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Welcome! BIO 340 – General Ecology. Dr. Thomas M. Gehring Room 181 Brooks Hall 774-2484 tom.gehring@cmich.edu http://www.cst.cmich.edu/users/gehri1tm Office Hours: MW 2 to 4 pm or by appointment. Wildlife Ecology Research at CMU.
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Welcome! BIO 340 – General Ecology Dr. Thomas M. Gehring Room 181 Brooks Hall 774-2484 tom.gehring@cmich.edu http://www.cst.cmich.edu/users/gehri1tm Office Hours: MW 2 to 4 pm or by appointment
Wildlife Ecology Research at CMU • Develop & test tools that might lead to a successful coexistence of humans & wildlife
Wildlife Ecology Research at CMU • Current studies examining population & spatial ecology of carnivores • Current tests of various non-lethal management tools on wolves
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 EVOLUTION
18th Century Thomas Malthus Exponential Growth
19th Century Natural History Human Demography
Ernst Haeckel • Defined “ecology,” “phylum” • 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
21st Century ? • 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
Figure 1.1 “…the community is an abstraction representing a level of organization rather than a discrete unit of structure in ecology.”
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. • Conclusion: the observational data support the Sexual Selection hypothesis.