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

The loss of genetic diversity due to a sharp decline in a population’s size

Species diversity

The number of species in a region or 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 the the area of the island

Ecological tolerance / fundamental niche

The suite of abiotic conditions under which a species can survive, grow, and reproduce

Realized niche

The range of biotic & abiotic 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

Disruptions that occur regularly, such as day/night cycles and tides

Episodic disruption

Disruptions that occur somewhat regularly, such as cycles of rain that happen every few years

Random disruption

Disruptions that occur with no regular pattern, such as natural disasters

Resistance

A measure of how much a disruption can affect the flow of energy and matter in an ecosystem

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

Artificial selection

The process in which humans determine which individuals to breed

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

Random selection

The processes that alter the genetic composition of a population over time

Mutation

Any change to an organism’s DNA

Gene flow

The process by which individuals move from one population to another

Genetic drift

A change in the genetic composition of a population over time due to random mating

Founder effect

A change in the genetic composition of a population as a result of them descending from a small number of colonizing individuals

Speciation

The formation of new and distinct species

Allopatric speciation

Speciation that occurs due to geographic isolation

Sympatric speciation

Speciation that occurs without geographic isolation

Genetically modified organism (GMO)

An organism produced by copying genes from one organism into another

Ecological succession

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

Primary succession

Ecological succession occurring on surfaces with bare rock & no soil

Pioneer species

Species that are able to survive with little or no soil, the main kind involved in primary succession

Mid successional plants

Plants with deep root systems that are able to take advantage of open, sunny areas despite the poor soil conditions

Secondary succession

The succession of plant life that occurs in disturbed areas that haven’t lost their soil

Climax community

A community that has reached 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

Endemic species

Species that live in a very small area of the world and nowhere else

Biodiversity hotspots

Isolated areas that are home to many endemic species, containing a high proportion of all species found on Earth