General Ecology 3130 Exam One

Ecology

a field of scientific study of the processes influencing the distribution and abundance of organisms and the interactions among organisms

Distribution

the location of organisms

Abundance

the number of individuals present at a particular time and place

Interactions

actions or behaviors among individuals or between an individual and its environment

Abiotic Factors

nonliving elements of an ecosystem

Biotic Factors

living elements of an ecosystem

Environmentalism

a set of ethics and beliefs that is verified through affirmation

Organizational Hierarchy

a system of grouping organisms in a nested order

genes > individuals > populations > communities > ecosystems > biosphere

Why is Ecology done?

identify patterns in the distribution and abundance of organisms, understand the mechanisms that produce observed patterns, and predict responses to natural and manmade environmental change

Observation / Natural Experimentation

a method of ecological research that examines variation in some pattern or process across a naturally existing gradient of interest - factors not influenced by the researchers involved

represents natural system dynamics but lacks true control and cannot establish causation

Manipulative Experimentation

a method of ecological research in which researchers place experimentally-induced variations in a lab or field setting

limits confounding and is capable of establishing causation

Models and Simulations

a method of ecological research that uses conceptual and mathematical representations of ecological relationships

useful for generating hypotheses but is often an oversimplification of reality and cannot establish causation

Confounding

Additional factors of an experiment that are not accounted for that may be affecting experiment results

Continuous Variables

variables that can be expressed numerically

Categorical Variables

variables that can be expressed in groups

When to use Correlation or Regression Tests

in scatter plots comparing two continuous variables

When to use T-Tests or ANOVA Tests

in bar graphs comparing a continuous and categorical variable

Does correlation show causation?

no

Independent Variable

the naturally existing or experimentally-induced difference in experimental units

Dependent Variable

the measured response to differences in naturally existing or experimentally-induced differences in experimental units

Experimental Unit

the smallest repetitive unit in which data is being measured from

Evolution

changes in the composition of a population from one generation to the next

Common Garden Experiment

subjects are removed from their natural habitats and studied in a regulated environment to eliminate environmental differences from affecting test results

Charles Darwin and Alfred Russel Wallace

proposed the theory of evolution

Requirements of Evolution Through Natural Selection

there must be variation among individuals at a genetic and phenotypic level

at least some variation must be heritable - offspring resemble their parents

some variations are more advantageous than others and are more likely to pass on to the next generation - selective reproduction

Gregor Mendel

studied genetic inheritance

Gene

a segment of DNA that carries genetic information

Allele

variations of a gene

Genotype

an individual's unique combination of alleles

Phenotype

the observable expression of an individual's alleles

Fitness

the measure of an individual's reproductive success compared to others in its population

Adaptation

traits that have evolved by natural selection to increase an individual's fitness

Local Adaptation

traits that have evolved by natural selection to increase an individual's fitness that are specific to the individual's unique environment

Genetic Drift

a method of evolution in which the change of a population over time is through chance and not selective

Founder Effect

a form of genetic drift in which a sample establishes a new population, carrying its own composition of alleles that differs from the original population

Bottleneck Effecr

a form of genetic drift in which the size of a population is severely reduced through a random event, resulting in survivors that have a different composition of alleles than the original population

Migration

the movement of individuals or samples between populations

Mutation

a copying error within an individual's DNA that can create new alleles, introducing variation within a population

Heterozygous Genotypes

having two different alleles for a gene

Homozygous Genotypes

having two identical alleles for a gene

Natural Selection

a method of evolution in which some traits are associated with greater fitness and become more common over time