Chapter 3: Biodiversity

Biological wealth

Living things are responsible for the structure & maintenance of all ecosystems

Biodiversity

an area's sum total of all organisms; The diversity of species, their genes, populations, & communities

Biological evolution

genetic change in populations of organisms across generations; May be random, or directed by natural selection

Selection

the process by which traits that enhance survival and reproduction are passed on more frequently to future generations than those that do not

Adaptation

a trait (characteristic) that promotes reproductive success

Mutations

accidental changes in DNA that may be passed on to the next generation

Artificial selection

the process of selection conducted under human direction

Population

a group of individuals of a species that live in the same area

Species

a population or group of populations whose members share characteristics and can freely breed with one another and produce fertile offspring

Extinction

the disappearance of a species from Earth

Threatened

species numbers are nearing critical stage

Ecology

the study of interactions among organisms and their environment

Population ecology

investigates the quantitative dynamics of how individuals within a species interact

Community ecology

focuses on interactions among species

Ecosystem ecology

studies living and non-living components of systems to reveal patterns; Nutrient and energy flows

Habitat

the specific environment in which an organism lives

Habitat use

each organism thrives in certain habitats, but not in others

Habitat selection

the process by which organisms actively select habitats in which to live

Niche

an organism's use of resources and its functional role in a community

Specialists

species with narrow niches and very specific requirements

Generalists

species with broad niches that can use a wide array of habitats and resources

Population density

the number of individuals within a population per unit area

Limiting factors

physical, chemical, and biological characteristics that restrain population growth

Environmental resistance

all limiting factors taken together that stop exponential growth