BIO 211 Chapter 1, Fall 2018

Chapter 01 Lecture Outline Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 1 See separate PowerPoint slides for all figures and tables pre-inserted into PowerPoint without notes and animations. The Science of Biology Chapter 1 2 3 The Science of Life • Biology unifies much of natural science • Life defies simple definition – Living systems are the most complex chemical systems on Earth – Life is constrained by the properties of chemistry and physics • Science is becoming more interdisciplinary – Combining multiple fields 4 • 7 characteristics of all living organisms 1. Cellular organization 2. Ordered complexity 3. Sensitivity 4. Growth, development, and reproduction 5. Energy utilization 6. Homeostasis 7. Evolutionary adaptation • Living systems show hierarchical organization – Cellular level • Atoms, molecules, organelles, cells • Cell is the basic unit of life – Organismal level • Tissues, organs, organ systems 5 6 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Atoms Molecule Macromolecule CELLULAR LEVEL Organelle Cell 0.2 µm O C H N O H N C O (organelle): © Dr. Donald Fawcett & Porter/Visuals Unlimited; (cell): © Steve Gschmeissner/Getty Images 7 Tissue Organ 100 µm ORGANISMAL LEVEL Organ system Organism (tissue): © Ed Reschke; (organism): © Russell Illig/Getty Images RF Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. – Populational level • Population, community – Ecosystem level – Biosphere • Earth is an ecosystem we call the biosphere • Each level has emergent properties – Result from interaction of components – Cannot be deduced by looking at parts themselves – “Life” is an emergent property 8 9 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. POPULATIONAL LEVEL Population Species Community Ecosystem Biosphere (population): © George Ostertag/agefotostock; (species): © PhotoDisc/Volume 44 RF; (community): © Ryan McGinnis/Alamy; (ecosystem): © Robert and Jean Pollock; (biosphere): NASA 10 The Nature of Science • Science aims to understand the natural world through observation and reasoning • Science begins with observations, therefore, much of science is purely descriptive – Classification of all life on Earth – Human genome sequencing 11 • Science uses both deductive and inductive reasoning • Deductive reasoning uses general principles to make specific predictions • Inductive reasoning uses specific observations to develop general conclusions 12 • Scientists use a systematic approach to gain understanding of the natural world – Observation – Hypothesis formation – Prediction – Experimentation – Conclusion 13 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Observation Question Potential hypotheses Remaining possible hypotheses Last remaining possible hypothesis Hypothesis 1 Hypothesis 2 Hypothesis 3 Hypothesis 4 Hypothesis 5 Hypothesis 2 Hypothesis 3 Hypothesis 5 Hypothesis 5 Reject hypotheses 1 and 4 Experiment Reject hypotheses 2 and 3 Experiment Modify hypothesis Experiment 4 Experiment 1 Predictions Experiment 2 Experiment 3 Predictions confirmed 14 • A hypothesis is a possible explanation for an observation • A hypothesis – Must be tested to determine its validity – Is often tested in many different ways – Allows for predictions to be made • Iterative – Hypotheses can be changed and refined with new data 15 • Experiment – Tests the hypothesis – Must be carefully designed to test only one variable at a time – Consists of a test experiment and a control experiment 16 • Predictions – Hypotheses should make predictions – Predictions provide a way to test the validity of hypotheses – Hypothesis must be rejected if the experiment produces results inconsistent with the predictions – The more experimentally supported predictions a hypothesis makes, the more valid the hypothesis 17 • Scientific theory – Is a body of interconnected concepts – Is supported by much experimental evidence and scientific reasoning – Expresses ideas of which we are most certain • Compare to general meaning of theory – Implies a lack of knowledge or a guess 18 Darwin and Evolution • Example of how a scientist develops a hypothesis and a theory gains acceptance • Charles Darwin served as naturalist on mapping expedition around coastal South America • 30 years of observation and study before publishing On the Origin of Species by Means of Natural Selection 19 Voyage of the HMS Beagle Copyright © The McGraw-Hill Companies, Inc. 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NORTH PACIFIC OCEAN Marquesas Society Islands Straits of Magellan Cape Horn Tierra del Fuego SOUTH ATLANTIC OCEAN New Zealand Hobart King George’s Sound Mauritius Bourbon Island NORTH PACIFIC OCEAN Philippine Islands British Isles Western Isles EUROPE ASIA Madagascar Friendly Islands Equator NORTH AMERICA Galápagos Islands NORTH ATLANTIC OCEAN Cape Verde Islands Canary Islands AFRICA Sydney AUSTRALIA INDIAN OCEAN Cape of Good Hope Falkland Islands Valparaiso SOUTH AMERICA Port Desire Buenos Aires Montevideo Keeling Islands Bahia Ascension St. Helena Rio de Janeiro • Darwin was not the first to propose evolution – Living things have changed over time • Darwin’s contribution was a mechanism – Natural selection 20 • On the Beagle, Darwin saw that characteristics of similar species varied from place to place • Galápagos Finches – 14 related species differ only slightly – “Descent with modification” or evolution 21 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Woodpecker Finch (Cactospiza pallida) Large Ground Finch (Geospiza magnirostris) Cactus Finch (Geospiza scandens) 22 • Darwin studied Thomas Malthus’s An Essay on the Principle of Population – Populations of plants and animals increase geometrically – Humans can only increase their food supply arithmetically – Populations of species remain constant because death limits population numbers • Darwin saw that although every organism has the potential to produce more offspring, only a limited number do survive and reproduce themselves 23 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 2 6 18 54 4 6 8 geometric progression arithmetic progression 24 • Evidence supporting Darwin’s theory has only grown – Fossil record • Transitional forms have been found at predicted positions in time – Earth’s age • Physicists of Darwin’s time were wrong • Earth is very old – 4.5 billion years old – Mechanism for heredity • Mendel’s laws of inheritance were unknown to Darwin – Comparative anatomy • Vertebrate forelimbs all share the same basic array of bones • Homologous – same evolutionary origin but now differ in structure and function • Analogous – structures of different origin used for the same purpose (butterfly and bird wings) 25 26 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Human Cat Porpoise Horse Bat 27 – Molecular Evidence • Compare genomes or proteins of different organisms • Phylogenetic trees – based on tracing origin of particular nucleotide changes to reconstruct an evolutionary history Human Rhesus Dog Frog Bird Number of Amino Acid Differences in a Hemoglobin Polypeptide 10 20 30 70 60 0 40 50 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Unifying Themes in Biology • Cell theory – All organisms composed of cells – Cells are life’s basic units – All cells come from preexisting cells 28 a. b. 60 µm 500 µm Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. a: © Dennis Kunkel/Phototake; b: © Karl E. Deckart/Phototake • Molecular basis of inheritance – Deoxyribonucleic acid (DNA) – Sequence of 4 nucleotides encode cell’s information – Gene – discrete unit of information – Genome – entire set of DNA instructions – Continuity of life depends on faithful copying of DNA into daughter cells 29 • Structure and function – Study structure to learn function – Know a function – look for that structure in other organisms – Example • Receptor on human cell for insulin known • Find similar molecule in a worm • Might conclude this molecule functions the same in the worm 30 • Diversity of life arises by evolution – Underlying unity of biochemistry and genetics argues for life from the same origin event – Diversity due to evolutionary change over time – 3 domains • Bacteria – single-celled prokaryote • Archaea – single-celled prokaryote • Eukarya – single-celled or multicellular eukaryote 31 32 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Eukarya Plantae Fungi Animalia Protista (plantae middle): © David M. Dennis/Animals Animals; (plantae right): © Corbis/Volume 46 RF; (fungi left): © Royalty Free/Corbis; (fungi middle): © Mediscan/Corbis; (fungi right): © PhotoDisc BS/Volume 15 RF; (animalia left): © Royalty-Free/Corbis; (animalia middle): © Tom Brakefield/Corbis; (animalia right): © PhotoDisc/Volume 44 RF; (protista left): © Corbis/Volume 64 RF; (protista middle): © Tom Adams/Visuals Unlimited; (protista right): © Douglas P. Wilson/Frank Lane Picture Agency/Corbis • Evolutionary conservation – All organisms today descended from a simple creature 3.5 BYA – Some characteristics preserved – use of DNA – Conservation reflects that they have a fundamental role 33 • Cells are information-processing systems – Information in DNA used to direct synthesis of cellular components • Control of gene expression leads to different cells/ tissue types – Cells process environmental information • Glucose levels, presence of hormones – Cells in multicellular organisms must coordinate with each other 34 • Nonequilibrium state – Living systems are open systems – Constant supply of energy needed – Self-organizing properties at different levels – Emergent properties from collections of molecules, cells, and individuals 35