NRS Exam 1

NRS Chapter 1-4 Terms

Biological Diversity

The complete range of species, biological communities, and their ecosystem interactions and genetic variation within species. Also known as biological diversity.

Biodiversity

The complete range of species, biological communities, and their ecosystem interactions and genetic variation within species. Also known as biological diversity.

Normative Discipline

A discipline that embraces ethical commitment rather than ethical neutrality

Environmentalism

A widespread movement, characterized by political activism, with the goal of protecting the natural environment.

Preservationist Ethic

A belief in the need to preserve wilderness areas for their intrinsic value

Resource Conservation Ethic

Natural resources should be used for the greatest good of the largest number of people for the longest time.

Sustainable development

Economic development that meets present and future human needs without damaging the environment and biodiversity.

Land ethic

Aldo Leopold’s philosophy advocating human use of natural resources that is compatible with or even enhances ecosystem health.

Ecosystem management

Large-scale management that often involves multiple stakeholders, the primary goal of which is the preservation of ecosystem components and processes.

Biophilia

The postulated predisposition in humans to feel an affinity for the diversity of the living world.

Conservation Biology

Scientific discipline that draws on diverse fields to carry out research on biodiversity, identify threats to biodiversity, and play an active role in the preservation of biodiversity.

Population

A geographically defined group of individuals of the same species that mate and otherwise interact with eachother.

Ecosystem

A biological community together with its associated physical and chemical environment.

Community

An assemblage of interacting populations of different species living in a particular area.

Species diversity

The entire range of species found in a particular place

Genetic Diversity

The range of genetic variation found within a species

Ecosystem diversity

The variety of ecosystems present in a place or geographic area

Morphospecies

Individuals that are probably a distinct species based on their appearance but that do not currently have a scientific name

Morphological definition of species

A group of individuals, recognized as a species, that is morphologically, physiologically, or biochemically distinct from other groups (compare w/ biological definition of species)

Taxonomists

Scientists involved in the identification and classification of species

Biological definition of species

Among biologists, the most generally used of several definitions of “species”. A group of individuals that can potentially breed among themselves in the wild and that do not breed with individuals of other groups(Compare w/ morphological definition of species)

Hybridize

Interbreeding between different species

Evolutionary definition of species

A group of individuals that share unique similarities of their DNA and hence their evolutionary past

Binomial

The unique two-part Latin name taxonomists bestow on a species, such as Canis lupus (Gray Wolf) or Homo sapiens (Humans)

Cryptic species

Two or more species that have similar appearance but that are genetically distinct

Hybrids

Intermediate offspring resulting from mating between individuals of two different species

Functional diversity

The diversity of organisms categorized by their ecological roles or traits rather than their taxonomy

Species richness

The number of species found in a community

Alpha diversity

The number of different species in a community or specific location; species richness

Gamma diversity

The number of species in a large geographic area

Beta diversity

Rate of change of species composition along a gradient or transect (Divide gamma diversity by alpha diversity)

Shannon diversity index

A species diversity index that takes into account the numbers of different species and their relative abundance

Alleles

Different forms of the same gene

Locus

DNA sequences on a chromosome that code for specific proteins (also called loci)

Mutations

Changes that occur in genes and chromosomes, sometimes resulting in new allele forms and genetic variation

Transposable element

Segment of DNA capable of changing its location on a chromosome, sometimes resulting in a different trait appearing

Recombination

Mixing of the genes on the two copies of a chromosome that occurs during meiosis

Gene pool

The total array of genes and alleles in a population

Genotype

Particular combination of alleles that an individual possesses.

Phenotype

The morphological, physiological, anatomical, and biochemical characteristics of an individual that result from the expression of its genotype in a particular environment.

Biogeographic Barrier

Factors in an environment that prevent the exchange of species among regions

Polymorphic genes

Within a population, genes that have more than one form or allele

Heterozygous

Condition of an individual having two different allele forms of the same gene

Homozygous

Condition of an individual having two identical allele forms of the same gene

Genetic Structure

Patterns of genotypes within and among populations

Environmental DNA (eDNA)

DNA shed into the environment by organisms and that is detected with genetic techniques.

Biological Community

A group of species that occupies a particular locality

Biota

A region’s plants and animals

Habitat

The location or type of environment in which a specific animal or plant species lives

Limiting resource

Any requirement for existence whose presence or absence limits a population’s size (Ex. water in a desert)

Competition

A contest between individuals or groups of animals for resources. Occurs when individuals or a species use a limiting resource in a way that prevents others from using it

Predation

Act of killing and consuming another organism for food

Predators

An animal species that consumes other animals to survive. Also called a secondary consumer or predator. (*Compare with* primary consumers)

Prey

An animal that is eaten as food by another species.

Herbivory

Predation on plants

Carrying capacity

The number of individuals or biomass of a species that an ecosystem can support

Mutualism

When two species benefit each other by their relationship

Symbiotic

A mutualistic relationship in which neither of the two species involved can survive without the other

Trophic levels

Levels of biological communities representing ways in which energy is captured and moved through the ecosystem by the various types of species.Organisms such as green plants, algae, and seaweeds that obtain their energy directly from the sun via photosynthesis. Also known as autotrophs.A species that eats plants or other photosynthetic organisms. Also called a primary consumer.An animal species that consumes other animals to survive. Also called a secondary consumer or predator. *Compare with* primary consumers.A species that feeds or grows on dead plant and animal material. Also called a detritivore

Primary producers

Organisms such as green plants, algae, and seaweeds that obtain their energy directly from the sun via photosynthesis. Also known as autotrophs

Herbivores

A species that eats plants or other photosynthetic organisms. Also called a primary consumer

Primary consumers

A species that eats plants or other photosynthetic organisms. Also called a herbivore

Carnivores

An animal species that consumes other animals to survive. Also called a secondary consumer or predator. (*Compare with* primary consumers)

Secondary consumers

An animal species that consumes other animals to survive. Also called a secondary consumer or predator. (*Compare with* primary consumers)

Tertiary consumers

The fourth trophic level, in which predators eat other predators

Omnivores

Species that eat both plants and animals

Parasites

Organisms that live on or in another organism (host), receiving nutritive benefit while decreasing the fitness of the host, which remains alive

Pathogens

Disease-causing organisms

Decomposers

A species that feeds or grows on dead plant and animal material. Also called a detritivore

Detritivores

A species that feeds or grows on dead plant and animal material. Also called a decomposer

Food chain

Specific feeding relationships between species at different trophic levels

Food web

A network of feeding relationships among species

Guild

A group of species at the same trophic level that use approximately the same environmental resources

Abiotic

Not derived from living things

Biotic

Related to living things

Evolution

Genetic changes over time in a population that sometimes can result in a new species

Keystone species

A species that has a disproportionate impact (relative to its numbers or biomass) on the organization of a biological community. Loss of a keystone species may have far-reaching consequences for the community

Trophic cascade

Major changes in vegetation and biodiversity resulting from the loss of a keystone species

Ecosystem engineers

Species that modify the physical structure of an ecosystem

Extinction cascade

A series of linked extinctions whereby the extinction of one species leads to the extinction of one or more other species

Keystone resources

Any resource in an ecosystem that is crucial to the survival of many species (Ex. watering hole)

Healthy ecosystem

Ecosystem in which processes are functioning normally, whether or not there are human influences

Stable ecosystems

Ecosystems that are able to remain in roughly the same compositional state despite human intervention or stochastic events such as unseasonable weather

Resistance

The ability of an ecosystem to remain in the same state even with ongoing disturbance

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Resilience

The ability of an ecosystem to return to its original state following disturbance

Bioblitz

A one-day event in which scientists and citizen scientists perform an intensive biological survey of a designated area in a short time with the goal of documenting all living species in that area

Endemic species

Species found in one place and nowhere else (Ex. the many lemur species found only on the island of Madagascar)

Option value

Value of biodiversity in providing possible future benefits for human society (such as new medicines)

Perverse subsidies

Government payments or other financial incentives to industries that result in environmentally destructive activities

Precautionary Principle

Principle stating that it may be better to avoid taking a particular action due to the possibility of causing unexpected harm

Private Goods

Value assigned to products, such as timber and animals, that are harvested and directly used by the people who harvest them. Also known as commodity value or private goods

Productive Use value

Value assigned to products that are sold in markets

Public goods

Nonconsumptive benefits that belong to society in general, without private ownership. Also known as indirect use values

Replacement cost approach

How much people would have to pay for an equivalent product if what they normally use is unavailable

Tragedy of the commons

The unregulated use of a public resource that results in its degradation

Use values

The direct and indirect values provided by some aspect of biodiversity

Acid rain

Rainwater that has become acidic due to air pollution

Biomagnification

Process whereby toxins become more concentrated in animals at higher levels in the food chain

Ecological footprint

The influence a group of people has on both the surrounding environment and locations across the globe as measured by global hectares per person

Edge effects

Altered environmental and biological conditions at the edges of a fragmented habitat