Dr. Thomas M. Gehring Room 181 Brooks Hall 774-2484 tom.gehring@cmich

Dr. Thomas M. GehringRoom 181 Brooks Hall

[email protected]

http://www.cst.cmich.edu/users/gehri1tmOffice Hours: MW 2 to 4 pm or by appointment

Welcome!BIO 340 – General Ecology

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

Biological Disciplines Relating To Ecological Study

EVOLUTIONEVOLUTION

BEHAVIOBEHAVIORR

GENETICSGENETICS

PHYSIOLOGYPHYSIOLOGY

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 ResourcesMacArthur (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

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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?

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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 WorldBiosphere

Landscape

Ecosystem

Community

Population

Individual

Organ

Tissue

Cell

Organelle

Atom

INCREASED KNOWLEDGEINCREASED KNOWLEDGE

INCREASED COMPLEXITYINCREASED 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 StudyTypes of Ecological Study

• AUTECOLOGY– Study of

individuals– Physiology

/Environment

Types of Ecological StudyTypes 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

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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

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Percentage of feeding bites0 20 40

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• 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.