adaptation
a trait that helps an organism survive and reproduce
adaptive radiation
process by which a single species or small group of species evolves into several different forms that live in different ways; rapid growth in the diversity of a group of organisms
artificial selection
selection by humans for breeding of useful traits from the natural variation among different organisms
climate
Overall weather in an area over a long period of time
coevolution
process by which two species evolve in response to changes in each other
competition
the struggle between organisms to survive in a habitat with limited resources
niche
organism's role, or job, in its habitat
evolution
the process by which species gradually change over time
extinction
disappearance of a species from all parts of its geographical range
fossils
preserved remains of ancient organisms
gene flow
exchange of genes between populations
genetic drift
The gradual changes in gene frequencies in a population due to random events
mutation
change in a DNA sequence that affects genetic information
Fundemental niche
All the resources a species is capable of using
generalist species
Species 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. Examples are flies, cockroaches, mice, rats, and human beings. Compare specialist species.
geographic isolation
separation of populations as a result of geographic change or migration to geographically isolated places
habitat
Place where an Organism lives
macro evolution
evolution on a large scale, this leads to the formation of new species
micro evolution
changes in genes over time
mass extinction
event in which many types of living things become extinct at the same time
natural selection
process by which individuals that are better suited to their environment survive and reproduce most successfully; also called survival of the fittest
specialist species
Species with a narrow ecological niche. They may be able to live in only one type of habitat, tolerate only a narrow range of climatic and other environmental conditions, or use only one type or a few types of food.
reproductive isolation
separation of species that prevents them from interbreeding and producing fertile offspring
speciation
formation of new species
succulent plants
plants that survive in dry climates by having no leaves, thus reducing the loss of scarce water
broadleaf evergreen
tall trees with big leaves that remain green all year
broadleaf deciduous plants
plants such as oak and maple trees that survive drought and cold by shedding their leaves and becoming dormant
coniferous evergreen plants
Cone-bearing plants (such as spruces, pines, and firs) that keep some of their narrow, pointed leaves (needles) all year.
desert
an arid region with little or no vegetation
epiphyte
plant that is not rooted in soil but instead grows directly on the body of another plant
forest
an ecosystem in which many trees grow
grassland
biome characterized by fertile soils with a thick cover of grasses
permafrost
layer of permanently frozen subsoil in the tundra
prarie
a large area of level or rolling land with grass and few or no trees
theory of island biogeography
The number of species found on an island is determined by a balance between two factors: the immigration rate (of species new to the island) from other inhabited areas and the extinction rate (of species established on the island). The model predicts that
native species
species that have naturally evolved in an area
non native species
An introduced, alien, exotic, non-indigenous, or non-native specie is a species living outside its native distributional range, which has arrived there by human activity, either deliberate or accidental.
invasive species
species that enter new ecosystems and multiply, harming native species and their habitats
indicator species
species that serve as early warnings that an ecosystem is being damaged, ex trout
Keystone species
a species that influences the survival of many other species in an ecosystem
resource partitioning
in a biological community various populations sharing environmental resources through specialization thereby reducing direct competition
parasitism
one organism lives on or inside another organism and harms it
mutualism
a relationship between two species in which both species benefit
commensalism
symbiotic relationship in which one member of the association benefits and the other is neither helped nor harmed
interspecific competition
Competition between members of different species
intraspecific competition
in a community competition for resources among members of the same species
primary succession
an ecological succession that begins in a an area where no biotic community previously existed
secondary succession
succession on a site where an existing community has been disrupted
pioneer species
first species to populate an area during primary succession
facilitation
During succession, one species prepares the way for the next (and may even be necessary for the occurrence of the next)
inhibition
early species inhibit colonization by others, later species established only when early species disturbed
intermediate disturbance hypothesis
The concept that moderate levels of disturbance can foster greater species diversity than low or high levels of disturbance.
precautionary principle
A guiding principle in making decisions about the environment, cautioning to consider carefully the potential consequences of actions
resource partitioning
in a biological community various populations sharing environmental resources through specialization thereby reducing direct competition