Evolution
5.1
5.1
The process by which traitsthat improve an organism’s chances for survival and repro-duction are passed on more frequently to future generationsthan those that do not.
Natural Selection
A relationship in which two or more species benefit
mutualism
A species that has strong or wide reaching impact on a community.
keystone species
A disturbance, such as a fire, logging, or farming,dramatically alters an existing community but does not destroy all livingthings or all organic matter in the soil.
secondary sucession
Animals gathering around a water hole in a drought-prone area and establishing hierarchies of access to the water is an example of competition.
True.
Biological evolution that occurs by chance.
genetic drift
The use of resources and its functional role in a community.
niche.
A rank in a feeding hierarchy.
(Primary producers always make up a community’s first level. Primary, secondary, and tertiary consumers make up the second, third, and fourth levels. In theory, a community can have any number of levels)
trophic level
A nonnative organism that spreads widely in a community causing disturbance and a major problem in many parts of the world.
invasive species
In a mass extinction, the rate of extinction exceeds
the rate of background extinction.
The process by which new species are generated.
speciation.
A long-lasting and physically close relationship in which at least one organism benefits.
symbiosis
The process by which organismsuse oxygen to release the chemical energy of sugars such asglucose, releasing carbon dioxide and water as a byproduct.
Cellular Respiration
A community is built essentially from scratch. It takes place after a bare expanse of rock, sand, or sediment is exposed for the first time. This can occur when glaciers retreat, lakes dry up, or volcanic lava or ash spreads across the landscape
primary sucession
In the history of the world, how many mass extinctions have occurred?
5
The disappearance of a species from Earth.
extinction
The process bywhich two species evolve in response to changes in each other. A changein one species, therefore, is usually followed by a change in the other
Coevolution
The total amount of living tissue it contains
biomass
A community experiences a somewhat predictable series of changes over time.
A niche restricted by competition is a
realized niche.
A heritable trait that increases an individual’s fitness
adaptation.
When species compete, they tend to divide resources. Many types of birds—including the wood peckers, creeper, and nuthatch shown here—feed on insects from tree trunks. By each specializing in particular insects on particular parts of the tree, the birds minimize competition.
Resource Partitioning
A visual map of feeding relationships and energy flow, showing the many paths by which energy and nutrients pass among organisms as they consume one another.
food web
Species that colonizethe newly exposed land first
pioneer species
Two species of finch live in the same environment. Over time, one develops a larger beak to consume larger seeds, while the other develops a narrow beak to consume more delicate seeds. This is an example of
Character Displacement