingdom “Kings play chess on fine green silk” • Phylum • Class • Order • Family • Genus • Species
- 66. Linnean Taxonomy Carolus Linnaeus(1707-1778) Binomial nomenclature (2 name naming) Genus and species to make the scientific name Provides a common name that can be used by all biologists regardless of their native language.
- 67. Linnean Taxonomy Example: human vs. chimpanzee • Kingdom animalia animalia • Phylum chordata chordata • Class mammalia mammalia • Order primata primata • Family hominidae hominidae • Genus homo pan • Species sapiens troglodytes • Homo sapiens and Pan troglodytes • Classification activity
- 69. Scientists from manydisciplines including biology, chemistry, physics, geology, and paleontology have contributed to the case for evolution! The Origin of Life Geology The Fossil Record Comparative Embryology Comparative Biochemistry Comparative Anatomy Isn’t Evolution Just a Theory?
- 71. The Origin ofLife Origin of the Universe Big Bang
- 72. Early Earth Evolution Starts Up: Chemical Evolution Heterotroph Hypothesis: Molecules of life arose from inorganic building blocks
- 73. The Miller-Urey Experiment Studied Molecules Present at Time of Early Earth Methane, Ammonia, Carbon Dioxide, Water Vapor Mixed Molecules in Reaction Chamber Sparked with Electricity to Simulate Lightning Exposed Mixture to UV Radiation to Simulate Cosmic Rays Produced Basic Amino Acids and Organic Molecules
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- 76. Biological Evolution RNAas a information molecule and catalyst Endosymbiotic Theory Mitochondria and chloroplasts were originally free living prokaryotic cells Both have own DNA and ribosomes Joined together to cooperate
- 77. Geology The Study ofthe Earth and Rocks Early Ideas About Earth: People believed Earth was only a few thousand years old People believed that rocks and geological features were shaped by catastrophic events and rarely changed
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- 79. Geology In the 18thand 19th Century Scientists Studied Geology in Great Detail Old Earth, Ancient Life: Georges-Louis Leclerc, Comte de Buffon (1749)
- 80. Hutton (1785) andHadrian’s Wall
- 81. Charles Lyell: ThePrinciples of Geology Earth is Changed by Weather and Natural Processes like Volcanoes and Erosion Takes a Very Long Time! Gradualism and Uniformitarrianism
- 84. Continental Drift •Over millions of years 1 original continent Pangea drifted apart to make our modern continents • Continental drift is gradual “gradualism”
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- 89. Geology These ideas refutethe idea that the Earth is only a few thousand years old Provides long time necessary for evolution Backed up by radiometric dating The Earth is approximately 4.6 Billion Years Old 4,600,000,000 years is a long time!
- 91. Direct Evidence ofEvolution
- 92. The Fossil Record Fossils are the preserved remains of ancient organisms Provide information about past organisms Shows that many diverse organisms lived at different times in Earth’s History
- 93. Preserved remains ortraces of ancient organisms Examples:
- 94. The Fossil Record Provide a record of past species Important source of information for determining ancestry and patterns of evolution Fossil Archaeopteryx
- 95. What does thefossil record tell us? •What past life looked like •What past habitats were like and changes that have occurred •That diverse organisms lived on earth at different times •New species evolved •Some species became extinct •Earliest life forms were aquatic •Earliest life forms were simple in structure http://www.pbs.org/wgbh/evolution/library/04/3/quicktime/l_043_01.html
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- 97. The Fossil Record Taphonomy: The Formation of Fossils Fossils form in sedimentary rock Dead organisms covered by sand and silt Sediments are passed into bone by pressure from above (fossils form in sedimentary rock) Video
- 99. Determining the Ageof Fossils Relative Dating: Technique used by scientists to determine the age of fossils relative to fossils in other layers of rock Different layers represent different geologic periods Older fossils found in lower layers, newer fossils found in upper layers Cannot determine the actual age of the fossil!
- 102. Determining the Ageof Fossils Radioactive Dating: Process by which traces of radioactive elements are analyzed to calculate the actual age of a fossil Many radioactive elements can be used as geologic clocks. Each radioactive element decays at its own nearly constant rate. Once this rate is known, geologists can estimate the length of time over which decay has been occurring by measuring the amount of radioactive parent element and the amount of stable daughter elements Video
- 103. Radioactive/Radiometric Dating How itWorks: - radioactive elements (uranium, Carbon14) break down/decay a specific rates = half life - these rates are nearly constant - the amount of radioactive decay that has taken place in a rock/fossil determines its age
- 104. Scientist Measure theAge of the Earth Radiometric Dating: way of estimating the age of the Earth! http://www.pbs.org/wgbh/evolution/library/03/3/quicktime/l_033_01.html
- 105. 5,700 year is C14 half-life Carbon-14 Dating - Determines the age of fossils of a biological origin up to approx. 50,000 years old. - used in dating things such as bone, cloth, wood, plant fibers, etc.
- 107. Half-life of carbon-14is 5730 years
- 108. Half-life of carbon-14is 5730 years 22,920 11,460 28,650 17,190
- 109. Radiometric Dating Radioactive Stable Half life Parent Daughter 1.25 billion Potassium 40 Argon 40 yrs Strontium 48.8 billion Rubidium 87 87 yrs 14 billion Thorium 232 Lead 208 years 704 million Uranium 235 Lead 207 years 4.47 billion Uranium 238 Lead 206 years Carbon 14 Nitrogen 14 5730 years
- 110. The Geologic TimeScale Based on fossil and geologic evidence A record of the Earth’s past Divided into Era, Period, and Epoch Shows that life on Earth followed geologic change on Earth Deep Time Activity Interactive Time Scale
- 112. Comparative Embryology Embryosare organisms at early stages of development
- 113. Comparative Embryology All vertebrateembryos, including humans, share features Eye spot • (Evolution of the Human Eye) Gill pouches Notochord Shows similar genetic ancestry Video
- 114. Comparative Biochemistry All lifeis based on organic chemistry Carbon based compounds All life uses same molecule as blueprint DNA Similar chemical processes Bacteria, algae, and plants all do photosynthesis Similar organisms have similar genetic code Humans and chimpanzees share nearly identical genes (98.4% identical gene sequences) Video
- 115. Anatomy and ComparativeAnatomy Vestigial Organs Organs inherited but not used by modern organisms Present but greatly reduced in modern organisms Hip bone in python Appendix in human Tail bone (cocyx) in human
- 116. Anatomy: Homologous Structures Similar parts of different organisms, often quite dissimilar in purpose, that developed from the same ancestral body parts (Video) Divergent evolution
- 117. Anatomy: Analogous Structures Similar in purpose, but not inherited from a recent common ancestor Environment selected for trait Wings of birds and insects Convergent evolution
- 118. Summary Thereis overwhelming evidence to support the Theory of Evolution Evidence comes from disciplines as varied as biology, geology, chemistry, physics, astronomy, and paleontology Evolution has produced the great beauty and diversity of life on Earth over the last 4 billion years
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- 120. Explore Human Evolution Viewthe Becoming Human broadband documentary As you view each segment, visit the related exhibits to further explore this topic Go to the Learning Center and select the “Calculating Cousins” activity Go to the Learning Center and select the “Chromosome Connection” activity Go to the Learning Center and select the “Building Bodies” activity
- 121. The Order Primate Characteristics of Primates Strong hands and opposable thumbs Free-moving shoulder joint Forward facing eyes and stereoscopic vision Intelligence/larger brain Social complexity
- 122. What Characteristics doHumans Have? All of those of primates, plus Upright posture and bipedal Use of tools and technology Advanced intelligence Complex communication and speech
- 123. The Steps toHuman Evolution Terrestrialization Bipedal (Walking on all two’s) Increased Brain Size Civilization Take a look at the Human family tree
- 124. The Hominid Family Eachyear new fossils are found to add to the Hominid family tree Most fossils of early humans are found in Africa and lower Asia Most well understood members include genus Australopithecus (extinct) and genus Homo Solve the Riddle of the Bones
- 125. Genus Australopithecus First human ancestor to live on the ground and walk on two legs As evidenced by the Laetoli footprints Ape-like jaw Small brain Short stature Found only in South and East Africa
- 126. The Australopithecines A. anamesis 4 MYA A. afarensis 3.2 MYA (Finding “Lucy”) A. africanus 2.5 MYA A. robustus 2 MYA A. boisei 2 MYA
- 127. Genus Homo More modern hominids that exhibited major evolutionary steps Increased brain size Use of tools Use of fire Use of shelter Religion Language and civilization
- 128. Homo habilis “TheTool Man” Approx. 2.5 MYA Brain ½ size of modern human First to make and use stone tools and weapons
- 129. Homo erectus “TheUpright Man” Direct ancestor of modern humans Widespread in Africa and Asia by 1 MYA Evidence of use of shelter and fire
- 130. Homo sapiens “TheWise Man” Most likely evolved from H. erectus as early as 400,000 years ago Greatly increased brain size Consisted of 2 groups Neanderthal Cro-Magnon/modern H. sapiens
- 131. Neanderthals Foundin Neander Valley in Germany Fossils found throughout Europe, Middle East, and Asia from 150,000-30,000 years ago Large bodies and brains Evidenced painting, religion, complex social structure “Cave man”
- 132. Cro Magnons andFully Modern Humans First early modern H. sapiens appear about 130,000 years ago Thinner bones, smaller jaws, higher skull with little or no brow ridge, and larger brains Cave art shows complex religion and culture Lived alongside Neanderthal for several thousand years, but eventually out-competed them