Download Chapter 18

Ecology Unit
Part 1:
Introduction to Ecology
Objectives
• Identify a key theme in ecology
• Describe an example showing the
effects of interdependence upon
organism in their environment
• Identify the importance of models to
ecology
• State the five different levels of
organization at which ecology can be
studied
Questions to Answer
•
•
•
•
•
What is ecology?
How did the science ecology come about?
What does it involve?
Are there sub-sciences within this field?
What are the important themes?
What is Ecology?
• It is the study of:
– interactions of organisms with one
another
– interactions of organisms with their
environment
What is the History of Ecology?
• Founder of ecology:
– Theophrastus in 320 BC
• Term was first coined in 1866
• Scientists that contributed to the science
of ecology
– Carl Linnaeus
– Charles Darwin
– Alexander von Humboldt
– Carl Ludwig Wildenow
– Rachel Carson
– Edward O. Wilson
What does Ecology Involve?
1. Collecting information about organisms and
their environments
2. Observing and measuring interactions
3. Looking for patterns & seeking to explain
them
What are the Sub-Sciences of
Ecology?
1. Ecophysiology
– which is the study of interrelationships
between the physiology of organisms and
their environment
2. Population ecology
– which is the study of the interactions
between populations of organisms and
their environment
What are the Sub-Sciences of
Ecology?
3. Community ecology
– which is the study of the interactions
between communities of organisms and
their environment
4. Ecosystem ecology
– which is the study of the interactions
between ecosystems of organisms and
their environment
What are the Themes of Ecology?
1. Interdependence
2. Species borders
– interaction with the environment can
limit the development of the species
• For example:
– Urban landscaping
– Human activity within the environment
Interdependence
• Is a key theme in ecology
• It is the interconnectedness of organisms to
their surroundings both living and nonliving
• An organism’s survival depends on its ability
for interdependence
Some Examples of Interdependence
• Rhinos and oxpeckers
• Humans & plants
– Humans need oxygen from the plant
– Plants need carbon dioxide from us
•
•
•
•
•
Remoras and sharks
Clownfish & sea anemones
Elephants & mud
Bees & flowering plants
Yellow tangs & sea turtles
Effects of Interdependence
• Any change in the environment can
spread through the network of
interactions and cause serious damage
• Examples:
• the spread of Lyme Disease
• Pollution
• Overhunting
• Pesticides
Ecological Models
• Ecology is extremely complex and
difficult to study
• Scientist use ecological models to
represent or describe the components
of an ecological system
• It helps them to make predicts about
possible changes
• Models can be physical, conceptual, or
mathematical
• But models can be limited in their
application
Levels of Organization
•
•
•
•
•
•
Biosphere
Ecosystem
Community
Population
Organism
What do these levels consist of?
What is an Organism?
• Any form of life that exhibits the
characteristics of life:
– Response to stimuli
– Growth & development
– Homeostasis
– Metabolism
– Changes over time
– Cells & organization
Organism Classification
• All organisms are classified by the science of
taxonomy
• Each organism usually has a two word name
consisting of its genus and species
classification
• For example:
– Homo sapiens = human
– Drosophila melanogaster = fruit fly
– Bison bison = American bison or buffalo
Organism Classification Cont.
• However, some organisms have a subspecies
name, which is a lower classification of a
geographically isolated species that is
genetically unique from the main species
population
• For example:
– Canis lupus
• Has 40 subspecies including domestic dogs,
dingoes, and other wolves
• Canis lupus nublius = Great Plains Wolf
• Canis lupus familaris = domestic dog
• Canis lupus dingo = dingo
What is a Population?
• A group of organisms of the same species
living in a certain area
– Example: Duckweed
• A population must also be able to interbreed
• It can be the organisms of one species in a
large geological area
– Example: Elephant herd in Africa
• Or it can be used to describe all the
organisms of a species on Earth
– Example: World population of humans
What is a Community?
• Is a group populations of different
species that interact with other and live
in a specific area
Ways a Community Interacts
• Competition-populations compete for
resources
• Predation-some organisms are food for other
organisms
• Mutualism-an interaction between organisms
in which both benefit
• Neutral-when two species do not interact at
all
• Commensalism-one organism benefits and the
other is not benefitted nor harmed
• Parasitism-one organism benefits and the
other is harmed
What is an Ecosystem?
• Includes all the organisms and the
nonliving environment in a particular
place
• For example: a pond ecosystem
– Living components (biotic factors):
• fish, turtles, plants, algae, insects and
bacteria
– Nonliving components (abiotic factors):
• pH of the pond, levels of dissolved
oxygen and carbon dioxide, supply of
nitrogen and the amount of sunlight
Coral Ecosystem
What is a Biosphere?
• This is the broadest level of
organization
• The term was coined by Vladimir
Vernadsky in 1929
• It is the part of the earth and its
atmosphere in which living organisms
exist or that is capable of supporting
life
The Biosphere