BIOL 370 Study Guide - Quiz Guide: Diversity Index, Beta Diversity, Gamma Diversity
2 Apr 2019
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Document Summary
Current extinction rate is estimated at 100 1000 times the background rate. Speciation may be slowing because much of the earth"s surface is taken over for human use and no longer supports evolving biological communities. Fewer habitats and populations for evolution to happen in. Get down to the last members of a genus or family, we are losing ancient lineages. This is not balanced by the appearance of new species that are closely related to existing species. Evenness = relative abundance of species e. g. , shannon diversity index; highest diversity = communities with large numbers of species that are equally abundant, lowest = few or many species of unequal abundances. Alpha diversity = number of species in a designated area. Gamma diversity = applied to large geographic scales. i. e. number of species in a large region or continent. = rate of change of species composition along an environmental or geographic gradient.
