Question Answer
habitat fragmentation break ecosystems into small parts, may be too small to support populations of some species (grizzly bears require large territories), to resolve, make wildlife reserves/parks larger and/or establish migration corridors
reestablishment of a community/habitat after it has been altered restoration
Reasons to protect endangered species may be useful to humans in the future (medicines, etc.), ecological value (disappearance of one will affect other species), intrinsic/moral value (has right to live)
common traits of endangered species long lived, low reproductive rate, high on food chain, economic value

natural process sped up by humans (mass extinctions = lots in a short period of time), causes typically habitat destruction, poaching, introduced species natural disaster extinction
endemic (naturally occur) in an ecosystem native species
species whose existence is critical to maintenance of ecosystem keystone species
species that serve as early warnings that an ecosystem is being damaged indicator species
species speciates into several others to fill vacant niches (ex. Darwin’s finches with different beak sizes on Galapagos Islands) adaptive radiation
Islands and species relationship? tend to have fewer species than mainland, number of species on an island depends upon its size and distance from mainland
when species in two different areas look alike convergent evolution
populations of the same species diverge into two new ones divergent evolution
two species arise from one, steps include geographic and then reproductive isolation speciation
initial establishment of communities in an area of bare rock primary succession
first species to appear in primary succession such as lichens, moss pioneer species
reestablishment of vegetation in an area following a disturbance secondary succession
final stage in ecological succession, stable, highest species diversity, only change back to earlier stage due to fire, severe storm, logging, etc. climax community
factors in environment which affect species survival and reproduction selective pressures
traits that better allow an organism to survive and reproduce adaptations
proposed by Charles Darwin, 3 conditions for evolution to occur by natural selection are variability for trait must exist in population, trait must me heritable, and trait must lead to differential reproductive success natural selection
theory regarding how populations change over time, refers to a change in population’s gene pool over time evolution