APES Unit 2 Vocab

Biodiversity

The diversity of life forms in an environment.

Genetic diversity

A measure of the genetic variation among individuals in a population.

Population bottleneck

When a large population declines in number, the amount of genetic diversity carried by the surviving individuals is greatly reduced.

Species diversity

The number of species in a region or in a particular ecosystem.

Habitat diversity

The variety of habitats that exist in a given ecosystem.

Specialists

Species that only live under a narrow range of biotic or abiotic conditions.

Generalists

Species that can live under a wide range of biotic or abiotic conditions.

Ecosystem diversity

The variety of ecosystems that exist in a given region.

Species richness

The number of different species in a given area.

Species evenness

The relative proportion of individuals within the different species in a given area.

Ecosystem services

The processes by which life-supporting resources such as clean water, timber, fisheries, and agricultural crops are produced.

Provision

A good produced by an ecosystem that humans can use directly.

Aquaculture

The farming of fish, shellfish, and seaweed.

Island biogeography

The study of how species are distributed and interacting on islands.

Species-area curve

A description of how the number of species on an island increases with the area of the island.

Ecological tolerance

The suite of abiotic conditions under which a species can survive, grow, and reproduce. Also known as fundamental niche.

Realized niche

The range of abiotic and biotic conditions under which a species actually lives.

Geographic range

Areas of the world in which a species lives.

Mass extinction

A large number of species that went extinct over a relatively short period of time.

Periodic disruption

Occurring regularly, such as the cycles of day and night or the daily and monthly cycles of the moon’s effect on ocean tides.

Episodic disruption

Occurring somewhat regularly, such as cycles of high rain and low rain that occur every 5 to 10 years.

Random disruption

Occurring with no regular pattern, such as volcanic eruptions or hurricanes.

Resistance

In an ecosystem, a measure of how much a disruption can affect the flows of energy and matter.

Resilience

The rate at which an ecosystem returns to its original state after a disruption.

Intermediate disturbance hypothesis

The hypothesis that ecosystems experiencing intermediate levels of disturbance will favor a higher level of diversity of species than those with high or low disturbance levels.

Evolution

A change in the genetic composition of a population over time.

Microevolution

Evolution at the population level.

Macroevolution

Evolution that gives rise to new species, genera, families, classes, or phyla.

Evolution by artificial selection

The process in which humans determine which individuals to breed, typically with a preconceived set of traits in mind.

Evolution by natural selection

The process in which the environment determines which individuals survive and reproduce.

Fitness

An individual’s ability to survive and reproduce.

Adaptation

A trait that improves an individual’s fitness.

Evolution by random processes

The processes that alter the genetic composition of a population over time, but the changes are not related to differences in fitness among individuals.

(Mutation, Gene Flow(move), Genetic Drift(Rand mating), Bottleneck effect, founder effect)

Allopatric speciation

The process of speciation that occurs with geographic isolation.

Sympatric speciation

The evolution of one species into two species, without any geographic isolation.

Genetically modified organism (GMO)

An organism produced by copying genes from a species with some desirable trait and inserting them into other species of plants, animals, or microbes.

Ecological succession

The predictable replacement of one group of species by another group of species over time.

Primary succession

Ecological succession occurring on surfaces with bare rock and no soil.

Pioneer species

In primary succession, species that can survive with little or no soil.

Secondary succession

The succession of plant life that occurs in areas that have been disturbed but have not lost their soil.

Climax community

Historically described as the final stage of succession.

Keystone species

A species that is not very abundant but has large effects on an ecological community.

Indicator species

A species that demonstrates a particular characteristic of an ecosystem.