Download The Science of Ecology

Introduction to Ecology
Session 1 – Introduction to the
Study of Ecology
The Science of Ecology
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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
The Science of Ecology
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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
The Science of Ecology
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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
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 closefitting are the mutual
relations of all
organic beings to
each other and to
their physical
conditions of life.”
– Origin of Species
The Science of Ecology
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•
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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
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
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Climate
Topography
Latitude
Altitude
• Biotic
– Intraspecific Interactions
– Interspecific Interactions
The Science of Ecology
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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
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
1. Observe or suspect pattern
2. Posit cause or significance of observed
difference
3. Create answerable question to explain
pattern
4. Create testable hypotheses
– Null (Ho ) and alternate hypotheses (Ha)
5. Design experiment
Scientific Method - Steps 6-11
6. Collect data (descriptive stage)
7. Analyze data, primarily using statistics
8. Evaluate hypotheses, reject Ho?
9. Make conclusions based on data
10. Note problems in current work
11. 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
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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?
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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?
The Science of Ecology
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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
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
Proximate Fields Revisited
• Trends down pyramid:
– Increase in geographic scale
Population
– From single species to multiple
species
Community
– Increasing number of ecological
factors that may be influential
Ecosystem
– 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