Fauna of Ireland bear mtDNA. The closest surviving brown bear is Ursus arctos middendorffi in Alaska. Only one land reptile is native to the country, the viviparous lizard. It is common in national parks, particularly in the Wicklow Mountains. Slowworms are common in parts of The Burren area in County Clare, but they are not a native species and were probably introduced in the 1970s. Five marine turtle species appear regularly off the west coast, the leatherback, green, hawksbill, loggerhead, and Kemp's ridley, but they very rarely come ashore. Legend attributes the absence of snakes in Ireland to Saint Patrick, who is said
History of manifolds and varieties History of manifolds and varieties The study of manifolds combines many important areas of mathematics: it generalizes concepts such as curves and surfaces as well as ideas from linear algebra and topology. Certain special classes of manifolds also have additional algebraic structure; they may behave like groups, for instance. In that case, they are called Lie Groups. Alternatively, they may be described by polynomial equations, in which case they are called algebraic varieties, and if they additionally carry a group structure, they are called algebraic groups. The term "manifold" comes from German "Mannigfaltigkeit," by Riemann. In English, "manifold" refers to