On the number of species on Earth and in the ocean
The innovative analytical method plots data from higher taxonomic levels to predict the number of species. Below there is an example using the kingdom Animalia as a case study
The description of a new species requires its classification within the Linnaean system of classification adopted some 250 years ago. This is a hierarchical system in which lower taxonomic groups belong to higher ones. For instance, a specific species is grouped with other species of similar characteristics within a given genus, which, in turn, is grouped with other genera of similar characteristics within a given family, which is then grouped with other families of similar characteristics within a specific order and so on. In this hierarchical system there are more groups at lower taxonomic levels than at higher ones and while the later ones are almost fully discovered, the earlier ones (i.e. species) remain for the most part to be found. The pattern that has been discovered suggest that the better known number of higher taxonomic groups predicts the less well known number of lower groups, including the number of entities at the level of species.