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Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
Evolution
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Evolution

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Common Core Support Standards Addressed (8th grade): …

Common Core Support Standards Addressed (8th grade):
8.E.2.1 – Infer the age of Earth and relative age of rocks and fossils from index fossils and ordering of rock layers (relative dating and radioactive dating).
8.E.2.2 - Explain the use of fossils, ice cores, composition of sedimentary rocks, faults, and igneous rock formations found in rock layers as evidence of the history of the Earth and its changing life forms.
8.L.4.1 – Summarize the use of evidence drawn from geology, fossils, and comparative anatomy to form the basis for biological classification systems and the theory of evolution.
8.L.4.2 – Explain the relationship between genetic variation and an organism’s ability to adapt to its environment.

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  • 1. ev·o·lu·tion/ evə looSHən/ˌ ˈ ͞(noun) the process by whichsomething changes overtime
  • 2. The Lithosphere• The lithosphere is the hard outermostshell of our planet on which we live.• In the mantlebelow it ismolten rockcalledmagma.
  • 3. VolcanosEvidence of molten rock below thelithosphere is lava flowing at thesurface from volcanos.
  • 4. Plate TectonicsThe lithospherefloats above themolten rock andit is not one solidsheet but asevidenced byvolcanic andseismic activity itis broken intoplates.
  • 5. Boundaries• The place where 2 plates meet are calledboundaries.• There are 3 types of boundaries:
  • 6. Divergent Boundaries• At divergent boundaries the plates aremoving away from one another.• This is happening at the bottom of theoceans creating a deep ocean trench.• Also referred to as sea-floor spreading.
  • 7. Convergent BoundariesThere are 2 type of convergentboundaries; these are typically areas ofmountain building and uplift.
  • 8. Transform Boundaries• Transform boundaries happen where 2plates are sliding past one another inopposite directions.• The most classic example of this is the SanAndreas Fault line:
  • 9. The Ring of Fire• The boundaries of the Pacific Plate arecollectively known as the Ring of Fire due to thehigh amount of volcanic and seismic activity.• The HawaiianIslands have beenbuilt up from lavaflowing from what iscalled a hot spotwhich is a sort ofweak spot in thelithosphere.
  • 10. Igneous Rock• Cooled and hardened lava is called igneous rock.• Depending on the minerals (type of molecules)contained in the lava and the environment in whichit cooled there is a wide variety of differentformations of igneous rock such as:• Lava that cools rapidly (as in in cold water) doesn’t have time toform crystals and becomes a type of black glass which is calledobsidian.• Lava that contains a lot of gases trapped in it becomes verylightweight rock called pumice.
  • 11. ErosionMountains are built and mountains are brokendown into smaller and smaller pieces throughmany types of weathering. When those pieces aremoved from one place to another it is callederosion. There are 2 general categories:PHYSICALCHEMICAL
  • 12. Physical WeatheringThe main agents of physical (aka mechanical)are:– Water– Wind– Glaciers– Wedging
  • 13. Erosion by Water• As a river flows from the mountains to the sea, theriver forms a variety of features including valleys,waterfalls, flood plains, meanders, and oxbowlakes.• As the river flows down the mountain it picks upsediment, very tiny pieces of chipped off rock.
  • 14. Erosion by Waves• The energy in waves comes from wind that blowsacross the water’s surface. • As the wave approaches the shore it makescontact with the bottom shaping and sculpting itwith its full force, tumbling (smoothing) rocks andshells caught in its grip.
  • 15. Erosion by Glaciers• Glaciers are giant rivers of ice that move ever soslowly across the landscape grinding and polishingand sometimes even picking up rocks andsediment along the way.• When they melt/recede they can leave gouges inthe earth and even giant boulders behind.
  • 16. Erosion by Wind• Wind is the weakest agent of erosion and reallyonly effects places where there are no plants tohold down the soil (dunes, deserts).• Wind moves surface materials around in a processcalled deflation and it can polish rocks in aprocess called abrasion (think sand blasting).
  • 17. Wedging• As cracks in rocks form, rain can seep down in thecracks and then if the rainwater freezes, itexpands, wedging the crack apart wider and wider.This is called frost wedging.• Plant roots can also act as a wedge to pry apartrocks; we call this root wedging.
  • 18. Sediment Deposition• The small pieces of material that come from rocksor plant & animal remains are called sediment.• After sediment is picked up by various agents oferosion (wind, water, glaciers, waves) it must comeback down…and this is part of the process of iscalled deposition.
  • 19. Sedimentary Rock• When layers of sediment accumulate/build up andthey stick together over time they becomesedimentary rocks.• Ex: Mudstone, Sandstone, Shale, Conglomerate• This is the type of rock in which one would findfossils.
  • 20. Metamorphic Rock• When igneous and sedimentary rock are exposedto heat and/or pressure chemical changes happenin the rock that transform them into different rocks.• This type of rock is especially hard and durable.• Examples:– Marble (parent rock is limestone which is sedimentary)• Used in statuary and as a building material– gneiss (parent rock is granite which is igneous)– slate (parent rock is shale which is sedimentary)• Used as old school chalkboards and in pool tables
  • 21. What is a Rock?• Rocks are non-living substances made up of minerals.• Minerals are naturally occurring, homogeneous inorganicsolid substances having a definite chemical compositionand characteristic crystalline structure, color, andhardness.
  • 22. The Rock Cycle• All rock begins its journey around the Earth as magmaunder the surface. It comes to the surface as lava andcools to form igneous rock.• Igneous rocks are worn down over time through erosionand deposited in layers before being cemented intosedimentary rock.• With heat and pressure igneous and sedimentary rockscan change their chemical composition becomingaltogether different rocks called metamorphic rocks.• With additional heat and pressure the rocks melt back intomagma and the process begins all over again.
  • 23. Fossils• The preserved remains or traces of an organism that livedin the past are called fossils.• Scientists that study fossils are called paleontologists.• The fossil record provides invaluable information about thehistory of life and past environments on Earth, includingthe climate.• In many cases the fossil remains are all remains of someextinct species.• It has been estimated that over 99.9% of all species thatever lived are now extinct (no longer existing).
  • 24. Types of Fossils• Fossils are ONLY found in sedimentary rock and there areseveral different types of fossils such as: Petrification Casts Molds Carbon films Trace fossils Preserved remains
  • 25. Petrification• Petrification means “turned into stone.”• This is a process in which all the parts of the organism arereplaced with minerals.
  • 26. Casts & Molds• A mold is a hollow area in the shape of an organism.• When that mold fills in with sediment and that sedimenthardens into the shape of the organism, that “copy” iscalled a cast.
  • 27. Trace Fossils• Trace fossils provide evidence of the activities of ancientorganisms such as: Footprints which tell paleontologists how they moved,if they lived alone, etc. Poop – aka coprolite (fancy scientific term for fossilizedpoop) Specialized habitats such as nests, burrows or dens.
  • 28. Carbon Films• Carbon films are thin sheets of carbon only that are leftbehind on rock when the other components of theorganism decay away.• Paleontologists that specialize in ancient plants and fishget a lot of information from these as they preservedelicate small fishbones, flowers and leaves very well.
  • 29. Preserved Remains• Sometimes entire organisms can be preservedin special conditions where there is an absenceof exposure to oxygen such as: Tar pits – thick oil Ice Amber – tree sap
  • 30. Index FossilsIndex FossilsIndex fossils are particularly helpful in determiningthe age of a rock layer in the field because they:•Are distributed widespread geographically•Existed for a short range of geologic time•Examples:< Trilobites lived from about 500 million years ago to 250million years ago< Ammonites indicate an age range of about 440 millionyears ago to 360 million years ago
  • 31. Dating TechniquesGeologists and archaeologistsemploy two main datingtechniques to determine theage of rocks (or artifacts): Relative Dating Absolute Dating
  • 32. Relative Dating• Relative dating can determinethe sequential order in which a series ofevents occurred, not when (the actualabsolute date) they occur.• Relative dating is done with 3 basic lawsof geology in mind:The Law of SuperpositionThe Law of Original HorizontalityThe Law of Crosscutting Relationships
  • 33. Law of SuperpositionThe Law of Superpositionstates that in horizontalsedimentary rocks, thebottom layer is oldest &each layer above it isincreasingly younger…
  • 34. The Law of OriginalHorizontalityThe Law of Original Horizontality states that in general(though there are a very few exceptions) sediment isdeposited horizontally.
  • 35. Law of CrosscuttingRelationshipsThe Law of Crosscutting Relationships states that anyrock that cuts across sediment layers is younger than theyoungest layer it cuts through.
  • 36. UnconformityAn unconformity is a place in the rock record where anentire layer of rock has been eroded away creating a gap inthe timeline.
  • 37. Absolute Dating• Absolute dating uses natural radioactivedecay within the rock to establish anactual date.• Also called radiometric dating.
  • 38. The AtomThe Atom• Nucleus– Protons – positive charge– Neutrons – neutral/NO charge• Orbiting the nucleus– Electrons – negative charge
  • 39. Atomic StructureAtomic Structure• Atomic numberAn element’s identifying number!Number of protons in the atom’snucleus• Mass numberNumber of protons plus (addedto) the number of neutrons in anatom’s nucleusIsotope• Variant of the same parent atom• Different number of neutronsand therefore a different massnumber
  • 40. RadioactivityRadioactivityRadioactivity is the spontaneousbreaking apart (decay) of atomic nuclei• Parent – an unstable isotope• Daughter products – isotopes formed from thedecay of a parent
  • 41. Radioactive DecayRadioactive DecayTypes of radioactivedecay• Alpha emission• Beta emission• Electron capture
  • 42. Radiometric DatingRadiometric Dating• Half-life – the time for one-half of theradioactive nuclei to decay• Requires a closed system• Cross-checks are used for accuracy• Complex procedure• Yields numerical dates
  • 43. Decay CurveDecay Curve
  • 44. Carbon-14Carbon-14• Half-life of only 5,730 years• Used to date very recent events• Carbon-14 produced in upper atmosphere• Incorporated into carbon dioxide• Absorbed by living matter• Useful tool for anthropologists,archaeologists, historians, and geologistswho study very recent Earth history
  • 45. Geologic time scaleGeologic time scale4 billion years is a REALLY long difficultto fathom length of time.Geologists have divided that history intomanageable units.The timeline was originally createdusing relative dates but has since beenedited using radiometric techniques.
  • 46. EonEon• Eons are the largest subdivision of geologic time• Four eons from oldest to most recent –– Phanerozoic– Proterozoic– Archean– Hadean
  • 47. ErasEras• Eons are subdivided into Eras• Eras of the Phanerozoic eon• Cenozoic (“recent life”)• Mesozoic (“middle life”)• Paleozoic (“ancient life”)
  • 48. PeriodsPeriods• Eras aresubdivided intoperiods.• Fossils beforethe cambrianare rare so allof geologichistory beforethe cambrian isrefered tosimply as theprecambrian.
  • 49. EpochsEpochs• Periods are subdivided intoepochs.• We are currently living inthe holocene.
  • 50. Problems with DatingProblems with Dating• Not all rocks are datable. For instancesedimentary ages are rarely reliable becausethey are collections of sediment from rocks ofdiffering ages.• Materials are often used to bracket events andarrive at ages.
  • 51. The PrecambrianThe PrecambrianThe Precambrian is from Earth’s formation 4.6billion years ago to about 543 million years ago and ischaracterized by:– Volcanic eruptions, meteorites, intense radiation from the sun– Early atmosphere had no oxygen– Prokaryotic organisms (no nucleus)– Cyanobacteria appeared producing their own food from thesun’s energy from photosynthesis and they created the oxygenatmosphere.– The Ozone layer forms in the upper atmosphere and absorbsradiation from the sun.
  • 52. The PaleozoicThe PaleozoicThe Paleozoic spans from 541 to 252.2 millionyears ago and is characterized by:⁻Rocks rich in fossils of sea creatures such as sponges, corals,clams, squids, and trilobites⁻Fishes appear, sharks are more abundant⁻Forests of giant ferns covered earth
  • 53. Gondwanaland
  • 54. The MesozoicThe MesozoicThe Mesozoic spans from 252 to 66 million yearsago and is characterized by:– Dinosaurs and other reptiles, referred to as The Ageof Reptiles– First birds appeared; flowering plants appeared– The “birth of the Himalayas.”– Ending in a mass extinction event in which ~75% of non-avian dinosaurs disappear.– The extinction event is believed to have been caused by ameteorite impact due to a rock layer from that time (calledthe K-Pg Boundary) that contains extremely high levels ofiridium which is rare on Earth but common in meteors.
  • 55. The CenozoicThe CenozoicThe Cenozoic spans from 66 million years ago tothe present and is sometimes referred to as the “Ageof Mammals”– Mammals included mastodons, wholly mammoth, saber-toothed cats, camels, and giant ground sloths– Included some periods of heavy glaciation known as ice ages– Includes the emergence of man
  • 56. Natural SelectionNatural SelectionNatural selection is the gradual, non-random process by which biological traitsbecome either more or less common in apopulation through reproduction.
  • 57. VariationVariationThe heritable differences that exist in every populationthat are the basis for natural selection.
  • 58. OverproductionOverproductionOrganisms produce more offspring than can survivewhich increases the survival of the species butcreates competition for resources.
  • 59. AdaptationAdaptationA variation that allows certain offspring a betterchance to survive and most importantly to reproduce.
  • 60. Descent with ModificationDescent with ModificationOver time, natural selection will result in species withadaptations that are well suited for survival andreproduction in a given environment.
  • 61. Evidence for EvolutionEvidence for Evolution• Adaptations–Structural–Physiological• Fossils• Anatomy–Homologous structures–Analogous structures• Biochemistry
  • 62. MimicryMimicryExamples:•Coral snakes (venomous) and king snakes (non-venomous) Theharmless king snake mimics the poisonous coral snake, causingwould-be-predators to avoid them.•Monarchs (toxic to predators) and viceroys (non-toxic). Theviceroys mimics the coloration and pattern of the unpalatablemonarch, also avoiding would-be-predators.
  • 63. CamouflageCamouflageCamouflage is the use of any combination of coloration orillumination for concealment, either by making them hard to see, orby disguising them as something else.
  • 64. CamouflageCamouflageCamouflage is the use of any combination of coloration orillumination for concealment, either by making them hard to see, orby disguising them as something else.
  • 65. Physiological AdaptationsPhysiological AdaptationsExample:
  • 66. FossilsFossilsFossils in olderlayers are moreprimitive thanthose in upperlayers.
  • 67. ““Missing Links”Missing Links”Example:Archaeopteryx links reptiles and birds.
  • 68. Homologous StructuresHomologous StructuresSimilarities in thebone structure of theforelimbs of mammalsdemonstrate evidencefor evolution:comparative anatomyand commonancestry.
  • 69. Analogous StructuresAnalogous StructuresShow similarities infunction, but are notevidence of acommon ancestor--anexample ofconvergent evolution.
  • 70. Vestigial StructuresVestigial StructuresStructures that have lostmost or all of its ancestralfunction in a given speciesbut they do indicate commonancestry.Examples:•Whale & snakehip bones•Human appendix•Human tail bone(coccyx)
  • 71. EmbryologyEmbryology• The study of the development of an embryo fromthe fertilization of the ovum to the fetus stage.• The embryos of fish, reptiles and mammals all have a tailand pharyngeal pouches. In fish, these pouches develop intothe supports for the gills, while in the mammals and reptiles(birds too), they develop into parts of ears, jaws, and throat.• These shared features in young embryos suggest evolutionfrom a distant, common ancestor.
  • 72. BiochemistryBiochemistry• 95% of all life on Earth is made of just 6elements: CHNOPS.• Cells of all living organisms contain DNAwith the same 4 base nucleotides.• All living organisms produce ATP forenergy.• Similarities in DNA sequences can be used toshow common ancestry; the more similarities,the more recently evolved the species are fromone another.

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