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Biology 216 Ecology Mark Pyron Professor CL 229 285-8852 mpyron@bsu.edu. Syllabus. Online: http://mpyron.iweb.bsu.edu/Bio216/outline216.html Text is required: Molles 5th edition Attendance is required -. Assignments:. Reading assignments Questions - be prepared! I will warn you
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Biology 216 EcologyMark PyronProfessorCL 229285-8852mpyron@bsu.edu
Syllabus Online: http://mpyron.iweb.bsu.edu/Bio216/outline216.html Text is required: Molles 5th edition Attendance is required -
Assignments: Reading assignments Questions - be prepared! I will warn you Written assignments
Cheating • Zero grade for all involved • Grade of F in course for cheating on exam
Exams? • Short answer • Matching • Multiple choice • Essay questions
Objectives • Students will be able to describe the nature and scope of Ecology • Students will be able to explain the role of Evolution theory in Ecology • Students will be able to describe how ecologists gain knowledge
Chap 1What is ecology? Many definitions: “Scientific study of the distribution and abundance of organisms” (Andrewartha and Birch)
Another definition: “study of thestructure and function of nature” (Odum)
Ecology tries to explain the patterns that you find in the real world: Why are plants and animals where they are, and how many are there in those locations?
Ecology is a broad science: Plants, animals, protists, monera, fungi Soils, air, water
Why be an ecologist? Most ecologists develop a “love” for their organism, for the environment, and for asking questions about their system.
Types of Ecological Studies • Observational • Descriptive • Random sampling or replication • Describe some aspect of natural world
Observational • Based on Representative Samples • Random sampling from “population of interest” to obtain “unbiased” information. • Replication: Multiple individuals / areas observed to document variation.
Types of Ecological Studies • Comparative studies • What is influence of factor(s) • Data from natural world
Hot Environment Cold Environment Warm Environment What is the effect of temperature on the abundance of ants ? Comparative Study
Comparative Studies • Purpose: To determine the influence of one or more “factors” on some aspect of the natural world. • Compare samples from populations, communities, ecosystems – do they change with the factor?
Disadvantage of Comparative Studies • Many environmental factors differ among any two natural communities. • Difficult to know if observed differences in the “response” variable are caused by the “treatment” variable or by some other factor.
Types of Ecological Studies • Experimental • Determine effect of treatment • Randomize individuals or areas • Replication = many samples • Control
Controlled Environments What is the effect of temperature on the activity of ants ? Heated Environment Random Assignment Observe Compare Cooled Environment Experimental Study
Experimental Studies • Purpose: To obtain most definitive evidence that “treatment” causes “response”, Test Cause-Effect Hypotheses. • Main Difference From Comparative Studies: Investigator imposes treatment on study subjects. • Can be done in Lab or Field
Aquatic Snails in Indiana Mark Pyron and Jayson Beugly Ball State University Department of Biology
Historic distributions • Museum records • University Michigan • Ohio State University • > 100 lots • Photograph individuals in each collection
Current distributions • Visit historic sites • 100+ sites revisited • 20 new sites • Collect in all habitats • Water quality: hardness, DO, pH, conductivity, Temp
New Collection Results • 15,227 individuals in 26 species • 2.8 species per site • 144 individuals per site
Status • One extinction (Valvata bicarinata) • 12 imperiled • 3 vulnerable to extinction • 9 widespread + abundant
Elimia livescens Physa spp. Pleurocera acuta Fossaria spp. Pleurocera canaliculata Stagnicola elodes Lymnaea catascopium Campeloma spp. 10,564 1,769 990 759 279 108 103 96 Taxa with highest abundances
Species Richness Lakes in North have higher species richness
Abundance patterns Wabash River mainstem has highest abundances
Results • Latitude important at regional scale • Habitat variation and water chemistry important at local scale
Experimental Design: Part 1 Equivalent Groups: Similar as possible BEFORE imposing treatment. Stronger evidence that differences between groups are caused by treatment. Random Assignment of Study Subjects /Areas to Treatment Groups Replication: Multiple Study Subjects Assigned to Each Treatment Group
Experimental Design: Part 2 Differences observed between groups caused by treatment, NOT other factors. Differences observed between groups would NOT have happened without treatment. Control of all non- treatment factors to be same for all experimental groups Comparison of groups that received different treatments to determine response
Limitations of Experiments • Subjects in controlled experimental conditions may not respond the same as when they are in their natural setting (Less Realistic). • Some subjects very difficult to study in controlled settings (Lions, Trees, Communities, Ecosystems)
Role of evolution theory in ecology • 1. What is evolution? • Changes in populations of organisms over time • Includes changes in gene frequencies = genetic