Search results
Results from the WOW.Com Content Network
Biologists most often define biodiversity as the "totality of genes, species and ecosystems of a region". [8] [9] An advantage of this definition is that it presents a unified view of the traditional types of biological variety previously identified: taxonomic diversity (usually measured at the species diversity level) [10]
Biodiversity is usually plotted as taxonomic richness of a geographic area, with some reference to a temporal scale. Whittaker [9] described three common metrics used to measure species-level biodiversity, encompassing attention to species richness or species evenness: Species richness - the simplest of the indices available. Simpson index
This type of dataset is typical in biodiversity studies. Observe how more than half the biodiversity (as measured by species count) is due to singletons. For real datasets, the species abundances are binned into logarithmic categories, usually using base 2, which gives bins of abundance 0–1, abundance 1–2, abundance 2–4, abundance 4–8, etc.
Relative species abundance is a component of biodiversity and is a measure of how common or rare a species is relative to other species in a defined location or community. [1] Relative abundance is the percent composition of an organism of a particular kind relative to the total number of organisms in the area.
Using computer simulations, Colwell and Hurtt (1994) and Willing and Lyons (1998) first pointed out that if species’ latitudinal ranges were randomly shuffled within the geometric constraints of a bounded biogeographical domain (e.g. the continents of the New World, for terrestrial species), species' ranges would tend to overlap more toward the center of the domain than towards its limits ...
Varieties of maize in the office of the Russian plant geneticist Nikolai Vavilov. A study conducted by the National Science Foundation in 2007 found that genetic diversity (within-species diversity) and biodiversity are dependent upon each other — i.e. that diversity within a species is necessary to maintain diversity among species, and vice versa.
The official logo of the TAKS test. Mainly based on the TAAS test's logo. The Texas Assessment of Knowledge and Skills (TAKS) was the fourth Texas state standardized test previously used in grade 3-8 and grade 9-11 to assess students' attainment of reading, writing, math, science, and social studies skills required under Texas education standards. [1]
Phylogenetic signal is a concept widely used in different ecological and evolutionary studies. [7]Among many questions that can be answered using a concept of phylogenetic signal, the most common ones are: [1]