Introduction to Ecology

Introduction to Ecology Session 1 – Introduction to the Study of Ecology

The Science of Ecology Goals for the day • Differentiate Between Ecology and Environmentalism and Conservation Biology • Trace History of Ecological Thought • Define Ecology Scientifically • Learn the Scientific Method • Organization of Ecology

Ecology vs Environmentalism • Scientific societies and activist groups – often in conflict with each other • Earth First, Greenpeace, and WWF • Industry – e.g., GMO’s: Pandora’s box or chicken little? • Individuals vs populations • Hawaii: PETA vs Nature Conservancy or

Hawaii: PETA vs Nature Conservancy • Feral pigs (Sus scrofa) • Integral part of native Hawaiian Luau culture • Introduced by both Polynesians and Europeans (2 spp) • Rooting destroys many plants • Create wallows, water collects, and encourages mosquitoes to breed

Hawaii: PETA vs Nature Conservancy • Nature Conservancy • Attempting to eradicate the pig from their lands • Uses ecological impact of pigs as justification for their removal • Capture through noose snare-trapping, as this is the easiest way to capture the animals

Hawaii: PETA vs Nature Conservancy • PETA • Recognizes the impact that these pigs have on the ecology • Snare-trapping is protracted, inhumane, and a painful way to kill them • Advocates for humane trapping and then quick kills • Ignores financial cost

Hawaii: PETA vs Nature Conservancy • Resolution? • Still to be found • Nature Conservancy continues to trap • A few write-ups of the controversy are available from the Honolulu Advertiser • A more general discussion of invasives in Hawaii is availble from USGS

Key Distinctions • Ecology is a science • Our focus in this course • Environmentalism is a cause • With our without scientific backing • Conservation Biology is the integration of these two • Using science to support a political cause

History of Ecological Thought • From Thoreau to modern times • Historically has been literature-based appreciation of nature • Subsequently became more of a descriptive science

Darwinian References • “…how infinitely complex and close-fitting are the mutual relations of all organic beings to each other and to their physical conditions of life.” • Origin of Species

Definition of Ecology • “To determine the factors that have produced the present distribution and abundance of organisms” • (Jonathan Krebs, 1972)

Factors Influencing Organismal Distribution and Abundance • Abiotic • Climate • Topography • Latitude • Altitude • Biotic • Intraspecific Interactions • Interspecific Interactions

Scientific Method and Hypothesis Testing • Goals: • Judge good science • Hudson River PCB dredging • Electromagnetic radiation and cancer • Sea otters, killer whales and overfishing • Do good science

Goals of science • Describe the patterns that are found in the natural world • Purely descriptive in nature • Historically this was “ecology”, a.k.a. naturalism • Make up explanations and then stop there • Test Explanation of Patterns • This is the major emphasis of most of what we usually call “science” • Key component: TEST these explanations! • How to test these explanations? • The Scientific Method

Methods of Explanation • Include those of descriptive science • Approximately 11 Steps • Process is repeated many times • Can NEVER prove a hypothesis • Can only reject many, leaving one as best supported by the data • “Proof” is a common fallacy • Centerpiece of this method are Hypotheses

Types of Hypotheses • Null hypothesis • The hypothesis of no change • Often abbreviated as Ho • Alternative hypotheses • Often abbreviated as Ha, Hb, etc. • All must be mutually exclusive (including the null) • We accept an Ha if Ho is first statistically rejected • Which Ha to accept is determined by trends in data

Scientific Method - Steps 1-5 • Observe or suspect pattern • Posit cause or significance of observed difference • Create answerable question to explain pattern • Create testable hypotheses • Null (Ho ) and alternate hypotheses (Ha) • Design experiment

Scientific Method - Steps 6-11 • Collect data (descriptive stage) • Analyze data, primarily using statistics • Evaluate hypotheses, reject Ho? • Make conclusions based on data • Note problems in current work • Predict future directions for research

An Exercise… • Come up with an observation that you’ve seen recently and work through how you would implement the above 11 steps

Parts of a scientific report • Title • Abstract - an overall summary • Introduction - background, question, Has • Methods - what we did • Results - what we found, analyses results • Discussion - interpretations, predictions • Acknowledgements - who helped us • References - who we cited

Transmission Methods in Science • Written report (articles, chapters, books) • Traditional • Oral presentation • Commonly used for preliminary presentation of work to get feedback before writing it up • Poster • Visual summary of work - used at conferences • Web page • Can use a written report & make it interactive

How to Evaluate Science? • Do the data address the question? • Is there enough data to support the claim? • Has the study been replicated elsewhere? • Are alternative interpretations considered? • Is it peer-reviewed? • Is it presented objectively? • Are there real controls?

What is the Organization of Ecology? • Ranges widely from individual to biosphere studies • Most of ecology happens in the current time • Proximate Explanations • Only a few fields (e.g., evolutionary ecology and paleoecology) are concerned with past environments and historical time • Ultimate Explanations

Proximate Fields • Emphasis of this course • Examples, by scale • Population • Growth rates, PVA, Population genetics, Metapopulation analyses, etc. • Community • Interspecific interactions, Environmental impact statements, etc. • Ecosystem • Energy, Matter, Nutrient flow, Pollution,

Ultimate Fields • Evolutionary Ecology • Using trees of relationship (phylogenies) to address ecological questions • E.g., evolution of swordtail length and preference in platys • Behavioral Ecology • Comparing a few closely related species to address ecological questions • Paleoecology • Attempting to recreate the ecology of ancient times • One of the goals is to recreate the ancient environment in which the lineages may have evolved

Population Community Ecosystem Proximate Fields Revisited • Trends down pyramid: • Increase in geographicscale • From single species to multiple species • Increasing number of ecological factors that may be influential • Decreasing certainty in results

Assignment for Next week: • Establish your Ecological Footprint • How much of an impact you have on the planet • Instructions are all online, and available here • Turn in at beginning of class • We will discuss it then

Next Week: The Tour of the Basic Fields of Ecology Begins • Population ecology • Next week’s emphasis • Community ecology • Ecosystem ecology • Conservation Issues • Application of above to real world problems

Introduction to Ecology