Chapter 12 vocab first half

Local extinction
occurs when a species disappears from a part of its range but persists elsewhere
Ecological extinction
when so few members of a species are left that they are unable to carry out their role in an ecosystem
Biological extinction
species no longer found anywhere on earth; forever
Endangered species
a species whose numbers are so small that the species is at risk of extinction
Threatened species
a species that could become endangered in the near future
Instrumental value
the worth that something has because of its use
Intrinsic value
value of an organism, species, ecosystem, or the earth's biodiversity based on its existence, regardless of whether it has any usefulness to us
habitat destruction, invasive species, population, pollution, overharvesting (factors endangering species)