2Chapter 14 The History of Life Section 1: Fossil Evidence of ChangeSection 2: The Origin of Life
3Earth formed about 4.6 billion years ago as a molten planet. Chapter 14The History of Life14.1 Fossil Evidence of ChangeLand EnvironmentsEarth formed about 4.6 billion years ago as a molten planet.Gravity pulled the densest elements to the center of the planet during the first 500 million years.After about 4 billion years, a solid crust formed on the surface, but molten outer core remains.Volcanoes erupted, giving off gases and forming the early atmosphere.
514.1 Fossil Evidence of Change Chapter 14The History of Life14.1 Fossil Evidence of ChangeAtmosphereThe gases that likely made up the atmosphere are those that were expelled by volcanoes.Water vapor (H2O)Carbon dioxide (CO2)Sulfur dioxide (SO2)Carbon monoxide (CO)Hydrogen sulfide (H2S)Hydrogen cyanide (HCN)Nitrogen (N2)Hydrogen (H2)
6A fossil is any preserved evidence of an organism. Chapter 14The History of Life14.1 Fossil Evidence of ChangeClues in RocksA fossil is any preserved evidence of an organism.Most organisms decompose before they have a chance to become fossilized.Are found in the earth’s crust – the very uppermost part of the earth that is exposed to the surface, or lying immediately below the oceans.
714.1 Fossil Evidence of Change Chapter 14The History of Life14.1 Fossil Evidence of Change
9Nearly all fossils are formed in sedimentary rock. Chapter 14The History of Life14.1 Fossil Evidence of ChangeFossil FormationThe three most common material that fossils form in are sedimentary rock, amber, and ice.Nearly all fossils are formed in sedimentary rock.The sediments build up until they cover the organism’s remains.Minerals replace the organic matter or fill the empty pore spaces of the organism.
13Does not give exact ages Chapter 14The History of Life14.1 Fossil Evidence of ChangeDating fossilsRelative dating is a method used to determine the age of rocks by comparing them with those in other layers.Does not give exact ages
14Law of Superposition:Youngest on Top An undeformed sedimentary rock layer is older than the layers above it and younger than the layers below itDCBA
15Radioactive isotopes that can be Chapter 14The History of Life14.1 Fossil Evidence of ChangeRadiometric DatingUses the decay of radioactive isotopes to accurately measure the age of a rockRadioactive isotopes that can beused for radiometric dating are found only inigneous or metamorphic rocks.
16The Geologic Time Scale Chapter 14The History of Life14.1 Fossil Evidence of ChangeThe Geologic Time ScaleThe geological time scale is a model that expresses the major geological and biological events in Earth’s history.The geologic time scale is divided into the Precambrian time and the Phanerozoic eon.Eras of the Phanerozoic eon include the Paleozoic, Mesozoic, and Cenozoic eras.Each era is divided into one or more periods.
17Geologic Time Notations ya – Years Agomya – Million of years agobya – Billion years agoEons to Eras to Periods once life on EarthTime before life = Precambrian2 Eons Proterozoic and PhanerozoicPhanerozoic = 3 erasPrecambrian Time Paleozoic ERA Mesozoic ERA Cenozoic ERA
18Era word roots Geologist use the clues in some of these words. For example:zoic refers to animal lifepaleo means ancientmeso means middle,ceno means recent.So the relative order of the three youngest eras, first Paleoozoic, then Mesozoic, then Cenoozoic, is straightforward.
19Autotrophic prokaryotes enriched the atmosphere with oxygen. Chapter 14The History of Life14.1 Fossil Evidence of ChangePrecambrianNearly 90 percent of Earth’s entire history, stretching from the formation of Earth to the beginning of the Paleozoic era about 542 million years agoAutotrophic prokaryotes enriched the atmosphere with oxygen.Visualizing Geologic Time
20The first tetrapods emerged in the Devonian. Chapter 14The History of Life14.1 Fossil Evidence of ChangeThe Paleozoic EraThe ancestors of most major animal groups diversified in what scientists call the Cambrian explosion.Life in the oceans continued to evolve at the end of the Cambrian period.Fish, land plants, and insects appeared during the Ordovician and Silurian periods.The first tetrapods emerged in the Devonian.
21Chapter 14The History of Life14.1 Fossil Evidence of ChangeA mass extinction ended the Paleozoic era at the end of the Permian period.Between 60 and 75 percent of the land species alive went extinct and 96 of all marine species. Why were marine organisms more affected?The greatest of the five major mass extinctions was the Permian Mass Extinction .The five major mass extinctions: Ordovician, Devonian, Permian, Triassic and Cretaceous.
22The Mesozoic Era (Triassic, Jurassic, Cretaceous) Chapter 14The History of Life14.1 Fossil Evidence of ChangeThe Mesozoic Era (Triassic, Jurassic, Cretaceous)Mammals and dinosaurs first appeared late in the Triassic period, and flowering plants evolved from nonflowering plants.Birds evolved from a group of predatory dinosaurs in the middle of the Jurassic period.About 65 million years ago, a meteorite struck Earth. A hypothesis that this resulted in the K/T Mass Extinction ending the Cretaceous Period.
23Chapter 14The History of Life14.1 Fossil Evidence of ChangePlate tectonics describes the movement of several large plates that make up the surface of Earth.These plates, some of which contain continents, move atop a partially molten layer of rock underneath them.
25Mammals became the dominant land animals. Chapter 14The History of Life14.1 Fossil Evidence of ChangeThe Cenozoic EraMammals became the dominant land animals.After the mass extinction at the end of the Mesozoic era, mammals of all kinds began to diversify.
2614.2 The Origin of Life Origins: Early Ideas Chapter 14The History of Life14.2 The Origin of LifeOrigins: Early IdeasSpontaneous generation is the mistaken idea that life arises from non-life.Francesco Redi, an Italian scientist, tested the idea that flies arose spontaneously from rotting meat.
27Chapter 14The History of Life14.2 The Origin of LifeThe theory of biogenesis states that only living organisms can produce other living organisms.Louis Pasteur designed an experiment to show that biogenesis was true even for microorganisms.
28Simple organic molecule formation Chapter 14The History of Life14.2 The Origin of LifeOrigins: Modern IdeasSimple organic molecule formationThe primordial soup hypothesis was an early hypothesis about the origin of life.Organic molecules could have been synthesized from simple reactions.UV light from the Sun and electric discharge in lightning might have been the primary energy sources to start the chemical reactions of gases in early atmosphere.
29Chapter 14The History of Life14.2 The Origin of LifeStanley Miller and Harold Urey were the first to show that simple organic molecules could be made from inorganic compounds.Later, scientists found that hydrogen cyanide could be formed from even simpler molecules in simulated early Earth environments.
31Four Requirements of Life Chapter 14The History of Life14.2 The Origin of LifeFour Requirements of LifeSimple organic molecules, the building blocks of life.A way to synthesize proteins from amino acids.A coding system for replicating proteins – such as DNA.A way to form cells from molecules - membranes
32Life requires proteins. Chapter 14The History of Life14.2 The Origin of LifeMaking ProteinsLife requires proteins.One possible mechanism for the formation of proteins would be if amino acids were bound to a clay particle.
33Some RNA sequences appear to have changed very little through time. Chapter 14The History of Life14.2 The Origin of LifeGenetic CodeSome RNA sequences appear to have changed very little through time.Many biologists consider RNA to have been life’s first coding system.Other researchers have proposed that clay crystals could have provided an initial template for RNA replication.
34Scientists hypothesize that the first cells were prokaryotes. Chapter 14The History of Life14.2 The Origin of LifeCellular EvolutionScientists hypothesize that the first cells were prokaryotes.Many scientists think that modern prokaryotes called archaea are the closest relatives of Earth’s first cells.
35Archaea are autotrophic. Chapter 14The History of Life14.2 The Origin of LifeDomain ArchaeaArchaea are autotrophic.They do not obtain their energy from the Sun.Archaea also do not need or produce oxygen.
36Chapter 14The History of Life14.2 The Origin of LifeMany scientists think that photosynthesizing prokaryotes part of evolved not long after the archaea.Prokaryotes, such as cyanobacteria, have been found in rocks as old as 3.5 by.Photosynthesizing bacteria like cyanobacteria dramatically changed the atmosphere – increasing oxygen content for you and I.
37The Endosymbiont Theory Chapter 14The History of Life14.2 The Origin of LifeThe Endosymbiont TheoryThe ancestors of eukaryotic cells lived in association with prokaryotic cells.The relationship between the cells became mutually beneficial, and the prokaryotic symbionts became organelles in eukaryotic cells.This theory explains the origin of chloroplasts and mitochondria.Three properties of chloroplasts and mitochondria shared with prokaryotes: circular DNA, similar ribosomes, reproduced by fission.
38Chapter 14The History of Life14.2 The Origin of Life
39Chapter Resource Menu Chapter Diagnostic Questions The History of LifeChapter Resource MenuChapter Diagnostic QuestionsFormative Test QuestionsChapter Assessment QuestionsStandardized Test Practicebiologygmh.comGlencoe Biology TransparenciesImage BankVocabularyAnimationClick on a hyperlink to view the corresponding lesson.
40Which is an example of the theory of spontaneous generation? Chapter 14The History of LifeChapter Diagnostic QuestionsWhich is an example of the theory ofspontaneous generation?Tadpoles become frogs.A starfish can grow from a severed arm.Damp hay and corn create mice.From a tiny acorn, an oak can grow.
41What gas do scientists think was absent from Earth’s early atmosphere? Chapter 14The History of LifeChapter Diagnostic QuestionsWhat gas do scientists think was absent fromEarth’s early atmosphere?sulfurnitrogenoxygenwater vapor
42In which period did the first land vertebrates appear? Chapter 14The History of LifeChapter Diagnostic QuestionsIn which period did the first land vertebratesappear?CambrianDevonianTriassicMesozoic
43In which type of rock do paleontologists search for fossils? Chapter 14The History of Life14.1 Formative QuestionsIn which type of rock do paleontologists searchfor fossils?igneousmetamorphicsedimentaryvolcanic
44Which dating method determines the age of Chapter 14The History of Life14.1 Formative QuestionsWhich dating method determines the age ofrocks by comparing them to rocks in otherlayers?absolute datinggeological datingrelative datingsedimentary dating
45Which geological change during the Mesozoic Chapter 14The History of Life14.1 Formative QuestionsWhich geological change during the Mesozoicera had the greatest effect in shaping thecourse of evolution?plate tectonicsextensive glaciationincreased volcanic activitymeteorite impact
46At one time people believed that mold growing Chapter 14The History of Life14.2 Formative QuestionsAt one time people believed that mold growingon a piece of cheese was created by thecheese. This is the idea of __________.biogenesistransgenesisprimordial generationspontaneous generation
47According to the endosymbiont theory, what may Chapter 14The History of Life14.2 Formative QuestionsAccording to the endosymbiont theory, what mayhave happened to a prokaryotic cell that entereda host cell?It was digested by the host cell.It became an organelle in the host cell.It became a harmful parasite in the host cell.It was removed from the host cell byexocytosis.
48An ancient prokaryote containing photosynthetic Chapter 14The History of Life14.2 Formative QuestionsAn ancient prokaryote containing photosyntheticpigments that was engulfed by a host cell mayhave become a _________.chloroplastlysosomecentrioleribosome
49Which is the half-life of the radioactive isotope shown in the graph? Chapter 14The History of LifeChapter Assessment QuestionsWhich is the half-life of the radioactive isotopeshown in the graph?18 years36 years54 years72 years
50Study the graph. Determine the age of a rock if it contained 40% C-14. Chapter 14The History of LifeChapter Assessment QuestionsStudy the graph. Determine the age of a rock ifit contained 40% C-14.2,857.5 years7,576 years11,460 years5,730 years
51Use the illustration to infer what Pasteur’s experiment showed? Chapter 14The History of LifeChapter Assessment QuestionsUse the illustration to infer what Pasteur’sexperiment showed?
52Tilted bottles often spill. Microorganisms do not grow in flasks. Chapter 14The History of LifeChapter Assessment QuestionsTilted bottles often spill.Microorganisms do not grow in flasks.Sterile liquids cannot spoil.Microorganisms can enter the tilted flask.
53Which factor made it unlikely that life existed on Chapter 14The History of LifeStandardized Test PracticeWhich factor made it unlikely that life existed onEarth 4 billion years ago?absence of oxygenabsence of foodintense heatintense sunlight
54For which fossil might a paleontologist most Chapter 14The History of LifeStandardized Test PracticeFor which fossil might a paleontologist mostlikely use carbon-14 to determine its age?fossilized microbes in volcanic rockdinosaur footprints found in sedimentaryrockmarine fossils found in a deep sedimentarylayera woolly mammoth frozen in a glacier sincethe last Ice Age
55Beryllium-10 (Be-10) has a half life of about Chapter 14The History of LifeStandardized Test PracticeBeryllium-10 (Be-10) has a half life of about1.5 million years. If a sample is analyzed anddetermined to contain ¼ of the original Be-10,what is the age of the sample?750,000 years3 million years4.5 million years6 million years
56Which provides the best evidence that a Chapter 14The History of LifeStandardized Test PracticeWhich provides the best evidence that ameteorite struck the earth 65 million yearsago?a large crater that was founda layer containing high levels of iridiumthe sudden appearance of mammalsthe sudden disappearance of dinosaurs
57In this experiment using water and the gases to simulate Earth’s early Chapter 14The History of LifeStandardized Test PracticeIn this experimentusing water and thegases to simulateEarth’s earlyatmosphere, whichwas not one of thefinal products?
58amino acids nucleotides RNA molecules sugar molecules Chapter 14The History of LifeStandardized Test Practiceamino acidsnucleotidesRNA moleculessugar molecules
59Why do scientists believe that archea are Chapter 14The History of LifeStandardized Test PracticeWhy do scientists believe that archea arethe closest relatives to Earth’s first cells?They are eukaryotes.They contain DNA.They carry out photosynthesis.They live in extreme environments.
60Glencoe Biology Transparencies Chapter 14The History of LifeGlencoe Biology Transparencies
62Section 1 Vocabulary fossil paleontologist relative dating Chapter 14The History of LifeVocabularySection 1fossilpaleontologistrelative datinglaw of superpositionradiometric datinghalf-lifegeologic time scaleeraperiodCambrian explosionK-T boundaryplate tectonics
63Section 2 Vocabulary spontaneous generation theory of biogenesis Chapter 14The History of LifeVocabularySection 2spontaneous generationtheory of biogenesisendosymbiont theory
64Visualizing Geologic Time Continental Drift Miller-Urey Experiment Chapter 14The History of LifeAnimationVisualizing Geologic TimeContinental DriftMiller-Urey Experiment