Ecology BIO 340 What is Ecology The scientific

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 Applied Ecology; Management

18 th Century Thomas Malthus Exponential Growth

19 th Century Natural History Human Demography

Ernst Haeckel • Defined “ecology” • Coined phrase “ontogeny recapitulates phylogeny” • Studied Foraminiferans • Controversial ideas

20 th Century • Lotka & Volterra (1920’s) Model population growth • Gause (1920’s) Manipulative Experiments

20 th Century Leopold (1930’s) Natural Resources Mac. Arthur (1960’s) Mathematical Ecology Geographical Ecology

20 th Century Lindeman (1942) Trophic Dynamics Hutchinson (1950’s) Niche Concept

20 th & 21 st 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 Biosphere Landscape INCREASED KNOWLEDGE Ecosystem Community Population Individual Organ Tissue Cell INCREASED COMPLEXITY Organelle Atom

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. Feeding height (meters) Males Females 7 7 6 6 5 5 4 4 3 3 2 2 1 1 0 0 0 20 40 0 20 Percentage of feeding bites 40

• 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