Biology 216 Ecology Mark Pyron Professor CL 229 285-8852 [e-mail]

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Biology 216 EcologyMark PyronProfessorCL
229285-8852mpyron_at_bsu.edu
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Syllabus

• Online
• http//mpyron.iweb.bsu.edu/Bio216/outline216.html
• Text is required
• Molles 5th edition
• Attendance is required -

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Assignments

• Reading assignments
• Questions - be prepared!
• I will warn you
• Written assignments

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Cheating

• Zero grade for all involved
• Grade of F in course for cheating on exam

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Exams?

• Short answer
• Matching
• Multiple choice
• Essay questions

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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

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Chap 1What is ecology?

• Many definitions
• Scientific study of the distribution and
  abundance of organisms
• (Andrewartha and Birch)

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Another definition

• study of the structure and function of nature
• (Odum)

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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?

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Ecology is a broad science

• Plants, animals, protists, monera, fungi
• Soils, air, water

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• Physiology, taxonomy, chemistry, geography,
  behavior, etc.

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Why be an ecologist?
Most ecologists develop a love for their
organism, for the environment, and for asking
questions about their system.
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Types of Ecological Studies

• Observational
• Descriptive
• Random sampling or replication
• Describe some aspect of natural world

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Observational

• Based on Representative Samples
• Random sampling from population of interest to
  obtain unbiased information.
• Replication Multiple individuals / areas
  observed to document variation.

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Types of Ecological Studies

• Comparative studies
• What is influence of factor(s)
• Data from natural world

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Hot Environment
Cold Environment
Warm Environment
What is the effect of temperature on the
abundance of ants ?
Comparative Study
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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?

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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.

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Types of Ecological Studies

• Experimental
• Determine effect of treatment
• Randomize individuals or areas
• Replication many samples
• Control

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Controlled Environments
What is the effect of temperature on the
activity of ants ?
Heated Environment
Random Assignment
Observe Compare
Cooled Environment
Experimental Study
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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

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Aquatic Snails in Indiana

• Mark Pyron and Jayson Beugly
• Ball State University
• Department of Biology

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Historic distributions

• Museum records
• University Michigan
• Ohio State University
• gt 100 lots
• Photograph individuals in each collection

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Current distributions

• Visit historic sites
• 100 sites revisited
• 20 new sites
• Collect in all habitats
• Water quality hardness, DO, pH, conductivity,
  Temp

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Sites through-out Indiana Eel River
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Big Blue River at Edinburgh
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E. Fork 14-mile Creek
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E. Fork White River
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Fall Creek in Indianapolis
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Little Turkey Lake near Helmer
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Ohio River at Aurora
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Muscatatuck River
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Campeloma decisum
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Physa acuta
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Lymnaea humilis
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Elimia livescens
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Pleurocera acuta
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Bellamya chinensis
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New Collection Results

• 15,227 individuals in 26 species
• 2.8 species per site
• 144 individuals per site

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Status

• One extinction (Valvata bicarinata)
• 12 imperiled
• 3 vulnerable to extinction
• 9 widespread abundant

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Taxa with highest abundances

• 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

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Species Richness
Lakes in North have higher species richness
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Abundance patterns
Wabash River mainstem has highest abundances
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Results

• Latitude important at regional scale
• Habitat variation and water chemistry important
  at local scale

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Observational, comparative, or experiment?
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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
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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
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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)

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Role of evolution theory in ecology

• 1. What is evolution?
• Changes in populations of organisms over time
• Includes changes in gene frequencies genetic

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Role of evolution theory in ecology

• 2. How does natural selection work?
• Cruel world
• Genetic variation
• Differential survival and repro
• Genes for advantageous traits spread

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Role of evolution theory in ecology

• 3. Some characteristics (traits) are best
  available for survival and reproduction (NOT the
  BEST)
• In a given environment

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Evolution change in organisms with
generations
not changes in communities ( extinctions or more
species)
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Adaptation allow organisms to survive
reproduce - design of organisms.
Darwin woodpecker example
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Woodpecker adaptations

• Beak, tongue,
• tail, toes

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Natural selection

• Some individuals survive and produce more
  offspring than others.
• Their traits work better in that environment.

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On what level does natural selection act?

• Individuals?
• Species?
• What entity evolves over time?

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Pioneering ecological study

• Robert MacArthur
• 5 forest warblers found in same forest
• How do they all live in same environment if they
  are all same size and all eat insects?

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MacArthur

• Divided trees into zones
• Recorded time that 5 species spent in zones

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MacArthur results

• Birds divided tree into zones
• Appears to reduce competition

Fig 1.2
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Further studies confirmed that competition maintai
ns feeding zones experimentally
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Field studies can be combined with lab experiments

• Answer more detailed questions
• Field natural settings
• Lab controlled environment

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Ecologists use available tools

• Can include behavior physiology,
• Or, geology paleontology
• Etc., depending on the question