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Hydrochoerus Ballesterensis
The genus ''Hydrochoerus'' contains two living and two extinct species of rodents from South America, the Caribbean island of Grenada, California and Panama. Capybaras are the largest living rodents in the world. The genus name is derived from the Greek ὕδωρ (''hýdor'', water) plus χοίρος (''choíros'', pig). Characteristics Capybaras are semiaquatic, found in and near lakes, rivers, swamps, and flooded savanna. Their diets are dominated by grasses. Adults weigh up to . The gestation period is 130–150 days, with two to eight (most commonly four) young born to females. Behavior Capybaras are highly social, living in groups of up to 100 and communicating through a variety of vocalizations.Rowe and Honeycutt, 2002 Breeding is polygynous, with males forming harems. Phylogeny and taxonomy Molecular results have consistently suggested ''Hydrochoerus'' is most closely related to ''Kerodon'' (the rock cavies), and the two evolved from within the Caviidae. This led W ... [...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] |
Panama
Panama ( , ; es, link=no, Panamá ), officially the Republic of Panama ( es, República de Panamá), is a transcontinental country spanning the southern part of North America and the northern part of South America. It is bordered by Costa Rica to the west, Colombia to the southeast, the Caribbean Sea to the north, and the Pacific Ocean to the south. Its capital and largest city is Panama City, whose metropolitan area is home to nearly half the country's million people. Panama was inhabited by indigenous tribes before Spanish colonists arrived in the 16th century. It broke away from Spain in 1821 and joined the Republic of Gran Colombia, a union of Nueva Granada, Ecuador, and Venezuela. After Gran Colombia dissolved in 1831, Panama and Nueva Granada eventually became the Republic of Colombia. With the backing of the United States, Panama seceded from Colombia in 1903, allowing the construction of the Panama Canal to be completed by the United States Army Corps of En ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecular Phylogenetics And Evolution
''Molecular Phylogenetics and Evolution'' is a peer-reviewed scientific journal of evolutionary biology and phylogenetics. The journal is edited by E.A. Zimmer. Indexing The journal is indexed in: *EMBiology *Journal Citation Reports *Scopus Scopus is Elsevier's abstract and citation database launched in 2004. Scopus covers nearly 36,377 titles (22,794 active titles and 13,583 inactive titles) from approximately 11,678 publishers, of which 34,346 are peer-reviewed journals in top-l ... * Web of Science External links * Elsevier academic journals Evolutionary biology journals Phylogenetics Molecular biology Publications established in 1992 Monthly journals {{biology-journal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miocene
The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recent" because it has 18% fewer modern marine invertebrates than the Pliocene has. The Miocene is preceded by the Oligocene and is followed by the Pliocene. As Earth went from the Oligocene through the Miocene and into the Pliocene, the climate slowly cooled towards a series of ice ages. The Miocene boundaries are not marked by a single distinct global event but consist rather of regionally defined boundaries between the warmer Oligocene and the cooler Pliocene Epoch. During the Early Miocene, the Arabian Peninsula collided with Eurasia, severing the connection between the Mediterranean and Indian Ocean, and allowing a faunal interchange to occur between Eurasia and Africa, including the dispersal of proboscideans into Eurasia. During the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecular Clock
The molecular clock is a figurative term for a technique that uses the mutation rate of biomolecules to deduce the time in prehistory when two or more life forms diverged. The biomolecular data used for such calculations are usually nucleotide sequences for DNA, RNA, or amino acid sequences for proteins. The benchmarks for determining the mutation rate are often fossil or archaeological dates. The molecular clock was first tested in 1962 on the hemoglobin protein variants of various animals, and is commonly used in molecular evolution to estimate times of speciation or radiation. It is sometimes called a gene clock or an evolutionary clock. Early discovery and genetic equidistance The notion of the existence of a so-called "molecular clock" was first attributed to Émile Zuckerkandl and Linus Pauling who, in 1962, noticed that the number of amino acid differences in hemoglobin between different lineages changes roughly linearly with time, as estimated from fossil evidence. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrochoerinae
Hydrochoerinae is a subfamily of Caviidae, consisting of two living genera, ''Hydrochoerus'', the capybaras, and ''Kerodon'', the rock cavies. In addition, a number of extinct genera related to capybaras should also be placed in this subfamily. The taxonomy of Hydrochoerinae is confused because, until 2005, living capybaras and their extinct relatives were placed in their own family, Hydrochoeridae.McKenna, Malcolm C., and Bell, Susan K. 1997. ''Classification of Mammals Above the Species Level.'' Columbia University Press, New York, 631 pp. Recent molecular phylogenetic studies recognize a close relationship between ''Hydrochoerus'' and ''Kerodon'', supporting placement of both genera in a subfamily of Caviidae. Paleontological classifications have yet to incorporate this new taxonomy, and continue to use Hydrochoeridae for all capybaras, while using Hydrochoerinae for the living genus and its closest fossil relatives such as ''Neochoerus ''Neochoerus'' ("new hog") is an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caviidae
Caviidae, the cavy family, is composed of rodents native to South America and includes the domestic guinea pig, wild cavies, and the largest living rodent, the capybara. They are found across South America in open areas from moist savanna to thorn forests or scrub desert. This family of rodents has fewer members than most other rodent families, with 19 species in 6 genera in 3 subfamilies. Characteristics With the exception of the maras, which have a more rabbit-like appearance, caviids have short, heavy bodies and large heads. Most have no visible tails. They range in size from the smaller cavies at 22 cm in body length, and 300 grams in weight, up to the capybara, the largest of all rodents at 106 to 134 cm in length, and body weights of 35 to 66 kilograms. Even larger forms existed in the Pliocene, such as '' Phugatherium'', which was about the size of a tapir. They are herbivores, eating tough grasses or softer leaves, depending on species. The dental f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kerodon
The genus ''Kerodon'' (vernacular name Mocos; Rock Cavies) contains two species of South American rock cavies, related to capybaras and guinea pigs. They are found in semiarid regions of northeast Brazil known as the Caatinga. This area has a rocky terrain with large granite boulders that contain rifts and hollows where ''Kerodon'' spp. primarily live. Characteristics They are hystricomorph rodents, medium-sized, with rabbit-like bodies, a squirrel-like face, and heavily padded feet. Their nails are blunt on all digits except a small grooming claw on the outermost digit of the foot. Fully grown adults weigh around 1000 g or 31-35 oz, and range in length from 200 to 400 mm or 7.5 to 16 in. They forage for mostly leaves, grasses, seeds, and tree bark. They breed year round, usually having one to three litters per year and one to three young per pregnancy. Gestation last around 76 days and the young are weaned from the mother within 33 days. They reach sexual maturity at 133 days. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecular Phylogeny
Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to determine the processes by which diversity among species has been achieved. The result of a molecular phylogenetic analysis is expressed in a phylogenetic tree. Molecular phylogenetics is one aspect of molecular systematics, a broader term that also includes the use of molecular data in taxonomy and biogeography. Molecular phylogenetics and molecular evolution correlate. Molecular evolution is the process of selective changes (mutations) at a molecular level (genes, proteins, etc.) throughout various branches in the tree of life (evolution). Molecular phylogenetics makes inferences of the evolutionary relationships that arise due to molecular evolution and results in the construction of a phylogenetic tree. History The theoretical framew ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Harem (zoology)
A harem is an animal group consisting of one or two males, a number of females, and their offspring. The dominant male drives off other males and maintains the unity of the group. If present, the second male is subservient to the dominant male. As juvenile males grow, they leave the group and roam as solitary individuals or join bachelor herds. Females in the group may be inter-related. The dominant male mates with the females as they become sexually active and drives off competitors, until he is displaced by another male. In some species, incoming males that achieve dominant status may commit infanticide. For the male, the primary benefit of the harem system is obtaining exclusive access to a group of mature females. The females benefit from being in a stable social group and the associated benefits of grooming, predator avoidance and cooperative defense of territory. The disadvantages for the male are the energetic costs of gaining or defending a harem which may leave him with r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polygyny In Animals
Polygyny (; from Neo-Greek πολυγυνία, from πολύ- ''poly-'', "many", and γυνή ''gyne'', "woman" or "wife") is a mating system in which one male lives and mates with multiple females but each female only mates with a single male. Systems where several females mate with several males are defined either as promiscuity or polygynandry. Lek mating is frequently regarded as a form of polygyny, because one male mates with many females, but lek-based mating systems differ in that the male has no attachment to the females with whom he mates, and that mating females lack attachment to one another.Clutton-Brock T.H. (1989). ‘Review lecture: mammalian mating systems.' ''Proceedings of the Royal Society of London''. Series B, Biological Sciences 236: 339–372. Polygyny is typical of one-male, multi-female groupsBoyd, R., & Silk, J. B. (2009). How Humans Evolved (preferably the downloadable pdf version): WW Norton & Company, New York. and can be found in many species includi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Animal Communication
Animal communication is the transfer of information from one or a group of animals (sender or senders) to one or more other animals (receiver or receivers) that affects the current or future behavior of the receivers. Information may be sent intentionally, as in a courtship display, or unintentionally, as in the transfer of scent from predator to prey. Information may be transferred to an "audience" of several receivers. Animal communication is a rapidly growing area of study in disciplines including animal behavior, sociology, neurology and animal cognition. Many aspects of animal behavior, such as symbolic name use, emotional expression, learning and sexual behavior, are being understood in new ways. When the information from the sender changes the behavior of a receiver, the information is referred to as a "signal". Signalling theory predicts that for a signal to be maintained in the population, both the sender and receiver should usually receive some benefit from the interact ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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