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Ecology BIO 340. What is Ecology The scientific study of the interactions that determine the distribution and abundance of organisms. Introduction. What is not ecology?. Biological Disciplines Relating To Ecological Study. PHYSIOLOGY. BEHAVIOR. GENETICS. Applied Ecology; Management.
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Ecology BIO 340 • What is Ecology • The scientific study of the interactions that determine the distribution and abundance of organisms
Introduction • What is not ecology?
Biological Disciplines Relating To Ecological Study PHYSIOLOGY BEHAVIOR GENETICS Applied Ecology; Management EVOLUTION
18th Century Thomas Malthus Exponential Growth
19th Century Natural History Human Demography
Ernst Haeckel • Defined “ecology” • Coined phrase “ontogeny recapitulates phylogeny” • Studied Foraminiferans • Controversial ideas
20th Century • Lotka & Volterra (1920’s) • Model population growth • Gause (1920’s) • Manipulative Experiments
20th Century • Leopold (1930’s) • Natural Resources • MacArthur (1960’s) • Mathematical Ecology • Geographical Ecology
20th Century • Lindeman (1942) • Trophic Dynamics • Hutchinson (1950’s) • Niche Concept
20th & 21st Century ? • Charles Krebs • Populations/Cycles • Monica Turner • Landscape • Ecology • BIO 340 Student
Introduction • Major Questions • Where are organisms found? • Where aren’t organisms found?
Introduction • Major questions • How many are found there?
Introduction • Major questions • Why are organisms found here and not there? alvar
Introduction • Levels to ask questions • Individuals • Behavior • Physiology
Introduction • Levels to ask questions • Populations • Change in size • Temporal & Spatial
Introduction • Levels to ask questions • Communities • Biotic interactions
Introduction • Levels to ask questions • Ecosystems • Community & Physical Environment
Introduction • Levels to ask questions • Landscapes • Spatial patterns
Introduction • Levels to ask questions • Biosphere
Organization of Biological World INCREASED KNOWLEDGE Biosphere Landscape Ecosystem Community Population Individual Organ Tissue Cell Organelle Atom INCREASED COMPLEXITY
Types of Ecological Study • AUTECOLOGY • Study of individuals • Physiology /Environment
Types of Ecological Study • SYNECOLOGY • Study of groups of organisms • Community level and above
Introduction • How to look at a question • Proximate explanation
Introduction • How to look at a question • Ultimate explanation “Nothing in biology makes sense except in the light of evolution” Theodosius Dobzhansky
Introduction • Major Advances • Mathematical Models
Introduction • Major Advances • Evolution
Introduction • Major Advances • Hypothesis Testing • Testing ideas about how the natural world works • A hypothesis is developed to explain an observed phenomenon. • Example: giraffes have long necks because the long necks enable them to reach food that is unavailable to others.
Testing Ideas about How the Natural World Works • Null Hypothesis • Hypothesis of no difference • Example: The length of a giraffe’s neck does not influence the height at which it forages. • Alternative Hypothesis • Example: The length of a giraffe’s neck does influence the height at which it forages.
Most feeding is done below neck height. Males Females 7 7 6 6 5 5 4 4 Feeding height (meters) 3 3 2 2 1 1 0 0 0 20 40 0 20 40 Percentage of feeding bites
Testing Ideas about How the Natural World Works • Null Hypothesis • Hypothesis of no difference • Example: The length of a giraffe’s neck does not influence the height at which it forages. ACCEPT • Alternative Hypothesis • Example: The length of a giraffe’s neck does influence the height at which it forages. REJECT
Testing Ideas about How the Natural World Works • Null Hypothesis • Hypothesis of no difference • Example: The length of a giraffe’s neck does not influence the height at which it forages. ACCEPT • So why do they have such long necks? • Alternative hypotheses • suggest a different explanation • Example: giraffes have long necks because long necks are effective weapons for one male against another during mating (Simmons and Scheepers).
Hypothesis Testing and Experimentation • Testing Ideas about How the Natural World Works • The predictions made by each hypothesis are determined • Observations are made and/or an experiment is designed to obtain data regarding the predictions