Genetic, species, and ecosystem diversity

Objective: Explain genetic diversity and species diversity, distinguish their meanings, and apply them to a described case.

Genetic diversity: Genetic diversity is variation in hereditary information within or among populations. Species diversity: Species diversity reflects both the number of species and their relative abundances. Biodiversity measures answer different questions. Species richness counts kinds of species, while evenness describes their relative representation. Genetic differences can affect responses to disease or environmental change within one species. Ecosystem diversity adds a landscape scale. Surveys depend on area, sampling effort, identification, and timing, so comparisons should use compatible methods. A numerical diversity measure is helpful but cannot alone establish every aspect of ecosystem condition. Application: Individuals in one crop population carry different inherited variants. This most directly illustrates genetic diversity. A survey compares species counts and how evenly individuals are distributed. This most directly illustrates species diversity.

Objective: Explain ecosystem diversity and species richness, distinguish their meanings, and apply them to a described case.

Ecosystem diversity: Ecosystem diversity is the variety of ecosystems or habitat types in a region. Species richness: Species richness is the number of species in a defined area or sample. Biodiversity measures answer different questions. Species richness counts kinds of species, while evenness describes their relative representation. Genetic differences can affect responses to disease or environmental change within one species. Ecosystem diversity adds a landscape scale. Surveys depend on area, sampling effort, identification, and timing, so comparisons should use compatible methods. A numerical diversity measure is helpful but cannot alone establish every aspect of ecosystem condition. Application: A landscape contains wetlands, grasslands, and forests. This most directly illustrates ecosystem diversity. One sampled site contains more distinct species than another. This most directly illustrates species richness.

Objective: Explain species evenness and endemic species, distinguish their meanings, and apply them to a described case.

Species evenness: Species evenness describes how evenly individuals are distributed among species. Endemic species: An endemic species is native to a restricted geographical region. Biodiversity measures answer different questions. Species richness counts kinds of species, while evenness describes their relative representation. Genetic differences can affect responses to disease or environmental change within one species. Ecosystem diversity adds a landscape scale. Surveys depend on area, sampling effort, identification, and timing, so comparisons should use compatible methods. A numerical diversity measure is helpful but cannot alone establish every aspect of ecosystem condition. Application: A community has similar numbers of individuals in its different species. This most directly illustrates species evenness. A species naturally occurs on only one island group. This most directly illustrates endemic species.