APES Types of Species

ecological niche

each specie's distinct role played in the ecosystems where it is found; pattern of living

fossils

mineralized or petrified replicas of skeletons, bones, teeth, shells, leaves, and seeds, or impressions of such items found in rocks

reproductive isolation

mutation and change by natural selection operate independently in gene pools of geographically isolated populations. If the process continues long enough, members of the geographically and reproductively isolated populations may become so different in genetic makeup that they cannot produce live, fertile offspring if they are to be rejoined

species richness

number of different species a community contains

species diversity

number of different species a community contains combined with the relative abundance of individuals within each of those species

geographic isolation

occurs when different groups of the same population of a species become physically isolated from one another for long periods (physical barrier in way or when few individuals are carried to a new area by wind or flowing water)

species evenness

relative abundance of individuals within each of the species in a community

natural selection

second step in the process of biological evolution genes mutate, individuals are selected, and populations evolve that are better adapted to survive and reproduce under existing environmental condidtions

mass extinction

significant rise in extinction rates above the background level

endemic species

species that are found in only one area; especially vulnerable to extinction

keystone species

species that have a large effect on the types and abundances of other species in an ecosystem

generalist species

species that have broad niches; can live in many different places, eat a variety of foods, and often tolerate a wide range of environmental conditions

specialist species

species that have narrow niches; can live in only one type of habitat, use one or few types of food, and tolerate a narrow range of climatic and other environmental condition

nonnative species

species that migrate into or are deliberately or accidentally introduced into an ecosystem also called invasive, alien, or exotic species

foundation species

species that play a major role in shaping communities by creating and enhancing their habitats in ways that benefit other species

indicator species

species that provide early warnings of damage to a community or an ecosystem

eubacteria, archaebacteria, protists, plants, fungi, animals

the six specific groups of species

native species

those species that normally live and thrive in a particular ecosystem

extinction

when an entire species ceases to exist

background extinction

when species disappear at a low rate

speciation

when two species arise from one from natural selection for sexually reproducing species, a new species is formed when some members of a population have evolved to the point where they can no longer breed with other members to produce fertile offspring