Gray foxThe gray fox (Urocyon cinereoargenteus), or grey fox, is an omnivorous mammal of the family Canidae, widespread throughout North America and Central America. This species and its only congener, the diminutive island fox (Urocyon littoralis) of the California Channel Islands, are the only living members of the genus Urocyon, which is considered to be genetically basal to all other living canids. Its species name cinereoargenteus means "ashen silver".
VasodilationVasodilation, also known as vasorelaxation, is the widening of blood vessels. It results from relaxation of smooth muscle cells within the vessel walls, in particular in the large veins, large arteries, and smaller arterioles. The process is the opposite of vasoconstriction, which is the narrowing of blood vessels. When blood vessels dilate, the flow of blood is increased due to a decrease in vascular resistance and increase in cardiac output. Therefore, dilation of arterial blood vessels (mainly the arterioles) decreases blood pressure.
Mammal classificationMammalia is a class of animal within the phylum Chordata. Mammal classification has been through several iterations since Carl Linnaeus initially defined the class. No classification system is universally accepted; McKenna & Bell (1997) and Wilson & Reader (2005) provide useful recent compendiums. Many earlier ideas from Linnaeus et al. have been completely abandoned by modern taxonomists, among these are the idea that bats are related to birds or that humans represent a group outside of other living things.
Transmutation of speciesTransmutation of species and transformism are unproven 18th and 19th-century evolutionary ideas about the change of one species into another that preceded Charles Darwin's theory of natural selection. The French Transformisme was a term used by Jean Baptiste Lamarck in 1809 for his theory, and other 18th and 19th century proponents of pre-Darwinian evolutionary ideas included Denis Diderot, Étienne Geoffroy Saint-Hilaire, Erasmus Darwin, Robert Grant, and Robert Chambers, the anonymous author of the book Vestiges of the Natural History of Creation.
