|
Atrato River
The Atrato River () is a river of northwestern Colombia. It rises in the slopes of the Western Cordillera and flows almost due north to the Gulf of Urabá (or Gulf of Darién), where it forms a large, swampy delta. Its course crosses the Chocó Department, forming that department's border with neighboring Antioquia in two places. Its total length is about , and it is navigable as far as Quibdó (400 km / 250 mi), the capital of the department. Watershed of the Atrato River The river’s total length is about , and it is navigable as far as Quibdó (400 km / 250 mi), the capital of the department. The basin occupies an area of and has an average annual precipitation of >5,000 mm/year that reaches up to 12,000 mm/year in the upper basin. Flowing through a narrow valley between the Cordillera and coastal range, it has only short tributaries, the principal ones being the Truandó, the Sucio, and the Murrí rivers. The gold and platinum mines of Choc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colombia
Colombia (, ; ), officially the Republic of Colombia, is a country in South America with insular regions in North America—near Nicaragua's Caribbean coast—as well as in the Pacific Ocean. The Colombian mainland is bordered by the Caribbean Sea to the north, Venezuela to the east and northeast, Brazil to the southeast, Ecuador and Peru to the south and southwest, the Pacific Ocean to the west, and Panama to the northwest. Colombia is divided into 32 departments and the Capital District of Bogotá, the country's largest city. It covers an area of 1,141,748 square kilometers (440,831 sq mi), and has a population of 52 million. Colombia's cultural heritage—including language, religion, cuisine, and art—reflects its history as a Spanish colony, fusing cultural elements brought by immigration from Europe and the Middle East, with those brought by enslaved Africans, as well as with those of the various Amerindian civilizations that predate colonization. S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Auriferous
The mineral pyrite (), or iron pyrite, also known as fool's gold, is an iron sulfide with the chemical formula Fe S2 (iron (II) disulfide). Pyrite is the most abundant sulfide mineral. Pyrite's metallic luster and pale brass-yellow hue give it a superficial resemblance to gold, hence the well-known nickname of ''fool's gold''. The color has also led to the nicknames ''brass'', ''brazzle'', and ''Brazil'', primarily used to refer to pyrite found in coal. The name ''pyrite'' is derived from the Greek (), 'stone or mineral which strikes fire', in turn from (), 'fire'. In ancient Roman times, this name was applied to several types of stone that would create sparks when struck against steel; Pliny the Elder described one of them as being brassy, almost certainly a reference to what we now call pyrite. By Georgius Agricola's time, , the term had become a generic term for all of the sulfide minerals. Pyrite is usually found associated with other sulfides or oxides in quartz v ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
William Kennish
William Kennish (1799 – March 19, 1862) was an engineer, inventor, explorer, scientist, and poet, known primarily for inventions developed while he served in the British Royal Navy (1821–1841). They ranged from improvements for artillery to navigation and steering devices. After retiring from the Navy, Kennish worked as a schoolteacher on the Isle of Man. But in 1849, he migrated to the United States for more opportunities. He began surveying gold lands in Colombia, South America, for firms based in New York City. In 1855 he completed a report on a potential river aqueduct or canal across the northwest isthmus of present-day Colombia, using the Atrato River and emptying into Bahia Humboldt, Chocó and the Pacific Ocean. That year Congress approved a joint military expedition of a US Navy and Army party to explore this, and Kennish acted as their guide. He later died in New York. Life Kennish was born in the Parish of Maughold, on the Isle of Man, in a cottage at Cornaa on t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
San Juan River (Colombia)
The San Juan River () is an important river of Colombia that flows into the Pacific Ocean through the Chocó Department. It is approximately and drains a watershed of . The river drains into a large delta that covers nearly . The average discharge of the Rio San Juan is 2,054.67 m³/s. Geography The river begins on Cerro Caramanta in the West Andes. The delta is due north of Bahía Málaga and Buenaventura. The mouth of the river has extensive stands of mangroves, part of the Esmeraldas-Pacific Colombia mangroves ecoregion. Hydrometry Monthly average flow of San Juan River ( m³/second) measured at Penitas stationData from 25 years Colors= id:lightgrey value:gray(0.8) id:darkgrey value:gray(0.3) id:sfondo value:rgb(1,1,1) id:barra value:rgb(0.6,0.8,0.9) ImageSize = width:600 height:280 PlotArea = left:40 bottom:40 top:20 right:20 DateFormat = x.y Period = from:0 till:3000 TimeAxis = orientation:vertical AlignBars = justify ScaleMajor = gridcolor:lig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
White-footed Tamarin
The white-footed tamarin (''Saguinus leucopus'') is a tamarin species endemic to Colombia. It is a silvery brown colour with pale streaks and russet underparts, and is very similar in appearance to the cotton-top tamarin, from which it is separated by the Atrato River. It is thought that the two species diverged during the Pleistocene, at a time when a sea occupied the area between their present ranges. This tamarin is an arboreal species, living in small family groups in the canopy. Females give birth to one to three young after a gestation period of about 140 days. This species has a relatively small range and is under threat from destruction and fragmentation of the forest in which it lives and the International Union for Conservation of Nature has assessed its conservation status as "vulnerable". Taxonomy and phylogeny Some authorities, such as Thorington (1976), posit that ''S. leucopus'' is very closely related to the cotton-top tamarin, ''Saguinus oedipus''. Other analy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cotton-top Tamarin
The cotton-top tamarin (''Saguinus oedipus'') is a small New World monkey weighing less than . This New World monkey can live up to 24 years, but most of them die by 13 years. One of the smallest primates, the cotton-top tamarin is easily recognized by the long, white sagittal crest extending from its forehead to its shoulders. The species is found in tropical forest edges and secondary forests in northwestern Colombia, where it is arboreal and diurnal. Its diet includes insects and plant exudates, and it is an important seed disperser in the tropical ecosystem. The cotton-top tamarin displays a wide variety of social behaviors. In particular, groups form a clear dominance hierarchy where only dominant pairs breed. The female normally gives birth to twins and uses pheromones to prevent other females in the group from breeding. These tamarins have been extensively studied for their high level of cooperative care, as well as altruistic and spiteful behaviors. Communication betwe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Philip Hershkovitz
Philip Hershkovitz (12 October 1909 – 15 February 1997) was an American mammalogy, mammalogist. Born in Pittsburgh, he attended the Universities of Pittsburgh and Michigan and lived in South America collecting mammals. In 1947, he was appointed a curator at the Field Museum of Natural History in Chicago and he continued to work there until his death. He has published much on the mammals of the Neotropics, particularly primates and rodents, and described almost 70 new species and subspecies of mammals. About a dozen species have been named after him. Life Early life Philip Hershkovitz was born 12 October 1909 in Pittsburgh to parents Aba and Bertha (Halpern) Hershkovitz. He was the second child and only son among four siblings. He reported that his father died when he was nine years old. After graduating from Schenley High School in 1927, he attended the University of Pittsburgh from 1929 to 1931, majoring in zoology, before transferring to the University of Michigan at Ann Arb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allopatric Speciation
Allopatric speciation () – also referred to as geographic speciation, vicariant speciation, or its earlier name the dumbbell model – is a mode of speciation that occurs when biological populations become geographically isolated from each other to an extent that prevents or interferes with gene flow. Various geographic changes can arise such as the movement of continents, and the formation of mountains, islands, bodies of water, or glaciers. Human activity such as agriculture or developments can also change the distribution of species populations. These factors can substantially alter a region's geography, resulting in the separation of a species population into isolated subpopulations. The vicariant populations then undergo genetic changes as they become subjected to different selective pressures, experience genetic drift, and accumulate different mutations in the separated populations' gene pools. The barriers prevent the exchange of genetic information betwe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetic Divergence
Genetic divergence is the process in which two or more populations of an ancestral species accumulate independent genetic changes ( mutations) through time, often leading to reproductive isolation and continued mutation even after the populations have become reproductively isolated for some period of time, as there isn’t genetic exchange anymore. In some cases, subpopulations living in ecologically distinct peripheral environments can exhibit genetic divergence from the remainder of a population, especially where the range of a population is very large (see parapatric speciation). The genetic differences among divergent populations can involve silent mutations (that have no effect on the phenotype) or give rise to significant morphological and/or physiological changes. Genetic divergence will always accompany reproductive isolation, either due to novel adaptations via selection and/or due to genetic drift, and is the principal mechanism underlying speciation. On a molecular ge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magdalena River
The Magdalena River ( es, Río Magdalena, ; less commonly ) is the main river of Colombia, flowing northward about through the western half of the country. It takes its name from the biblical figure Mary Magdalene. It is navigable through much of its lower reaches, in spite of the shifting sand bars at the mouth of its delta, as far as Honda, at the downstream base of its rapids. It flows through the Magdalena River Valley. Its drainage basin covers a surface of , which is 24% of the country's area and where 66% of its population lives. Course The Magdalena River is the largest river system of the northern Andes, with a length of 1,612 km. Its headwaters are in the south of Colombia, where the Andean subranges Cordillera Central and Cordillera Oriental separate, in Huila Department. The river runs east then north in a great valley between the two cordilleras. It reaches the coastal plain at about nine degrees north, then runs west for about , then north again, reaching ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cauca River
The Cauca River () is a river in Colombia that lies between the Occidental and Central cordilleras. From its headwaters in southwestern Colombia near the city of Popayán, it joins the Magdalena River near Magangue in Bolivar Department, and the combined river eventually flows out into the Caribbean Sea. It has a length of to its junction with the Magdalena, for a total length of . from origin to seamouth. The river is under the supervision of the ''Cauca Regional Corporation'' and the ''Cauca Valley Regional Autonomous Corporation'', and is navigable for above its junction with the Magdalena. File:Rio cauca popayan.JPG File:Salvajina.jpg File:Río Cauca. Puente Anacaro (3). Cartago - Ansermanuevo, Valle, Colombia.JPG File:Río Cauca.JPG File:Puentes en La Pintada 01.jpg File:Puente de Occidente.JPG File:El río Cauca.jpg Environmental issues On November 18, 2007, Colombian newspaper '' El Tiempo'' reported that the river was receiving an average of 500 tons of residual w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleistocene
The Pleistocene ( , often referred to as the ''Ice age'') is the geological epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed in 2009 by the International Union of Geological Sciences, the cutoff of the Pleistocene and the preceding Pliocene was regarded as being 1.806 million years Before Present (BP). Publications from earlier years may use either definition of the period. The end of the Pleistocene corresponds with the end of the last glacial period and also with the end of the Paleolithic age used in archaeology. The name is a combination of Ancient Greek grc, label=none, πλεῖστος, pleīstos, most and grc, label=none, καινός, kainós (latinized as ), 'new'. At the end of the preceding Pliocene, the previously isolated North and South American continents were joined by the Isthmus of Panama, causing a faunal interchange between the two reg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.svg "Click for more on -> Atrato River")
