Ecology is defined as the study of the interactions between
organisms and their environment (including other organisms).
However, ecology also provides great insight into the
evolutionary histories of species, and provides contemporary
examples of factors that influenced historical evolutionary
The distribution of organisms is affected by many factors, but
these are generally classified as one of two types: biotic or
abiotic factors. The combined effects of these factors define
the earth's biomes, or large-scale ecosystems, in which the
earth's species live.
- Understand what biotic and abiotic factors are.
- Comprehend how ecology influences evolutionary pathways.
- Be able to describe how a rain shadow affects regional
- Understand how biogeography is influenced by evolution,
ecology, and geologic history.
- Be familiar with the general characteristics of several
common aquatic and terrestrial biomes.
- Understand how temperature and light are stratified in
certain aquatic and terrestrial biomes.
Behavior refers to an organism's coordinated response to
environmental stimuli. Generally, we think of behavior as a
characteristic of animals (although it could be argued that
other types of organisms also have perhaps simpler forms of
behavior). Different types of behavior generally fall into two
categories: innate, or genetically controlled, and learned. In
this lesson you will learn about different types of animal
behavior, but keep in mind also how behavior influences the
interactions within ecosystems, and ultimately the evolutionary
pathways of different types of organisms.
- Be able to define behavior.
- Understand the difference between innate and learned
behaviors, and give examples of each.
- Understand the differences between habituation,
associative learning and cognitive learning, and be able to
give examples of each.
- Be familiar with different types of social behaviors.
It is important to view ecology not just as interactions
between individuals and their environment, but also as
interactions between entire populations and their
environment. The field of population ecology attempts to
discern how environments ultimately affect the life history
characteristics of populations. Life history characteristics
include such things as migration habits or lack thereof,
feeding habits, reproductive strategies, demographics, etc.
Population ecology often begins with simple measures of
population size and density, but can quickly become
complicated when trying to discern all of the factors acting
on a population and their relative importance.
- Define the terms 'population' and 'population ecology'.
- Define 'life history'.
- Understand the measures of population size and density.
- Understand K vs. r selection strategies and give actual
examples of both.
- What are 'demographics'?
- Explain the difference between the exponential and
logistical growth models.
- Describe the concept of an ecological footprint at the
individual and population level.
In ecology, a community is the specific assemblage of species
inhabiting an ecosystem. The interactions between the members of
a community can take many forms, from predation to mutualism.
All of these interactions, however, continue to drive the
selective forces which ultimately lead to evolutionary change.
In this lesson, you will learn about the basic types of
interactions found between species in ecological communities,
and how these interactions may influence a community over time.
- Understand what competition is in ecological terms, and
how it influences both communities and evolutionary
- Understand the concepts of competitive exclusion and
- Be able to describe examples of aposematic coloration,
Batesian and Mullerian mimicry.
- Be able to define trophic structure.
- Describe different types/levels of environmental
disturbance, and give examples of each.
- Be familiar with the concept of environmental
All ecosystems share three things in common: water, energy and
inorganic elements. You spent plenty of time learning about
water in Biology 115, so we will focus here on energy and
inorganic elements. Energy from the sun fuels virtually all
ecosystems on our planet - this energy is fixed by
photosynthetic organisms and transferred through food webs by
herbivory, predation and decomposition. Inorganic elements,
however, come from the air and the soil, and are converted into
organic compounds using the energy of the sun. In this lesson,
we will describe the basic flows of energy and nutrients within
and through ecosystems, and how these processes may affect the
organism living within an ecosystem.
- Describe how the flow of energy and the flow of nutrients in
ecosystems is both similar and different.
- Be able to describe what primary production is, and what
types of factors control primary production in aquatic and terrestrial
- Understand the concept of trophic efficiency, and why
energy is transferred less efficiently between higher levels
of food chains.
- Describe the nitrogen cycle.
- Understand how biological magnification works, how it
relates to trophic efficiency, and how it can affect
organisms at higher levels of food chains.