Chapter 5: Biodiversity, Species Interactions, and Population Control

Ecological succession

The normal, gradual change in species composition in a given geographic area.

Genetic drift

A change in the genetic composition of a population over time as a result of random mating.

Population Dynamics

The analysis of the factors that affect the increase, stability, and decrease of populations over time.

Carrying Capacity (k)

The maximum population of a given species that a habitat can sustain indefinitely.

Interspecific Competition

Occurs when two or more species interact to gain access to the same limited resources

Predation

Occurs when a member of one species (predator) feeds directly on all or part of a member of another species (prey)

Symbiosis

close, long-term association 2 or more species, 3 types

Parasitism

occurs when one organism (the parasite) feeds on another organism (the host), usually living on or in the host

Mutualism

is an interaction that benefits both species by providing

Commensalism

is an interaction that benefits one species but has little, if any, effect on the other

Competition

Two or more animals competing for the same resources

Competitive Exclusion Principle

No two species can occupy the same niche indefinitely in a habitat where there is not enough of a particular resource to meet the needs of both species

Intraspecific Competition

A competition between individuals from the same species

Interspecific Competition

Competition between members of two different species

Resource Partitioning

occurs when species competing for similar scarce resources evolve specialized traits that allow them to use shared resources at different times, in different ways, or in different places

Physical protection

shells, thick bark, spines

Camouflage

shapes and colors

Chemical warfare

poisons, irritating (stinging), foul-smelling or bad tasting (can be poisonous)

Mimicry

when a non-poisonous species looks like (mimics) a species that is poisonous

Coevolution

when populations of two different species interact over a long period of time, changes in the gene pool of one species can lead to changes in the gene pool of the other

Ecological succession

The normal, gradual change in species composition in a given geographic area

Primary Ecological Succession

The gradual establishment of biotic communities in lifeless areas where there is no soil in a terrestrial ecosystem or no bottom sediment in an aquatic system

Secondary Ecological Succession

Occurs were communities or ecosystems have been disturbed, removed, or destroyed, but retain some soil or bottom sediments

Population Dynamics

The analysis of the factors that affect the increase, stability, and decrease of populations over time

Age Structure

A model that predicts the population growth rate by a shape

Population density

The number of individuals in a given geographic area

Biotic potential

The maximum reproductive rate of an organism

Environmental resistance

The sum of all factors that limit the growth of a population

Carrying Capacity (k)

The maximum population of a given species that a habitat can sustain indefinitely

Logistic Growth

When a population grows rapidly, reaches carrying capacity, and stabilizes

r-selected species

Have short life spans

K-selected species

Reproduce later in life

Founder effect

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

Demographic Bottleneck

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

Genetic drift

A change in the genetic composition of a population over time as a result of random mating

Interspecific Competition

Occurs when two or more species interact to gain access to the same limited resources.

Predation

Occurs when a member of one species (predator) feeds directly on all or part of a member of another species (prey).

Parasitism

occurs when one organism (the parasite) feeds on another organism (the host), usually living on or in the host.

Mutualism

is an interaction that benefits both species by providing

Commensalism

is an interaction that benefits one species but has little, if any, effect on the other.

Competitive Exclusion Principle

No two species can occupy the same niche indefinitely in a habitat where there is not enough of a particular resource to meet the needs of both species.

Intraspecific Competition

A competition between individuals from the same species

Interspecific Competition

Competition between members of two different species

Resource Partitioning

occurs when species competing for similar scarce resources evolve specialized traits that allow them to use shared resources at different times, in different ways, or in different places.

Coevolution

when populations of two different species interact over a long period of time, changes in the gene pool of one species can lead to changes in the gene pool of the other

Primary Ecological Succession

The gradual establishment of biotic communities in lifeless areas where there is no soil in a terrestrial ecosystem or no bottom sediment in an aquatic system

Secondary Ecological Succession

Occurs were communities or ecosystems have been disturbed, removed, or destroyed, but retain some soil or bottom sediments

Population Dynamics

The analysis of the factors that affect the increase, stability, and decrease of populations over time.

Age Structure

A model that predicts the population growth rate by a shape

Biotic potential

The maximum reproductive rate of an organism

Environmental resistance

The sum of all factors that limit the growth of a population

Carrying Capacity (k)

The maximum population of a given species that a habitat can sustain indefinitely

Logistic Growth

When a population grows rapidly, reaches carrying capacity, and stabilizes

r-selected species

Have short life spans. Have many, usually small offspring and do not provide much parental care/protection

K-selected species

Reproduce later in life. Have smaller numbers of offspring with longer life spans. Typically develop inside their mothers and are born fairly large. After birth, they mature slowly and are protected by one or both parents

Founder effect

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

Demographic Bottleneck

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

Genetic drift

A change in the genetic composition of a population over time as a result of random mating

Population change equation

(births + immigration) – (deaths + emigration)