Journal #4 – Geologic Time 1. What types of information is included on the geologic time scale? 2. What is the difference between an Era and an Epoch?

Geologic Time Scale

Journal #4 Geologic TimeWhat types of information is included on the geologic time scale?What is the difference between an Era and an Epoch?According to the geologic time scale, how has life on Earth changed since the beginning of time?Geologic TimeObjective: Understanding the events of Earths past and how they are organized into a chart.Geologic TimeOrganic EvolutionThe change in life-forms through timeSpeciesA group of organisms that normally reproduce only with themselves

Species2 Different Species BreedOffspring unable to reproduceAdaptationAdaptationThe ability to change to surviveEx. Light colored peppered moths camouflaged on light tree bark; pollution causes them to change to darker colors to surviveEx. Galapagos finches and their beaks

Natural SelectionNatural SelectionOrganisms with traits that are suited to a certain environment have a better chance of surviving and reproducing1836 by Charles DarwinEvolutionMain Causes of EvolutionChanges to the environmentCaused by plate tectonicsCompetition with others for resourcesEndangered vs. ExtinctEndangeredWhen only a small number of members are livingExtinctWhen none of its members are livingExtinctionHuman Contribution to ExtinctionDestruction of habitatsCompetition for same food supplyOverhuntingGeologic TimeGeologic Time ScaleA record of Earths history that shows events of life, earth processes, time units and agesDivided into smaller units based onTypes of life-forms living at that timeGeologic events occurring at that timeGeologic TimeErasPeriodsEpochsLargestBased on life-forms and fossil evidenceDivide ErasBased on life-forms and geologic eventsSmallestDivide PeriodsGeologic TimePrecambrianLongest geologic time unit in Earths historyBegan: 4600 million years ago (4.6 billion years)Ended: 540 million years agoPrecambrianPrecambrian FossilsLimitedRocks deeply buried or erodedRocks have been changed by heat and pressureEarly organisms were soft-bodiedEarly organisms were small and single-celledCyanobacteriaCyanobacteriaBacteria and algae combine and photosynthesize to form stromatolitesAppeared: 3.5 billion years agoTake in CO2, Release O2CyanobacteriaCyanobacteriaImportance: changed Earths atmosphere by adding free oxygen to the airFormed the ozone layer protecting organisms from UV lightSingle-celled organisms evolved into complex organismsInvertebrateInvertebrateAnimal without a backboneAppeared: end of the Precambrian

Ex. Jellyfish, sponges, wormsPaleozoic EraPaleozoic EraAncient LifeBeginning marked by the development of hard partsBegan: 540 million years agoEnded: 245 million years agoPaleozoic EraPaleozoic EraAbundant Life: ocean dwelling marine organismsCaused by warm, shallow seas covering most of earthAppeared: Cambrian Period

Ex. Trilobites, brachiopods, cephalopods, crinoidsPaleozoic Era AnimalsVertebrateAnimals with a backboneAppeared: Ordovician Period

Ex. Jawless fish, bony fishes, reptiles, mammalsPaleozoic Era AnimalsAmphibianVertebrates that live on land by must return to water to reproduce (lay eggs)Appeared: Devonian Period

Ex. Frogs, salamandersPaleozoic Era AnimalsReptilesVertebrates that live entirely on land; eggs have leathery or mineralized coveringAppeared: Late Carboniferous (Pennsylvanian Period)

Ex. Tortoises, snakes, lizards, crocodilesPaleozoic Era PlantsFerns, Palms, Ginkgos, PinesAppeared: Devonian PeriodPaleozoic Era PlantsGymnospermsnaked seed plant; no fruit covering their seedsAppeared: Carboniferous Period

Ex. Eastern White PinePaleozoic EraAppalachian MountainsFormed at the end of the Paleozoic

What marked the end of the Paleozoic?Largest mass extinction in Earths historyFormation of PangaeaMesozoic EraMesozoic EraMiddle LifeAge of the DinosaursBegan: 245 million years agoEnded: 66 million years agoMesozoic EraPangaeaLaurasiaGondwanalandAll ContinentsNorth America, Europe, Asia, GreenlandSouth America, Africa, Antarctica, India, AustraliaMesozoic Era AnimalsSmall DinosaursAppeared: Triassic PeriodEvidence of being Warm-BloodedTracks (trace fossils) indicate fast motionTraveled in herds and nurtured youngBone structure resembles other warm-blooded animalsMesozoic Era AnimalsMammalsAppeared: Triassic PeriodTraits Allowing SurvivalHair or FurWarm BloodedProduce Milk to Feed YoungMesozoic Era AnimalsBirdsAppeared: Jurassic PeriodEx. Archaeopteryx had wings and feathers like a bird, teeth, claws and tail like a dinosaurMesozoic Era PlantsAngiospermsFlowering plantsProduce seeds with a hard outer covering and/or fruitAppeared: Early Cretaceous Period

Ex. Fruits, vegetables, flowers, flowering treesMesozoic EraWhat marked the end of the Mesozoic Era?Break up of PangaeaSeas drained from landsExtensive volcanismExtinction of the dinosaursCenozoic EraCenozoic EraRecent LifeAge of the MammalsBegin: 66 million years agoCurrent Time

Cenozoic EraAlps in EuropeForm from the collision between African and Eurasian PlatesCenozoic EraThe Himalaya MountainsFormed from the collision between the Indian and Eurasian Plates Cenozoic Era AnimalsPlacental MammalsNourish their young internally from a placentaOffspring born live and independentFirst Appeared: Cretaceous Period

Ex. Rodents, bats, dogs, cats, cows, humansCenozoic Era AnimalsMarsupialsOffspring are born immatureMust complete development in a pouchFirst Appeared: Cretaceous Period

Ex. Kangaroo, koala, wombat, opossum

Australia has the greats population of marsupialsCenozoic Era AnimalsMonotremesEgg-laying mammals

Ex. PlatypusHomo SapiensHomo SapiensHomo Sapiens NeanderthalensisHomo Sapiens Sapiens500,000 years ago250,000 years ago100,000 years agoHumansHumansDominant life form for the past 10,000 yearsStarted agriculture, domestication of animals, cities, writing