1. Introduction to Ecology [BIO 3510]

2. Origin of the word “ecology”
Greek origin
OIKOS = household
LOGOS = study of…
Study of the “house/environment” in which we live.

3. Definitions
the study of relationships of organisms to their environment and to one another.
a branch of science describing, explaining and predicting where organisms live (distribution and abundance).
literally means the study of ‘houses’, ‘home conditions’, ‘habitats or more broadly ‘environment’ of plants and animals.
according to Crebs (1972), “Ecology is the scientific study of the interactions that determine the distribution and abundance of organisms”
systems are dynamic, not static.

4. What is Ecology?
The study of interactions that take place between organisms and their environment.
It explains how living organisms affect each other and the world they live in.
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5. Habitat & Niche Habitat is the place a plant or animal lives
Niche is an organism’s total way of life
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6. History of Ecology
In 1859, a French Zoologist St. Hilaire, had employed the word ‘ethology’ for the study of organisms in relation to their environment.
The term ‘ecology’ was first defined by a German biologist Ernst Haeckel in 1866.
The term ‘ecology’ is derived from the Greek word ‘Oikos-meaning ‘house or dwelling place and ‘logos’ meaning discourse.

7. Ecology - A Science for Today!
We have a great need for ecological understanding:
what are the best policies for managing our environmental support systems -- our watersheds, agricultural lands, wetlands?
we must apply ecological principles to:
solve or prevent environmental problems
inform our economic, political, and social thought and practice.

8. Ecology and Environmentalism
Ecology is a science and is different from environmentalism.
Ecology provides the science behind many questions related to human impacts on the environment but it is not the same as environmentalism.
Environmentalism is an advocacy or concern for the environments.
However, most ecologists would tend to support efforts to protect natural systems and restore degraded environments

9. Scopes of Ecology:
Interactions determine distribution and abundance of organisms.
Two main themes in ecology are:
Where do organisms live? & Why?
How many organisms are present? & Why?
By understanding the principals of ecology we can then apply them to management of both plants and animals
By studying ecology, we expect to be carried through the sequence i.e. observation, explanation, hypothesis, experiment and conclusion where we are now on the path to understanding.
We are not only interested in the structure of the population or community but also how it functions. In other words, we are interested in “cause and effect”.

10. Divisions of Ecology: Divisions of Ecology
Autecology- ecological study of individual species
Synecology – ecological study of a population of a species growing together or communities.

11. How Ecologists Study the Natural World
Ecologists, like other scientists, employ a scientific method:
observation and description of natural phenomena
development of hypotheses or explanations
testing the predictions of these hypotheses
We test hypotheses because many explanations are plausible (reasonable). Which is best?

12. Ecology Employs the Scientific Method
Induction
Observation
Hypothesis
or model
Experiment
Prediction
Deduction

13. Observing Experimenting Modeling What species live here?
How many individuals of species are there?
Experimenting
Used to test a hypothesis
Ex - making artificial environments in the lab
Modeling
Making models to gain insight into complex phenomena
Ex. - Global warming

14. What is an hypothesis?
An hypothesis is an idea about how the world works:
e.g., “Frogs sing on warm nights after periods of rain.”
We often wish to understand two components of such a phenomenon:
how? (encompasses physiological processes)
why? (encompasses costs and benefits of the behavior to the individual)

15. Experiments test predictions.
Hypotheses generate predictions:
if observations confirm the prediction, the hypothesis is strengthened
if observations fail to confirm the prediction, the hypothesis is weakened (or rejected)
Best tests of hypotheses are experiments:
independently manipulate one/few variables
establish appropriate controls.

16. Methods to Study Ecology
Theoretical
Mathematical models
Laboratory
Highly controlled but lack realism
Field
Highly realistic but may lack control.

17. Mathematical models are powerful tools:
researcher portrays system as set of equations
model is an hypothesis and yields predictions that can be tested.
examples include:
models of disease spread
models of global carbon

18. Field Study