Lecture 1:  The Scope of Ecology


	Dr. Judith Bronstein, Associate Professor
	Bio Sci West 420	621-3534	JLB@ccit.arizona.edu
	Office Hours: Tuesday 1:30-2:30, Friday 11-12


MAKE SURE YOU UNDERSTAND CAN DEFINE ALL THE UNDERLINED TERMS.

Hierarchy of Biological Organization:  each level contains all the levels listed 
above it.
Cell
Individual
Population: a group of organisms of the same species that are found together 
and are capable of interbreeding

Community:  a group of species living together in the same area, that are 
capable of interacting with each other

Ecosystem:  the organisms found in a particular habitat, along with the 
physical environment they inhabit

Biome:  one of earthÕs major divisions of characteristic communities.

Natural history:  observations of organisms in their environment.

Ecology:  the scientific study of interactions between organisms and their 
environment.  Oriented towards testing hypotheses.

Basic ecology:  asks fundamental questions without a ÒpracticalÓ goal in mind 
(though the answers may have practical applications)

Applied ecology:  takes basic ecology and applies it to issues of human 
concern:  effects of pollution, how to conserve endangered species, etc.

Kinds of questions ecologists ask about different levels of biological organization:
Individual level:
What kinds of adaptations help organisms survive in their biotic and abiotic environments?
adaptation:  a particular feature of an organism that increases the likelihood 
that it can survive and reproduce in a particular habitat.
biotic environment:  biological aspects of the habitat (e.g., diseases, predators)
abiotic environment: non-biological aspects of the habitat (e.g., climate, soil)

Population level:
What are the gene frequencies within a given population (population genetics)?
What determines how fast a population grows and shrinks (population 
dynamics), and how can we measure this?
density-independent factors:  factors that affect population dynamics without 
respect to population density (e.g., hurricanes, earthquakes)
density-dependent factors:  factors that affect population dynamics differently 
depending on how dense the population is (e.g., competition for food)
	
Community level:
How do species interact (predation, competition, mutualism, etc.), and has 
evolution modified these interactions?  That is, has there been coevolution?	
Are there properties of communities that we wouldnÕt expect based on 
studying their component species in isolation:  that is, is there community 
structure?