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Strawberry Poison-dart Frog
The strawberry poison frog, strawberry poison-dart frog or blue jeans poison frog (''Oophaga pumilio'', formerly ''Dendrobates pumilio'') is a species of small poison dart frog found in Central America. It is common throughout its range, which extends from eastern central Nicaragua through Costa Rica and northwestern Panama. The species is often found in humid lowlands and premontane forest, but large populations are also found in disturbed areas such as plantations.Savage, J. M. 2002. The Amphibians and Reptiles of Costa Rica. University of Chicago Press, Chicago and London. The strawberry poison frog is perhaps most famous for its widespread variation in coloration, comprising approximately 15–30 color morphs, most of which are presumed to be true-breeding. ''O. pumilio'', while not the most poisonous of the dendrobatids, is the most toxic member of its genus. Diet The diet of ''O. pumilio'' causes the skin of the amphibian to become toxic in nature when certain subspec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eduard Oscar Schmidt
Eduard Oscar Schmidt (21 February 1823, in Torgau – 17 January 1886, in Kappelrodeck) was a German zoologist and phycologist. Biography He initially studied mathematics and science at Halle, then continued his education in Berlin, where he came under the influence of Christian Gottfried Ehrenberg and Johannes Peter Müller. In 1847 he received his habilitation at the University of Jena, becoming an associate professor during the following year. In 1855 was he appointed professor of zoology at the University of Cracow. Later he taught classes at the Universities of Graz (from 1857) and Strasbourg (from 1872). Schmidt was an early proponent of Darwinian evolutionary thought. He is remembered for his research of Porifera (sponges), particularly species from the Adriatic Sea. Schmidt also made contributions in the field of phycology. As far back as 1862 Oscar Schmidt showed that "cuttings" of sponges will attach themselves and grow. This idea was followed through in the exp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diurnality
Diurnality is a form of plant and ethology, animal behavior characterized by activity during daytime, with a period of sleeping or other inactivity at night. The common adjective used for daytime activity is "diurnal". The timing of activity by an animal depends on a variety of environmental factors such as the temperature, the ability to gather food by sight, the risk of predation, and the time of year. Diurnality is a cycle of activity within a 24-hour period; cyclic activities called circadian rhythms are endogenous cycles not dependent on external cues or environmental factors except for a zeitgeber. Animals active during twilight are crepuscular, those active during the night are nocturnal and animals active at sporadic times during both night and day are cathemerality, cathemeral. Plants that open their flowers during the daytime are described as diurnal, while those that bloom during nighttime are nocturnal. The timing of flower opening is often related to the time at which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aposematism
Aposematism is the advertising by an animal to potential predators that it is not worth attacking or eating. This unprofitability may consist of any defences which make the prey difficult to kill and eat, such as toxicity, venom, foul taste or smell, sharp spines, or aggressive nature. These advertising signals may take the form of conspicuous coloration, sounds, odours, or other perceivable characteristics. Aposematic signals are beneficial for both predator and prey, since both avoid potential harm. The term was coined in 1877 by Edward Bagnall Poulton for Alfred Russel Wallace's concept of warning coloration. Aposematism is exploited in Müllerian mimicry, where species with strong defences evolve to resemble one another. By mimicking similarly coloured species, the warning signal to predators is shared, causing them to learn more quickly at less of a cost. A genuine aposematic signal that a species actually possesses chemical or physical defences is not the only way to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetic Drift
Genetic drift, also known as allelic drift or the Wright effect, is the change in the frequency of an existing gene variant (allele) in a population due to random chance. Genetic drift may cause gene variants to disappear completely and thereby reduce genetic variation. It can also cause initially rare alleles to become much more frequent and even fixed. When few copies of an allele exist, the effect of genetic drift is more notable, and when many copies exist, the effect is less notable. In the middle of the 20th century, vigorous debates occurred over the relative importance of natural selection versus neutral processes, including genetic drift. Ronald Fisher, who explained natural selection using Mendelian genetics, held the view that genetic drift plays at most a minor role in evolution, and this remained the dominant view for several decades. In 1968, population geneticist Motoo Kimura rekindled the debate with his neutral theory of molecular evolution, which claims that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Russell Lande
Russell Scott Lande (born 1951) is an American evolutionary biologist and ecologist, and an International Chair Professor at Centre for Biodiversity Dynamics at the Norwegian University of Science and Technology (NTNU). He is a fellow of the Royal Society and a member of the United States National Academy of Sciences. Education and career He received his Ph.D. in 1976 from Harvard University where he was a student of Richard Lewontin, and completed his Postdoctoral work at the University of Wisconsin under James F. Crow. He then held positions at the University of Chicago, University of Oregon, University of California, San Diego, and Imperial College London. In 2016 he was employed as an International Chair Professor at the Norwegian University of Science and Technology (NTNU). Work Lande is best known for his early work extending quantitative genetics theory to the context of evolutionary biology in natural populations. In particular, he developed a stochastic theory for th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oophaga Sylvatica
''Oophaga sylvatica'', sometimes known as its Spanish name diablito, is a species of frog in the family Dendrobatidae found in Southwestern Colombia and Northwestern Ecuador. Its natural habitat is lowland and submontane rainforest; it can, however, survive in moderately degraded areas, at least in the more humid parts of its range. It is a very common frog in Colombia, but has disappeared from much of its Ecuadorian range. It is threatened by habitat loss (deforestation) and agricultural pollution and sometimes seen in the international pet trade. This species occurs in several color morphs. For example, the Bilsa Biological Station (operated by the Jatun Sacha Foundation) boasts three color morphs—red, yellow, and orange—within their 3000-ha protected area located within Ecuador's Mache and Chindul coastal mountain ranges. Description ''Oophaga sylvatica'' only displays sexual dimorphism in body size, as both males and females typically have a snout-vent length of 26 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polkadot Poison Frog
The polkadot poison frog (''Oophaga arborea'') is a species of frogs in the family Dendrobatidae endemic to Panama, where it is known as rana venenosa in Spanish. Its natural habitats are humid lowland and montane forests. It is threatened by habitat loss and is listed by the IUCN as being "critically endangered". Description The snout-to-vent length of the polkadot poison frog is . The hind limbs are short and the forelimbs relatively long with large hands. The fingers are unwebbed, the second one being longer than the first, and all but the first finger have flat discs of thickened skin. This frog has brown eyes and no teeth in its upper jaw. Males have a small vocal sac on the throat, and when not in use, this hangs in folds. The skin on the belly and inside the thighs is coarsely wrinkled. This frog is black or some shade of brown with roundish yellow spots, which often have a raised surface. The call made by the male is similar to that of closely related species but can be di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pliocene
The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58See the 2014 version of the ICS geologic time scale million years ago. It is the second and most recent epoch of the Neogene Period in the . The Pliocene follows the Epoch and is followed by the Epoch. Prior to the 2009 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monophyletic
In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic groups are typically characterised by shared derived characteristics ( synapomorphies), which distinguish organisms in the clade from other organisms. An equivalent term is holophyly. The word "mono-phyly" means "one-tribe" in Greek. Monophyly is contrasted with paraphyly and polyphyly as shown in the second diagram. A ''paraphyletic group'' consists of all of the descendants of a common ancestor minus one or more monophyletic groups. A '' polyphyletic group'' is characterized by convergent features or habits of scientific interest (for example, night-active primates, fruit trees, aquatic insects). The features by which a polyphyletic group is differentiated from others are not inherited from a common ancestor. These definitions have tak ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bromeliad
The Bromeliaceae (the bromeliads) are a family of monocot flowering plants of about 80 genera and 3700 known species, native mainly to the tropical Americas, with several species found in the American subtropics and one in tropical west Africa, ''Pitcairnia feliciana''. It is among the basal families within the Poales and is the only family within the order that has septal nectaries and inferior ovaries.Judd, Walter S. Plant systematics a phylogenetic approach. 3rd ed. Sunderland, MA: Sinauer Associates, Inc., 2007. These inferior ovaries characterize the Bromelioideae, a subfamily of the Bromeliaceae. The family includes both epiphytes, such as Spanish moss (''Tillandsia usneoides''), and terrestrial species, such as the pineapple (''Ananas comosus''). Many bromeliads are able to store water in a structure formed by their tightly overlapping leaf bases. However, the family is diverse enough to include the tank bromeliads, grey-leaved epiphyte ''Tillandsia'' species that gath ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cloaca
In animal anatomy, a cloaca ( ), plural cloacae ( or ), is the posterior orifice that serves as the only opening for the digestive, reproductive, and urinary tracts (if present) of many vertebrate animals. All amphibians, reptiles and birds, and a few mammals ( monotremes, tenrecs, golden moles, and marsupial moles), have this orifice, from which they excrete both urine and feces; this is in contrast to most placental mammals, which have two or three separate orifices for evacuation. Excretory openings with analogous purpose in some invertebrates are also sometimes referred to as cloacae. Mating through the cloaca is known as cloacal copulation, commonly referred to as cloacal kiss. The cloacal region is also often associated with a secretory organ, the cloacal gland, which has been implicated in the scent-marking behavior of some reptiles, marsupials, amphibians, and monotremes. Etymology The word is from the Latin verb ''cluo'', "(I) cleanse", thus the noun ''cloaca'', ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amplexus
Amplexus (Latin "embrace") is a type of mating behavior exhibited by some externally fertilizing species (chiefly amphibians and horseshoe crabs) in which a male grasps a female with his front legs as part of the mating process, and at the same time or with some time delay, he fertilizes the eggs, as they are released from the female's body. In amphibians, females may be grasped by the head, waist, or armpits, and the type of amplexus is characteristic of some taxonomic groups. Amplexus involves direct contact between male and female, distinguished from other forms of external fertilization, such as broadcast spawning, where sperm and eggs are freely shed into water without direct contact by individuals. In order for amplexus to be initiated, male frogs must first find a mate by attracting one through calls, typically in the evening. Once a male has successfully attracted a mate, the process of amplexus begins, while the unsuccessful males are forced to continue their search fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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