7/31/2019 3 Levels of Biodiversity
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3 Levels of Biodiversity
Species diversity
Species diversity is the effective number of different species
that are represented in a collection
of individuals (a dataset). The effective number of species
refers to the number of equally-
abundant species needed to obtain the same mean proportional
species abundance as that
observed in the dataset of interest (where all species may not
be equally abundant). Species
diversity consists of two components,species richnessandspecies
evenness. Species richness is
a simple count of species, whereas species evenness quantifies
how equal theabundancesof the
species are.[1][2][3]
Genetic diversity
Genetic Diversity, the level ofbiodiversity, refers to the total
number ofgeneticcharacteristics
in the genetic makeup of a species. It is distinguished
fromgenetic variability, which describes
the tendency of genetic characteristics to vary.
Genetic diversity serves as a way for populations to adapt to
changing environments. With more
variation, it is more likely that some individuals in a
population will possess variations of alleles
that are suited for the environment. Those individuals are more
likely to survive to produce
offspring bearing that allele. The population will continue for
more generations because of the
success of these individuals.
[1]
The academic field ofpopulation geneticsincludes several
hypotheses and theories regarding
genetic diversity. Theneutral theory of evolutionproposes that
diversity is the result of the
accumulation of neutral substitutions.Diversifying selectionis
the hypothesis that two
subpopulations of a species live in different environments that
select for differentallelesat a
particular locus. This may occur, for instance, if a species has
a large range relative to the
mobility of individuals within it.Frequency-dependent
selectionis the hypothesis that as alleles
become more common, they become more vulnerable. This in
host-pathogeninteractions, where
a high frequency of a defensive allele among the host means that
it is more likely that a pathogen
will spread if it is able to overcome that allele.
Ecosystem diversity
Ecosystem diversity refers to the diversity of a place at the
level ofecosystems. The term differs from
biodiversity, which refers to variation in species rather than
ecosystems. Ecosystem diversity can also
refer to the variety of ecosystems present in a biosphere, the
variety of species and ecological processes
that occur in different physical settings.
http://en.wikipedia.org/wiki/Species_richnesshttp://en.wikipedia.org/wiki/Species_richnesshttp://en.wikipedia.org/wiki/Species_richnesshttp://en.wikipedia.org/wiki/Species_evennesshttp://en.wikipedia.org/wiki/Species_evennesshttp://en.wikipedia.org/wiki/Species_evennesshttp://en.wikipedia.org/wiki/Abundance_%28ecology%29http://en.wikipedia.org/wiki/Abundance_%28ecology%29http://en.wikipedia.org/wiki/Abundance_%28ecology%29http://en.wikipedia.org/wiki/Species_diversity#cite_note-Hill1973-0http://en.wikipedia.org/wiki/Species_diversity#cite_note-Hill1973-0http://en.wikipedia.org/wiki/Species_diversity#cite_note-Tuomisto2010c-2http://en.wikipedia.org/wiki/Species_diversity#cite_note-Tuomisto2010c-2http://en.wikipedia.org/wiki/Biodiversityhttp://en.wikipedia.org/wiki/Biodiversityhttp://en.wikipedia.org/wiki/Biodiversityhttp://en.wikipedia.org/wiki/Geneticshttp://en.wikipedia.org/wiki/Geneticshttp://en.wikipedia.org/wiki/Geneticshttp://en.wikipedia.org/wiki/Genetic_variabilityhttp://en.wikipedia.org/wiki/Genetic_variabilityhttp://en.wikipedia.org/wiki/Genetic_variabilityhttp://en.wikipedia.org/wiki/Genetic_diversity#cite_note-U.S._Geological_Survey-0http://en.wikipedia.org/wiki/Genetic_diversity#cite_note-U.S._Geological_Survey-0http://en.wikipedia.org/wiki/Genetic_diversity#cite_note-U.S._Geological_Survey-0http://en.wikipedia.org/wiki/Population_geneticshttp://en.wikipedia.org/wiki/Population_geneticshttp://en.wikipedia.org/wiki/Population_geneticshttp://en.wikipedia.org/wiki/Neutral_theory_of_evolutionhttp://en.wikipedia.org/wiki/Neutral_theory_of_evolutionhttp://en.wikipedia.org/wiki/Neutral_theory_of_evolutionhttp://en.wikipedia.org/wiki/Disruptive_selectionhttp://en.wikipedia.org/wiki/Disruptive_selectionhttp://en.wikipedia.org/wiki/Disruptive_selectionhttp://en.wikipedia.org/wiki/Allelehttp://en.wikipedia.org/wiki/Allelehttp://en.wikipedia.org/wiki/Allelehttp://en.wikipedia.org/wiki/Frequency-dependent_selectionhttp://en.wikipedia.org/wiki/Frequency-dependent_selectionhttp://en.wikipedia.org/wiki/Frequency-dependent_selectionhttp://en.wikipedia.org/wiki/Pathogenhttp://en.wikipedia.org/wiki/Pathogenhttp://en.wikipedia.org/wiki/Pathogenhttp://en.wikipedia.org/wiki/Ecosystemhttp://en.wikipedia.org/wiki/Ecosystemhttp://en.wikipedia.org/wiki/Ecosystemhttp://en.wikipedia.org/wiki/Biodiversityhttp://en.wikipedia.org/wiki/Biodiversityhttp://en.wikipedia.org/wiki/Biodiversityhttp://en.wikipedia.org/wiki/Ecosystemhttp://en.wikipedia.org/wiki/Pathogenhttp://en.wikipedia.org/wiki/Frequency-dependent_selectionhttp://en.wikipedia.org/wiki/Allelehttp://en.wikipedia.org/wiki/Disruptive_selectionhttp://en.wikipedia.org/wiki/Neutral_theory_of_evolutionhttp://en.wikipedia.org/wiki/Population_geneticshttp://en.wikipedia.org/wiki/Genetic_diversity#cite_note-U.S._Geological_Survey-0http://en.wikipedia.org/wiki/Genetic_variabilityhttp://en.wikipedia.org/wiki/Geneticshttp://en.wikipedia.org/wiki/Biodiversityhttp://en.wikipedia.org/wiki/Species_diversity#cite_note-Tuomisto2010c-2http://en.wikipedia.org/wiki/Species_diversity#cite_note-Hill1973-0http://en.wikipedia.org/wiki/Species_diversity#cite_note-Hill1973-0http://en.wikipedia.org/wiki/Abundance_%28ecology%29http://en.wikipedia.org/wiki/Species_evennesshttp://en.wikipedia.org/wiki/Species_richness
