EBIO 1220 1st Edition Lecture 5 Outline of Last Lecture I. Isolationa. Reproductive Isolationb. When Populations Come Back TogetherII. Pre-Zygotic Isolating MechanismsIII. Post-Zygotic Isolating MechanismsIV. Allopatric vs. Sympiatric IsolationV. Evolutionary History of Life Outline of Current Lecture II. The Geologic RecordIII. Three Major Eonsa. Archaeanb. Proterozoicc. Phanerozoici. Overviewii. Paleozoiciii. Mesozoiciv. CenozoicIV. Three Major Extinctionsa. Permianb. Cretaceousc. Current V. Naming and Classifying OrganismsVI. PhylogenyCurrent LectureII. The Geologic Recorda. Data from fossils in sedimentary rocki. Radioactive Dating: decay of radioactive isotopesb. Information is incomplete and imperfect i. Not all forms of life leave fossilsIII. Three Major Eonsa. Archaeani. Lasted approximately 2 billion yearsThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.ii. From the beginning of the solar system (4600 mya (million years ago)) and lasts until 2500 myaiii. Very little diversityiv. All unicellular organismsv. Mostly single-celled bacteriab. Proterozoici. Beginning 2500 mya and lasts until 542 myaii. Multicellular organisms evolveiii. Flora and Fauna evolveiv. No terrestrial lifev. All life lives in aquatic habitatsvi. Multicellular organisms took over 3 billion years to evolve1. Oxygen levels were rising which may have favored multicellularity during this time2. Multicellular trait must have existed before as a mutationc. Phanerozoici. Overview1. From 542 mya until the present day2. First terrestrial life3. Bursts of incredible diversification4. Lots of extinction and speciation ii. Paleozoic1. Starts w/ Cambrian explosion and ends with Permian Extinction2. Cambrian Explosion: burst of speciation in relatively small amount of evolutionary timea. Lots of continental drifi. Environmental changes, isolation, and ecological changes lead to increased diversityiii. Mesozoic1. Age of reptiles2. Starts w/ Cretaceous extinction3. Cretaceous Extinction: flowering plants (angiosperms) appear and diversify and most dinosaurs go extincta. Doomed many marine and terrestrial organisms (most notably the dinosaurs)b. Thought to have been caused by the impact of a large meteorc. Possibly led to the rise of mammalsi. Previously mammals were mostly underground dwellersii. Extinction of predators led to diversificationiv. Cenozoic (current)1. Humans diverged from other hominids fairly recentlya. The “Sixth Mass Extinction” eventi. 100-1000x baseline for extinctionii. Predicted that 25% of all species will be extinct by 2020iii. Humans have had the largest impact of any other species on evolutionary historyIV. Three Major Extinctionsa. Permianb. Cretaceousc. Current V. Naming and Classifying Organismsa. Taxonomy: naming and classifying of species and groups of speciesb. Systematics: the study of this biological diversity in an evolutionary context. Involves building phylogenetic treesc. Hierarchical classification schemei. Speciesii. Genusiii. Familyiv. Orderv. Classvi. PhylumVI. Phylogenya. Evolutionary history of a group that is illustrated by an evolutionary treei. This is a hypothesis about the relationships among groups and changes when new data is foundb. New species discovered in 2014!i. Hardy bacterium (Tersicoccus phoenicis) survives in places where food is virtually nonexistent and can withstand the heat of spacecraf clean-rooms, drying, UV light, and hydrogen peroxideii. Interesting to scientists b/c it lives in such extreme conditionsiii. Could help with finding life on other planetsc. Phylogenies are importanti. Better understanding of disease transmission by giving insight into origins and predicting future movement1. SARS, HIV, and Avian Influenza are examplesii. Conservationiii. Understanding origins of life and