apes unit 2

Species richness

Species richness

The number of species in a given area.

Species evenness

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

Phylogeny

The branching pattern of evolutionary relationships.

Evolution

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

Microevolution

Evolution below the species level.

Macroevolution

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

Gene

The physical location on the chromosomes within each cell of an organism.

Genotype

The complete set of genes in an individual.

Phenotype

The set of traits expressed by an individual.

Mutation

A random change in the genetic code produced by a mistake in the copying process.

Recombination

The genetic process by which one chromosome breaks off and attaches to another chromosome during reproductive cell division.

Evolution by artificial selection

The process in which humans determine which individuals 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.

Gene flow

The process by which individuals move from one population to another and thereby alter the genetic composition of both populations (gene migration).

Genetic drift

The change in the genetic composition of a population over time as a result of random mating (the change in frequency of an existing gene variant in the population due to RANDOM CHANCE).

Bottleneck effect

The reduction in the genetic diversity of a population caused by a reduction in its size.

Extinction

The death of the last member of a species.

Founder effect

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

Geographic isolation

The physical separation of a group of individuals from others of the same species.

Allopatric speciation

The process of speciation that occurs with geographic isolation (GEOGRAPHY ISOLATION).

Reproductive isolation

The result of two populations within a species evolving separately to the point that they can no longer interbreed and produce viable offspring.

Sympatric speciation

The evolution of one species into two, without geographic isolation (SAME geography).

Genetically modified organism (GMO)

An organism that is produced by copying genes from a species with a desirable trait and inserting them into another species.

Range of tolerance

The limits to the abiotic conditions.

Fundamental niche

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

Realized niche

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

Distribution

The areas of the world in which a species lives.

Niche generalists

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

Niche specialists

Species that are specialized to live in a specific habitat or to feed on a small group of species.

Mass extinction

A large extinction of species in a relatively short period of time.

Population

The individuals that belong to the same species and live in a given area at a particular time.

Community

All of the populations of organisms within a given area.

Population ecology

The study of factors that cause populations to increase or decrease.

Population size (N)

The total number of individuals within a defined area at a given time.

Population density

The number of individuals per unit area at a given time.

Population distribution

A description of how individuals are distributed with respect to one another.

Sex ratio

The ratio of males to females in a population.

Age structure

A description of how many individuals fit into particular age categories in a population.

Limiting resource

A resource that a population cannot live without and that occurs in lower quantities than the population would require to increase in size.

Density-dependent factor

A factor that influences an individual's probability of survival and reproduction in a manner that depends on the size of the population.

Carrying capacity (K)

The limit of how many individuals in a population the environment can sustain.

Density-independent factor

A factor that has the same effect on an individual's probability of survival and the amount of reproduction at any population size.

Population growth models

Mathematical equations that can be used to predict population size at any moment in time.

Population growth rate

The number of offspring an individual can produce in a given time period, minus the deaths of the individuals or its offspring during the same period.

Intrinsic growth rate (r)

The maximum potential for growth of a population under ideal conditions with unlimited resources.

Exponential growth model

A growth model that estimates a population's future size after a period of time, based on the intrinsic growth rate and the number of reproducing individuals currently in the population.

J-shaped curve

The curve of the exponential growth model when graphed.

Logistic growth model

A growth model that describes a population whose growth is initially exponential but slows as the population approaches the carrying capacity of the environment.

S-shaped curve

The shape of the logistic growth model when graphed.

Overshoot

When a population becomes larger than the environment's carrying capacity.

Die-off

A rapid decline in a population due to death.

K-selected species

A species with a low intrinsic growth rate that causes the population to increase slowly until it reaches carrying capacity.

r-selected species

Species that have a high intrinsic growth rate, which often leads to population overshoots and die-offs.

Survivorship curve

A graph that represents the pattern of survival over time in a population.

Type I survivorship curve

A pattern of survival over time in which there is high survival throughout most of the life span, but then individuals start to die in large numbers as they approach old age.

Type II survivorship curve

A pattern of survival over time in which there is a relatively constant decline in survivorship throughout most of the life span.

Type III survivorship curve

A pattern of survival over time in which there is low survivorship early in life, with few individuals reaching adulthood.

Corridor

Strips of natural habitat that connect populations.

Metapopulation

A group of spatially distinct populations that are connected by occasional movements of individuals between them.

Inbreeding depression

When individuals with similar genotypes breed with each other and produce offspring that have an impaired ability to survive and reproduce.

Community ecology

The study of interactions between species.

Symbiotic relationship

A relationship between two species that live in close association with each other.

Competition

The struggle of individuals to obtain a shared limiting resource.

Competitive exclusion principle

The principle stating that two species competing for the same limiting resource cannot coexist.

Resource partitioning

When two species divide a resource based on differences in their behavior or morphology.

Predation

interaction in which one animals typically kills and consumes another animal

Parasitoid

specialized type of predator that lays eggs inside other organism

Parasitism

interaction in which one organism lives on or in another organism

Pathogen

parasite that causes a disease in its host

herbivory

interaction in which an animal consumers a producer

mutualism

interaction between two species that increases the chances of survival or reproduction for both species

commensalism

relationship between species in which ones species benefits and the other species is neither benefited nor harmed

Keystone species

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

Ecosystem engineer

keystone species that creates or maintains habitat for other species

threatened species

according to the International Union for Conservation of Nature, species that have a high risk of extinction in the future

near threatened species

species that are very likely to become threatened in the future

least concern species

species that are widespread and abundant

intrinsic value

value independent of any benefit to humans (value even tho not value to human)

instrumental value

worth as an instrument or a tool that can be used to accomplish a goal

provision

a good that humans can use directly

native species

species that live in their historical range, typically where they have lived for thousands or millions of years

exotic species

a species living outside its historical range

invasive species

species that spreads rapidly across large areas and causes harm

lacey act

a US act that prohibits interstate shipping of all illegally harvested plants and animals

Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES)

1973 treaty formed to control the international trade of threatened plants and animals

red list

list of worldwide threatened species

endangered species

species that is in danger of extinction within foreseeable future

threatened species

any species that is likely to become an endangered species within foreseeable future

convention on biological diversity

an international treaty to help protect biodiversity

edge habitat

habitat that occurs where two different communities come together, typically forming an abrupt transition1

biosphere reserve

protected area consisting of zones that vary in the amount of permissible human impact