Ecology: The Study of Organism Interactions and Adaptations

Ecology

The scientific study of how organisms interact with each other and with their non-living environment.

Ecological Niche

The manner in which an organism uses the resources in, and is influenced by the conditions of its habitat.

Habitat

The physical place, or type of place, where an organism lives.

Physical Adaptation

Genetically-inherited characteristics that enable a given organism to survive and reproduce using a given niche.

Niche Partitioning

The division of niches between species so as to cut down on competition.

Resource

A material that is used, and potentially used up.

Environmental Conditions

Background features of the habitat.

Fundamental Niche

The largest array of resources an organism can utilize.

Realized Niche

The actual set of resources utilized.

Hardy Equilibrium Conditions

1. There must be no random events that differentially eliminate alleles.
2. There must be no migration into or out of the population.
3. There must be no reproductive or survival advantage to any gene or genotype.
4. All mating must occur at random.
5. Mutations may not occur.

Gene Pool

All of the inheritable alleles found within a given population.

Allele Frequency

Numeric rate at which a gene (or allele) occurs in a gene pool, relative to the other alleles in its gene pair.

Genetic Diversity

The variety of genes and genotypes in a gene pool.

Genetic Drift

Changes in gene (allele) frequency owing to random factors.

Gene Flow

Movement of genes into or out of population resulting from migration.

Environmental Selection

Conditions of habitat create differential survival and replication of specific alleles.

Mutation

An alteration to the nucleotide sequence of a gene.

Evolution

Changes in gene frequencies in populations over time.

Evolutionary Fitness

The ability of an organism or allele to survive and reproduce.

Species

A population of organisms which is reproductively isolated from other populations of organisms.

Speciation

The evolution of reproductive isolation in two populations which previously interbred.