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Ensatina
The ensatina (''Ensatina eschscholtzii'') is a species complex of plethodontid (lungless) salamanders found in coniferous forests, oak woodland and chaparralMonterey Ensatina San Diego Field Station, Viewed: April 24, 2005, Last updated: March 05, 2003 from , through Washington, |
Ensatina Eschscholtzii E
The ensatina (''Ensatina eschscholtzii'') is a species complex of plethodontid (lungless) salamanders found in coniferous forests, oak woodland and chaparralMonterey Ensatina San Diego Field Station, Viewed: April 24, 2005, Last updated: March 05, 2003 from , through , |
Ring Species
In biology, a ring species is a connected series of neighbouring populations, each of which interbreeds with closely sited related populations, but for which there exist at least two "end populations" in the series, which are too distantly related to interbreed, though there is a potential gene flow between each "linked" population and the next. Such non-breeding, though genetically connected, "end populations" may co-exist in the same region (sympatry) thus closing a "ring". The German term , meaning a circle of races, is also used. Ring species represent speciation and have been cited as evidence of common descent, evidence of evolution. They illustrate what happens over time as populations genetically diverge, specifically because they represent, in living populations, what normally happens over time between long-deceased ancestor populations and living populations, in which the intermediates have become extinct. The evolutionary biologist Richard Dawkins remarks that ring spec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
The Ancestor's Tale
''The Ancestor's Tale: A Pilgrimage to the Dawn of Life'' is a 2004 science book by Richard Dawkins and Yan Wong that delves into the topic of evolution. The book adopts a unique approach, retracing the path of humans in reverse chronological order through evolutionary history. Along the way, it introduces readers to various species, referred to as humanity's cousins, as they converge on shared common ancestors. Drawing on scientific principles and research, "The Ancestor's Tale" offers an accessible and thought-provoking exploration of life's origins and the intricate relationships that connect all living beings. Synopsis The book follows a path backwards in time through evolution and meets different groupings of organisms. In this backward chronology, the ancestors of any set of species must eventually meet at a particular moment. The last common ancestor is the one that they all share which the authors call a "concestor". The oldest concestor, LUCA, short for Last Universal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Salamander
Salamanders are a group of amphibians typically characterized by their lizard-like appearance, with slender bodies, blunt snouts, short limbs projecting at right angles to the body, and the presence of a tail in both larvae and adults. All ten extant salamander families are grouped together under the order Urodela, the sole surviving order from the group Caudata. ''Urodela'' is a scientific Latin term based on the Ancient Greek : ourà dēlē "conspicuous tail". ''Caudata'' is the Latin for "tailed ones", from : "tail". Salamander diversity is highest in eastern North America, especially in the Appalachian Mountains; most species are found in the Holarctic realm, with some species present in the Neotropical realm. Salamanders never have more than four toes on their front legs and five on their rear legs, but some species have fewer digits and others lack hind limbs. Their permeable skin usually makes them reliant on habitats in or near water or other cool, damp places. So ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Plethodontid
Plethodontidae, or lungless salamanders, are a family of salamanders. With over 500 species, lungless salamanders are by far the largest family of salamanders in terms of their diversity. Most species are native to the Western Hemisphere, from British Columbia to Brazil. Only two extant genera occur in the Eastern Hemisphere: ''Speleomantes'' (native to Sardinia and mainland Europe south of the Alps) and '' Karsenia'' (native to South Korea). Biology Adult lungless salamanders have four limbs, with four toes on the fore limbs, and usually with five on the hind limbs. Within many species, mating and reproduction occur solely on land. Accordingly, many species also lack an aquatic larval stage, a phenomenon known as direct development in which the offspring hatch as fully-formed, miniature adults. Direct development is correlated with changes in the developmental characteristics of plethodontids compared to other families of salamanders including increases in egg size and duratio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Complex (taxonomy)
In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each other, further blurring any distinctions. Terms that are sometimes used synonymously but have more precise meanings are cryptic species for two or more species hidden under one species name, sibling species for two (or more) species that are each other's closest relative, and species flock for a group of closely related species that live in the same habitat. As informal taxonomic ranks, species group, species aggregate, macrospecies, and superspecies are also in use. Two or more taxa that were once considered conspecific (of the same species) may later be subdivided into infraspecific taxa (taxa within a species, such as plant varieties), which may be a complex ranking but it is not a species complex. In most cases, a species complex is a mon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Central Valley (California)
The Central Valley is a broad, elongated, flat valley that dominates the interior of California, United States. It is wide and runs approximately from north-northwest to south-southeast, inland from and parallel to the Pacific coast. It covers approximately , about 11% of California's land area. The valley is bounded by the California Coast Ranges, Coast Ranges to the west and the Sierra Nevada to the east. The Central Valley is a region known for its agricultural productivity. It provides a large share of the food produced in California, which provides more than half of the fruits, vegetables, and nuts grown in the United States. More than of the valley are irrigated via reservoirs and canals. The valley hosts many cities, including the state capital Sacramento, California, Sacramento, as well as Redding, California, Redding, Chico, California, Chico, Yuba City, California, Yuba City, Woodland, California, Woodland, Davis, California, Davis, Stockton, California, Stockton, M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Horseshoe
A horseshoe is a product designed to protect a horse hoof from wear. Shoes are attached on the palmar surface (ground side) of the hooves, usually nailed through the insensitive hoof wall that is anatomically akin to the human toenail, although much larger and thicker. However, there are also cases where shoes are glued. Horseshoes are available in a wide variety of materials and styles, developed for different types of horses and for the work they do. The most common materials are steel and aluminium, but specialized shoes may include use of rubber, plastic, magnesium, titanium, or copper.Price, Steven D. (ed.) ''The Whole Horse Catalog: Revised and Updated'' New York:Fireside 1998 , pp. 84–87. Steel tends to be preferred in sports in which a strong, long-wearing shoe is needed, such as polo, eventing, show jumping, and western riding events. Aluminium shoes are lighter, making them common in horse racing where a lighter shoe is desired, and often facilitate certain ty ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
John Edward Gray
John Edward Gray (12 February 1800 – 7 March 1875) was a British zoologist. He was the elder brother of zoologist George Robert Gray and son of the pharmacologist and botanist Samuel Frederick Gray (1766–1828). The same is used for a zoological name. Gray was keeper of zoology at the British Museum in London from 1840 until Christmas 1874, before the natural history holdings were split off to the Natural History Museum. He published several catalogues of the museum collections that included comprehensive discussions of animal groups and descriptions of new species. He improved the zoological collections to make them amongst the best in the world. Biography Gray was born in Walsall, but his family soon moved to London, where Gray studied medicine. He assisted his father in writing ''The Natural Arrangement of British Plants'' (1821). After being blackballed by the Linnean Society of London, Gray shifted his interest from botany to zoology. He began his zoological ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
