Genus

More generally, the genus of a graph is the minimum genus of a two-dimensional surface into which the graph may be embedded; planar graphs have genus zero and nonplanar toroidal graphs have genus one.

The genus counts the number of holes in the manifold: the sphere has genus 0, the one-holed torus genus 1, etc. Non-compact surfaces Non-compact surfaces are more difficult to classify.

A Cephalogale-like species gave rise to the genus Ursavus during the early Oligocene (30–28 Mya); this genus proliferated into many species in Asia and is ancestral to all living bears.

Agaricus deserticola is a secotioid species of Agaricus (the genus of common cultivated mushrooms) which at one time was placed in the genus Secotium.

As the difference is potential within the genus; that is, an animal may or may not be rational, the difference is not identical to, and may be distinct from, the genus.

Biology In the taxonomical structure " genus → species ", a species is described as sui generis if its genus was created to classify it (i.

Classes of intensional definitions main A genus–differentia definition is a type of intensional definition that takes a large category (the genus) and narrows it down to a smaller category by a distinguishing characteristic (i.e. the differentia).

Confusion between the two pathogens' life-cycles led him to briefly recognize his genus Schizotrypanum, but following the description of Pneumocystis by others as an independent genus, Chagas returned to the use of the name Trypanosoma cruzi.

Cultural references Field guides and other technical resources Some of the better known books on the genus A number of field guides and other semi-technical books on the genus have been published.

Cumuliform clouds forming in the lower level were given the genus name cumulus from the Latin word for heap, citation and low stratiform clouds the genus name stratus from the Latin word for sheet or layer.

Furthermore, the living brown hyena and its closest extinct relatives are not included in the genus Pachycrocuta, but in the genus Hyaena.

Genus Australopithecus main The Australopithecus genus evolved in eastern Africa around 4 million years ago before spreading throughout the continent and eventually becoming extinct 2 million years ago.

However, in technical discourse and in American usage, the term "weasel" can refer to any member of the genus, or to the genus as a whole.

However, there have been no confirmed sightings of the marozi since the 1930s. citation A pumapard is a hybrid animal resulting from a mating between a leopard and a puma (a member of the genus Puma, not the genus Panthera).

In this terminology, planar graphs have graph genus 0, since the plane (and the sphere) are surfaces of genus 0. See " graph embedding " for other related topics.

It has sometimes been placed in the genus Diopecephalus because Harry Govier Seeley based this genus partly on the P. longicollum material.

Most hammerhead species are placed in the genus Sphyrna while the winghead shark is placed in its own genus, Eusphyra.

Phylogeny and Taxonomic Revision of the endemic Malagasy genus Ptychochromis (Teleostei: Cichlidae), with the description of five new species and a diagnosis for Katria, new genus.

Plants may be hybridized with different species within the same genus; hybridization between different genus may also be possible but more difficult.

Secotioid genus Nivatogastrium corresponds to agaric genus Pholiota and provides a vivid example of the phenomenon.