AP Environmental Science Unit 2

Genetic diversity

Measure of the genetic variation among individuals in a population

Species diversity

Indicates the number of species in a region or a particular ecosystem

Habitat diversity

The variety of habitats in an 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 abiotic or biotic conditions

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

Provisional services

Goods produced by ecosystems that humans can use directly

Regulating services

Natural ecosystems help to regulate environmental conditions

Supporting systems

Support services that would be extremely costly for humans to generate

Cultural services

Cultural or aesthetic benefits to people

Island biogeography

The study of how species are distributed and interacting on islands

Species-area curve

How species on an island increase with the area of the island

Ecological tolerance/fundamental niche

The suite of abiotic conditions under which a species can survive

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

Resistance

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

Immediate 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

Microevolution

At the population level

Macroevolution

Gives rises to new species, classes, etc

Evolution by artificial selection

Humans decide which species grow/evolve

Evolution by natural selection

Environment decides which species grow/reproduce

Fitness

Individual’s ab8ility to adapt and survive

Adaptation

Trait that improves individual’s fitness

Geneflow

Individuals move from one population to another and lter the genetic composition of both

Genetic Drive

Change in the genetic coposition of a population over time asw a result of random mating

Bottleneck effect

A population experiences a drastic reduction in genetic diversity when the size of a population is reduced

Allopatric speciation

Spciation with genmetic isolation

Sympatric speciation

Speciation without genetiac isolationGene

Genetically modified organism (GMO)

An organism produced by copying genes from a species with some desirable trait and inserting them into other species

Ecological succession

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

When succession begins with bare rock and no soil

Pioneer species

 Organisms that can survive with little to no soil

Secondary succession

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 isn’t very abundant but has large effects on an ecological community

Indicator species

Used to quickly characterize when ecosystems have been negatively impacted by humans