Unit 2- The Living World: Biodiversity

Adaptation

Any inherited trait (physical or behavioral) that increases an organism's ability to survive and/or reproduce.

Allele

An alternative form of a gene; brown eyes vs green eyes.

Anthropogenic

Caused by humans.

Biodiversity hotspot

An area that has an exceptionally high amount of different species and is prioritized by conservationists for preservation.

Biological diversity

The overall variety of living things in an area.

Biomass

The total amount of living tissue in a trophic level or in an ecosystem.

Bottleneck effect

A reduction in the genetic diversity of a population caused by a sudden reduction in the population size.

Camouflage

The ability of an organism to blend into its surroundings.

Climax community

A stable, mature community that occurs at the "end" of succession.

Cultural services

Aesthetic, spiritual, or recreational benefits from nature.

Disturbance

Any event that results in changes in an ecosystem.

Ecological tolerance

The range of conditions in which a species can survive.

Ecology

The study of how living things interact with each other and their environment.

Ecosystem diversity

Variety of habitats within an area.

Ecosystem services

Benefits provided to humans by the natural world.

Endemic species

Organisms that are native to and only found in one area.

Episodic

Occurring at irregular intervals.

Evolution

The gradual change in a species over time.

Extinction

Process of all of a species dying out worldwide.

Extirpation

"Localized extinction" where all of a species disappears from a certain area only.

Fitness

The ability of an organism to survive and reproduce.

Flow rate

The speed & volume of water that moves through an area.

Gene

A segment of DNA that codes for a specific trait; "hair color" or "sickle cell anemia".

Generalist species

Organisms with a broad ecological niche- they can live in many different places, eat a variety of foods, and tolerate a wide range of environmental conditions.

Genetic diversity

The variety of DNA within populations in an area.

Geographic isolation

Physical separation of individuals in a population that can lead to an accumulation of genetic differences between the groups.

Geological time

Periods, epochs, and eras of millions of years used to study changes in the earth over its entire history.

Habitat

The place where an organism lives.

Indicator species

Organisms that by their presence or abundance provide information about the health of the environment.

Intermediate Disturbance Hypothesis

The concept that moderate levels of disturbance can foster greater species diversity than low or high levels of disturbance.

Invasive species (AKA Introduced, Non-native, or Exotic Species)

Species that enter new ecosystems either from intentional or accidental introduction and outcompete native organisms causing an ecosystem imbalance.

Island Biogeography

Proposes that the number of species found on an undisturbed island is determined by colonization and extinction rates; highest biodiversity will be on a larger size island that is closer to the mainland.

Keystone species

Organisms that have an unusually large impact on the ecosystem; not necessarily the most abundant organism in the ecosystem.

Lichen

Symbiotic relationship between a fungus and a photosynthetic organism that is able to grow on bare rock and act as a pioneer species.

Mass extinction

An event in which many (50-90%) species all die out at once, due to a change in the climate, a massive volcano, a meteor impact, or human influence.

Migration

Movement of organisms from one area to another, typically seasonally.

Mimicry

Ability of an organism to look like another organism.

Mutation

Any change in DNA that might have a positive, negative, or no effect.

Native species

Those organisms that are naturally found in an area.

Natural selection

The principle that since not all organisms will survive and reproduce, those that are well-suited to their environment will be most likely to survive and pass on their genes.

Opportunistic species

Species that can quickly inhabit a new area and take advantage of new resources.

Periodic

Occurring at regular, fixed intervals.

pH

The measure of how acidic or basic something is, obtained by measuring the concentration of hydrogen ions.

pH scale

Measurements from 0-14 with smaller numbers being more acidic and larger numbers being more basic/alkaline.

Phylogeny

The evolutionary history of a group of species showing how they are related.

Pioneer species

The first species to populate an area during the process of succession.

Primary succession

Series of changes in an environment that does not have any living organisms or soil present.

Provisioning services

Products that are obtained from nature, such as food or lumber.

Random

Occurring with no pattern whatsoever.

Regulating services

Ways that nature controls the environment to maintain conditions, such as climate and water quality.

Salinity

Measure of amount of salts dissolved in water.

Sea level

The average height of the ocean's surface at a given time.

Secondary succession

Series of changes that occur in an ecosystem that has been disrupted but still has soil and living organisms present.

Specialist species

Organisms with a narrow ecological niche- they can only live in one place, eat few foods, and tolerate a narrow range of environmental conditions.

Speciation

The formation of a new species.

Species diversity

The variety of different kinds of organisms that are in a community.

Species evenness

The relative abundance of different species in a community; the proportions of each.

Species richness

The number of different species that are present in a community.

Succession

A series of predictable change occurring in an area after it has been disturbed.

Supporting services

Benefits from nature that allow us to live, such as nutrient cycling and soil formation.