2Earth’s History Earth’s history is long and fascinating. There have been great biological and geological changes
3Fossil RecordsThe fossil record provides strong evidence of the evolution of lifeTriceratops
4Nicholas StenoEarth’s history has been unveiled by scientists applying the tools of critical thinkingNicholas Steno was a Danish theologianFirst to suggest that fossils had once beenliving organismsDeveloped the Principles of Original Horizontality,Superposition, and Lateral Continuity
5James Hutton Scottish naturalist and physician Father of geologic time Proposed that geologic time was indefinitely longBelieved the Earth was self-renewing (basis of rock cycle)Formulated the principle of uniformitarianism
6Charles Lyell British lawyer Father of Modern Geology Wrote Principles of GeologyPopularized Principle of UniformitarianismDeveloped the Principles of Cross-cutting Relationships and Inclusions
7Charles Darwin English naturalist and geologist Studied Lyell’s Principles of GeologyWrote On the Origin of Species by Means of Natural SelectionCredited with the Theory of Evolution
8Natural SelectionAll living things develop over time from a very few simple formsAll individuals survive equallyConditions change and only well-adapted individuals surviveNew generation is dominated by well-adapted individualsCan you think of a change in conditions that might lead to natural selection?
9FossilsFossils are the remains of animals and plants, or traces of their presence, that have been preserved in the crust.Fossils preserve a record of past life.
10How Are Fossils Made?Fossilization is the process that turns a once-living thing into a fossil.The Fossil record is biased. Rapid burial is required. In most cases just shell, teeth, and bones are preserved.Preservation is typically by: replacement or formation of a mold or cast.
11Rare, soft part preservation Brachiopod shellsRare, soft part preservation(dinosaur skin)Are these molds or casts or both? Is there evidence of replacement here?
12There are several lines of evidence for evolution PhylogenyPhylogeny is the history of organismal lineages as they change through time. What are some of the changes evident in the phylogeny of the horse?
14Vestigial StructuresHow does the existence of vestigial structures support the concept of evolution?
15EmbryologyEven distantly related organisms have similar embryonic forms that can be traced back to their evolutionary history
16Molecular biology also provides evidence of evolution Changes within separate populations of the same species result in new species through natural selection.Genetic Mutation(random changes to RNA or DNA)Genetic Variation(differences in inherited traits)
17Molecular biology documents the relationship of living organisms to their ancestors
18Parasitic microbes, viruses, bacteria ... all evolve!
19ExtinctionsMass extinctions are dramatic events in the otherwise slow process of evolutionWhich of the Phanerozoic extinctions had the greatest impact on marine organisms? Which one lead to the extinction of the terrestrial dinosaurs?
20ExtinctionDuring a mass extinction large numbers of species die out within a relatively short period of time.
21There are various hypotheses for each mass extinction ...
22Geologic Time ScaleThe Geologic Time Scale is the “calendar” of events in Earth’s historyGeologic Column Drag and DropGeologic Column Drag and Drop Animation
23Hadean Eon Heating of the interior Magma “ocean” “Iron Catastrophe” Eventual coolingEarliest crust and oceansEnded ~ 3.8 byaBegan ~ 4.6 byaExtraterrestrial barrageAtmosphere rich in methane, ammonia and carbon dioxideWhy was the Earth so much hotter during the Hadean than it is now?
24Archean and Proterozoic cratons (i.e., continent crustal blocks) The Archean and Proterozoic Eons lasted from 3.8 million to 542 million years agoArchean and Proterozoic cratons (i.e., continent crustal blocks)
25Archean EonAtmosphere noxious to modern organisms (methane, ammonia, carbon dioxide, and water vapor)More extraterrestrial bombardmentMore volcanic outgassingContinental Cratons formAbundant life first appears (stromatolites)Photosynthesis initiatedThe atmosphere of the Archean would have been noxious to us. What component of our atmosphere would have been noxious to the Archeans?Ancient and modern stromatolites
26Proterozoic EonContinents develop, clustered together (Rodinia) in the southern hemisphereMountain buildingAtmosphere becomes gradually more oxygenatedDiversification of soft-bodied organisms
27Phanerozoic Eon ~ 542 mya to present Includes the Paleozoic, Mesozoic and Cenozoic erasMajor mountain-building eventsPangaea continues break up into modern continentsComplex life evolves with much diversificationGeographic separation isolates some populationsPunctuated by mass extinctionsTiktaalik roseae - a critical transitional organism from Canada’s Arctic
28In the Paleozoic Era complex life evolved and the continents reorganized
29The Cambrian Explosion Organisms that evolved during the Cambrian Explosion, developed some of the basic inherited traits that are still present today, and others that vanished forever.
30Steven EarleSteven EarleSteven EarleSteven EarleWhat is so important about the fossils of the Burgess Shale in the Canadian Rockies?
31In the Mesozoic Era biological diversity increased and continents reorganized yet again