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Carrier's Constraint
Carrier's constraint is the observation that air-breathing vertebrates which have two lungs and flex their bodies sideways during locomotion find it very difficult to move and breathe at the same time, because the sideways flexing expands one lung and compresses the other, shunting stale air from lung to lung instead of expelling it completely to make room for fresh air. It was named by English paleontologist Richard Cowen for David R. Carrier, who wrote his observations on the problem in 1987. Consequences Most lizards move in short bursts, with long pauses for breath. Around the Late Triassic period, animals with Carrier's constraint were preyed on by bipedal species that evolved a more efficient stride. Solutions Workarounds Most snakes have only one lung, so Carrier's constraint does not apply. Monitor lizards increase their stamina by using bones and muscles in the throat and floor of the mouth to "gulp" air via gular pumping. Some other lizards, mainly agamids, use bipe ...
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Eublepharis Macularius 2009 G6
''Eublepharis'' is a genus of terrestrial geckos native to eastern and southwestern Asia. The genus was first described by the British zoologist John Edward Gray in 1827. The etymology of their name is 'eu' = good (=true) , 'blephar' = eyelid, and all have fully functional eyelids. Members of this genus are found in eastern and southwestern Asia. These geckos are sturdily built. Their tail is shorter than their snout–vent length, and their body is covered with numerous wart-like bumps. The toes do not have adhesive lamellae or membranes (''Eublepharis'' cannot climb like their other gecko cousins). Like all members of Eublepharidae, they are primarily nocturnal. Included in this group is the popular pet leopard gecko ''Eublepharis macularius''. Species of the genus ''Eublepharis'' The members of the ''Goniurosaurus kuroiwae'' superspecies were formerly considered members of the genus ''Eublepharis''. References External links *Eublepharis' in the Reptile Database The ...
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Agamid
Agamidae is a family of over 300 species of iguanian lizards indigenous to Africa, Asia, Australia, and a few in Southern Europe. Many species are commonly called dragons or dragon lizards. Overview Phylogenetically, they may be sister to the Iguanidae, and have a similar appearance. Agamids usually have well-developed, strong legs. Their tails cannot be shed and regenerated like those of geckos (and several other families such as skinks), though a certain amount of regeneration is observed in some. Many agamid species are capable of limited change of their colours to regulate their body temperature. In some species, males are more brightly coloured than females, and colours play a part in signaling and reproductive behaviours. Although agamids generally inhabit warm environments, ranging from hot deserts to tropical rainforests, at least one species, the mountain dragon, is found in cooler regions. They are particularly diverse in Australia. This group of lizards includes som ...
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Evolutionary Physiology
Evolutionary physiology is the study of the biological evolution of physiological structures and processes; that is, the manner in which the functional characteristics of individuals in a population of organisms have responded to natural selection across multiple generations during the history of the population. It is a sub-discipline of both physiology and evolutionary biology. Practitioners in the field come from a variety of backgrounds, including physiology, evolutionary biology, ecology, and genetics. Accordingly, the range of phenotypes studied by evolutionary physiologists is broad, including life history, behavior, whole-organism performance, functional morphology, biomechanics, anatomy, classical physiology, endocrinology, biochemistry, and molecular evolution. The field is closely related to comparative physiology and environmental physiology, and its findings are a major concern of evolutionary medicine. One definition that has been offered is "the study of the physio ...
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Limerick (poetry)
A limerick ( ) is a form of verse, usually humorous and frequently rude, in five-line, predominantly trimeter with a strict rhyme scheme of AABBA, in which the first, second and fifth line rhyme, while the third and fourth lines are shorter and share a different rhyme. The following example is a limerick of unknown origin: The form appeared in England in the early years of the 18th century. It was popularized by Edward Lear in the 19th century, although he did not use the term. Gershon Legman, who compiled the largest and most scholarly anthology, held that the true limerick as a folk form is always obscene, and cites similar opinions by Arnold Bennett and George Bernard Shaw, describing the clean limerick as a "periodic fad and object of magazine contests, rarely rising above mediocrity". From a folkloric point of view, the form is essentially transgressive; violation of taboo is part of its function. Form The standard form of a limerick is a stanza of five lines, with the ...
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Mammal
Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or hair, and three middle ear bones. These characteristics distinguish them from reptiles (including birds) from which they diverged in the Carboniferous, over 300 million years ago. Around 6,400 extant species of mammals have been described divided into 29 orders. The largest orders, in terms of number of species, are the rodents, bats, and Eulipotyphla (hedgehogs, moles, shrews, and others). The next three are the Primates (including humans, apes, monkeys, and others), the Artiodactyla ( cetaceans and even-toed ungulates), and the Carnivora (cats, dogs, seals, and others). In terms of cladistics, which reflects evolutionary history, mammals are the only living members of the Synapsida (synapsids); this clade, together with Saur ...
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Bird
Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweight skeleton. Birds live worldwide and range in size from the bee hummingbird to the ostrich. There are about ten thousand living species, more than half of which are passerine, or "perching" birds. Birds have whose development varies according to species; the only known groups without wings are the extinct moa and elephant birds. Wings, which are modified forelimbs, gave birds the ability to fly, although further evolution has led to the loss of flight in some birds, including ratites, penguins, and diverse endemic island species. The digestive and respiratory systems of birds are also uniquely adapted for flight. Some bird species of aquatic environments, particularly seabirds and some waterbirds, have further evolved for swimming. B ...
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University Of Utah
The University of Utah (U of U, UofU, or simply The U) is a public research university in Salt Lake City, Utah. It is the flagship institution of the Utah System of Higher Education. The university was established in 1850 as the University of Deseret () by the General Assembly of the provisional State of Deseret, making it Utah's oldest institution of higher education. It received its current name in 1892, four years before Utah attained statehood, and moved to its current location in 1900. As of Fall 2019, there were 24,485 undergraduate students and 8,333 graduate students, for an enrollment total of 32,818, making it the second largest public university in the state after Utah Valley University. Graduate studies include the S.J. Quinney College of Law and the School of Medicine, Utah's first medical school. It is a member of the Association of American Universities (AAU) and is classified among "R1: Doctoral Universities – Very high research activity". According to the ...
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Crocodilia
Crocodilia (or Crocodylia, both ) is an order of mostly large, predatory, semiaquatic reptiles, known as crocodilians. They first appeared 95 million years ago in the Late Cretaceous period ( Cenomanian stage) and are the closest living relatives of birds, as the two groups are the only known survivors of the Archosauria. Members of the order's total group, the clade Pseudosuchia, appeared about 250 million years ago in the Early Triassic period, and diversified during the Mesozoic era. The order Crocodilia includes the true crocodiles (family Crocodylidae), the alligators and caimans (family Alligatoridae), and the gharial and false gharial (family Gavialidae). Although the term 'crocodiles' is sometimes used to refer to all of these, crocodilians is a less ambiguous vernacular term for members of this group. Large, solidly built, lizard-like reptiles, crocodilians have long flattened snouts, laterally compressed tails, and eyes, ears, and nostrils at the top ...
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Bipedal Locomotion
Bipedalism is a form of terrestrial locomotion where an organism moves by means of its two rear limbs or legs. An animal or machine that usually moves in a bipedal manner is known as a biped , meaning 'two feet' (from Latin ''bis'' 'double' and ''pes'' 'foot'). Types of bipedal movement include walking, running, and hopping. Several groups of modern species are habitual bipeds whose normal method of locomotion is two-legged. In the Triassic period some groups of archosaurs (a group that includes crocodiles and dinosaurs) developed bipedalism; among the dinosaurs, all the early forms and many later groups were habitual or exclusive bipeds; the birds are members of a clade of exclusively bipedal dinosaurs, the theropods. Within mammals, habitual bipedalism has evolved multiple times, with the macropods, kangaroo rats and mice, springhare, hopping mice, pangolins and hominin apes (australopithecines, including humans) as well as various other extinct groups evolving the trait ...
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Natural History (magazine)
''Natural History'' is a natural history magazine published in the United States. The stated mission of the magazine is to promote public understanding and appreciation of nature and science. History Founded in 1900 by the American Museum of Natural History, ''Natural History'' was first titled ''The American Museum Journal''. In 2002, the magazine was purchased from the Museum by a new company, headed at the time by Charles Harris. As of 2013 the magazine is published in North Carolina by Howard Richman. There are 10 issues published annually. Since its founding, ''Natural History'' has chronicled the major expeditions and research findings by curators at the American Museum of Natural History and at other natural history museums and science centers. Stephen Jay Gould's column, "This View of Life," was a regular feature of the magazine from 1974 until he retired the column in 2001. Other regular columnists and contributing authors include Neil deGrasse Tyson, Jared Diamond, ...
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Vertebrates
Vertebrates () comprise all animal taxa within the subphylum Vertebrata () ( chordates with backbones), including all mammals, birds, reptiles, amphibians, and fish. Vertebrates represent the overwhelming majority of the phylum Chordata, with currently about 69,963 species described. Vertebrates comprise such groups as the following: * jawless fish, which include hagfish and lampreys * jawed vertebrates, which include: ** cartilaginous fish (sharks, rays, and ratfish) ** bony vertebrates, which include: *** ray-fins (the majority of living bony fish) *** lobe-fins, which include: **** coelacanths and lungfish **** tetrapods (limbed vertebrates) Extant vertebrates range in size from the frog species ''Paedophryne amauensis'', at as little as , to the blue whale, at up to . Vertebrates make up less than five percent of all described animal species; the rest are invertebrates, which lack vertebral columns. The vertebrates traditionally include the hagfish, which do no ...
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Gular Pumping
Buccal pumping is "breathing with one's cheeks": a method of ventilation used in respiration in which the animal moves the floor of its mouth in a rhythmic manner that is externally apparent.Brainerd, E. L. (1999). New perspectives on the evolution of lung ventilation mechanisms in vertebrates. Experimental Biology Online 4, 11-28. http://www.brown.edu/Departments/EEB/brainerd_lab/pdf/Brainerd-1999-EBO.pdf It is the sole means of inflating the lungs in amphibians. There are two methods of buccal pumping, defined by the number of movements of the floor of the mouth needed to complete both inspiration and expiration. Four stroke Four-stroke buccal pumping is used by some basal ray-finned fish and aquatic amphibians such as ''Xenopus'' and ''Amphiuma''. This method has several stages. These will be described for an animal starting with lungs in a deflated state: First, the glottis (opening to the lungs) is closed, and the nostrils are opened. The floor of the mouth is then depresse ...
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