Andes

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Andes
Aerial photo of a portion of the Andes between Argentina and Chile
Highest point
Peak	Aconcagua (Las Heras Department, Mendoza, Argentina)
Elevation	6,962 m (22,841 ft)
Coordinates	32°39′10″S 70°0′40″WCoordinates: 32°39′10″S 70°0′40″W
Dimensions
Length	7,000 km (4,300 mi)
Width	500 km (310 mi)
Naming
Native name	Quechua: Anti(s/kuna)
Geography
Composite satellite image of the southern Andes
Countries	List[show]

The Andes is the longest continental mountain range in the world. It is a continual range of highlands along the western coast of South America. This range is about 7,000 km (4,300 mi) long, about 200 km (120 mi) to 700 km (430 mi) wide (widest between 18° south and 20° south latitude), and of an average height of about 4,000 m (13,000 ft). The Andes extend from north to south through seven South American countries: Venezuela, Colombia, Ecuador, Peru, Bolivia, Chile, and Argentina.

Along its length, the Andes is split into several ranges, which are separated by intermediate depressions. The Andes is the location of several high plateaux – some of which host major cities such as Quito, Bogotá, Arequipa, Medellín, Sucre, Mérida, and La Paz. The Altiplano plateau is the world's second-highest following the Tibetan plateau. These ranges are in turn grouped into three major divisions based on climate: the Tropical Andes, the Dry Andes, and the Wet Andes.

The Andes is the world's highest mountain range outside of Asia. The highest peak, Mount Aconcagua, rises to an elevation of about 6,962 m (22,841 ft) above sea level. The peak of Chimborazo in the Ecuadorean Andes is farther from Earth's center than any other location on Earth's surface, due to the equatorial bulge resulting from Earth's rotation. The world's highest volcanoes are in the Andes, including Ojos del Salado on the Chile-Argentina border which rises to 6,893 m (22,615 ft). Over 50 other Andean volcanoes rise above 6,000 m (19,685 ft). The peak of Alpamayo in the Andes of Peru rises to an elevation of 5,947 m (19,511 ft).

Name

The etymology of the word Andes has been debated. The major consensus is that it derives from the Quechua word anti which means "east"^[1] as in Antisuyu (Quechua for "east region"),^[1] one of the four regions of the Inca Empire. Derivation from the Spanish andén (in the sense of cultivation terrace) has also been proposed, yet considered very unlikely.

Geography

The Andes can be divided into three sections:

1. The Southern Andes (south of Llullaillaco) in Argentina and Chile;
2. The Central Andes in Ecuador, Peru and Bolivia
3. The Northern Andes (north of the Nudo de Pasto) in Venezuela and Colombia which consist of three parallel ranges, the western, central, and eastern ranges. (The cordillera occidental, central, and oriental.)

In the northern part of the Andes, the isolated Sierra Nevada de Santa Marta range is often considered to be part of the Andes. The term cordillera comes from the Spanish word "cuerda", meaning "rope".
The Andes range is about 200 km (124 mi) wide throughout its length, except in the Bolivian flexure where it is about 640 kilometres (398 mi) wide. The Leeward Antilles islands Aruba, Bonaire, and Curaçao, which lie in the Caribbean Sea off the coast of Venezuela, were thought to represent the submerged peaks of the extreme northern edge of the Andes range, but ongoing geological studies indicate that such a simplification does not do justice to the complex tectonic boundary between the South American and Caribbean plates.^[2]

Geology

The Andes are a Mesozoic–Tertiary orogenic belt of mountains along the Pacific Ring of Fire, a zone of volcanic activity that encompasses the Pacific rim of the Americas as well as the Asia-Pacific region. The Andes are the result of plate tectonics processes, caused by the subduction of oceanic crust beneath the South American plate. The main cause of the rise of the Andes is the compression of western rim of the South American Plate due to the subduction of the Nazca Plate and the Antarctic Plate. To the east, the Andes range is bounded by several sedimentary basins such as Orinoco, Amazon Basin, Madre de Dios and Gran Chaco which separates the Andes from the ancient cratons in eastern South America. In the south the Andes shares a long boundary with the former Patagonia Terrane. To the west, the Andes end at the Pacific Ocean, although the Peru-Chile trench can be considered its ultimate western limit. From a geographical approach the Andes are considered to have their western boundaries marked by the appearance of coastal lowlands and a less rugged topography.

Orogeny

The western rim of the South American Plate has been the place of several pre-Andean orogenies since at least the period of the late Proterozoic and early Paleozoic when several terranes and microcontinents collided and amalgamated with the ancient cratons of eastern South America, by then the South American part of Gondwana.

The formation of the modern Andes began with the events of the Triassic when Pangea began to break up and several rifts developed. It continued through the Jurassic Period. It was during the Cretaceous Period that the Andes began to take its present form, by the uplifting, faulting and folding of sedimentary and metamorphic rocks of the ancient cratons to the east. The rise of the Andes has not been constant and different regions have had different degrees of tectonic stress, uplift, and erosion.

Tectonic forces above the subduction zone along the entire west coast of South America where the Nazca Plate and a part of the Antarctic Plate are sliding beneath the South American Plate continue to produce an ongoing orogenic event resulting in minor to major earthquakes and volcanic eruptions to this day. In the extreme south a major transform fault separates Tierra del Fuego from the small Scotia Plate. Across the 1,000 km (620 mi) wide Drake Passage lie the mountains of the Antarctic Peninsula south of the Scotia Plate which appear to be a continuation of the Andes chain.^{[citation needed]}

Volcanism

Rift valley near Quilotoa, Ecuador.

Astronaut photograph with the high plains of the Andes Mountains in the foreground, with a line of young volcanoes facing the much lower Atacama Desert.

The Andes range has many active volcanoes, which are distributed in four volcanic zones separated by areas of inactivity. The Andean volcanism is a result of subduction of the Nazca Plate and Antarctic Plate underneath the South American Plate. The belt is subdivided into four main volcanic zones that are separated from each other by volcanic gaps. The volcanoes of the belt are diverse in terms of activity style, products and morphology. While some differences can be explained by which volcanic zone a volcano belongs to, there are significant differences inside volcanic zones and even between neighbouring volcanoes. Despite being a type location for calc-alkalic and subduction volcanism, the Andean Volcanic Belt has a large range of volcano-tectonic settings, such as rift systems and extensional zones, transpersonal faults, subduction of mid-ocean ridges and seamount chains apart from a large range of crustal thicknesses and magma ascent paths, and different amount of crustal assimilations.

Ore deposits and evaporites

The Andes mountains host large ore and salt deposits and some of its eastern fold and thrust belt acts as traps for commercially exploitable amounts of hydrocarbons. In the forelands of the Atacama desert some of the largest porphyry copper mineralizations occurs making Chile and Peru the first and second largest exporters of copper in the world. Porphyry copper in the western slopes of the Andes has been generated by hydrothermal fluids (mostly water) during the cooling of plutons or volcanic systems. The porphyry mineralization further benefited from the dry climate that let them largely out of the disturbing actions of meteoric water. The dry climate in the central western Andes have also led to the creation of extensive saltpeter deposits which were extensively mined until the invention of synthetic nitrates. Yet another result of the dry climate are the salars of Atacama and Uyuni, the first one being the largest source of lithium today and the second the world’s largest reserve of the element. Early Mesozoic and Neogene plutonism in Bolivia's Cordillera Central created the Bolivian tin belt as well as the famous, now depleted, deposits of Cerro Rico de Potosí.

Climate and hydrology

Central Andes

Bolivian Andes

The climate in the Andes varies greatly depending on latitude, altitude, and proximity to the sea. Temperature, atmospheric pressure and humidity decrease in higher elevations. The southern section is rainy and cool, the central Andes are dry. The northern Andes are typically rainy and warm, with an average temperature of 18 °C (64 °F) in Colombia. The climate is known to change drastically in rather short distances. Rainforests exist just miles away from the snow covered peak Cotopaxi. The mountains have a large effect on the temperatures of nearby areas. The snow line depends on the location. It is at between 4,500 and 4,800 m (14,800–15,800 ft) in the tropical Ecuadorian, Colombian, Venezuelan, and northern Peruvian Andes, rising to 4,800–5,200 m (15,800–17,060 ft) in the drier mountains of southern Peru south to northern Chile south to about 30°S, then descending to 4,500 m (14,760 ft) on Aconcagua at 32°S, 2,000 m (6,600 ft) at 40°S, 500 m (1,640 ft) at 50°S, and only 300 m (980 ft) in Tierra del Fuego at 55°S; from 50°S, several of the larger glaciers descend to sea level.^[3]

The Andes of Chile and Argentina can be divided in two climatic and glaciological zones; the Dry Andes and the Wet Andes. Since the Dry Andes extends from the latitudes of Atacama Desert to the area of Maule River, precipitation is more sporadic and there are strong temperature oscillations. The line of equilibrium may shift drastically over short periods of time, leaving a whole glacier in the ablation area or in the accumulation area.

In the high Andes of central Chile and Mendoza Province rock glaciers are larger and more common than glaciers; this is due to the high exposure to solar radiation.^[4]

Though precipitation increases with the height, there are semiarid conditions in the nearly 7000 m towering highest mountains of the Andes. This dry steppe climate is considered to be typically of the subtropic position at 32-34° S. Therefore in the valley bottoms do not grow woods but only dwarf scrub. The largest glaciers, as e.g. the Plomo glacier and the Horcones glaciers do not even reach 10 km in length and have an only insignificant ice thickness. At glacial times, however, c. 20 000 years ago, the glaciers were over ten times longer. On the east side of this section of the Mendozina Andes they flowed down to 2060 m and on the west side to c. 1220 m asl.^[5][6] The massifs of Cerro Aconcagua (6962 m), Cerro Tupungato (6550 m) and Nevado Juncal (6110 m) are deca-kilometres away from each other and were connected by a joint ice stream network. Its dendritic glacier arms, i.e. components of valley glaciers, were up to 112.5 km long, over 1020, i.e. 1250 m thick and overspanned a vertical distance of 5150 altitude metres. The climatic glacier snowline (ELA) was lowered from currently 4600 m to 3200 m at glacial times.^{[5][7][8][9][10][11][12][13][14]}

Flora

The Andean region cuts across several natural and floristic regions due to its extension from Caribbean Venezuela to cold, windy and wet Cape Horn passing through the hyperarid Atacama Desert. Rainforests used to encircle much of the northern Andes but are now greatly diminished, especially in the Chocó and inter-Andean valleys of Colombia. As a direct opposite of the humid Andean slopes are the relatively dry Andean slopes in most of western Peru, Chile and Argentina. Along with several Interandean Valles, they are typically dominated by deciduous woodland, shrub and xeric vegetation, reaching the extreme in the slopes near the virtually lifeless Atacama Desert.
About 30,000 species of vascular plants live in the Andes with roughly half being endemic to the region, surpassing the diversity of any other hotspot.^[15] The small tree Cinchona pubescens, a source of quinine which is used to treat malaria, is found widely in the Andes as far south as Bolivia. Other important crops that originated from the Andes are tobacco and potatoes. The high-altitude Polylepis forests and woodlands are found in the Andean areas of Colombia, Ecuador, Peru, Bolivia and Chile.
These trees, by locals referred to as Queñua, Yagual and other names, can be found at altitudes of 4,500 m (14,760 ft) above sea level. It remains unclear if the patchy distribution of these forests and woodlands is natural, or the result of clearing which began during the Incan period. Regardless, in modern times the clearance has accelerated, and the trees are now considered to be highly endangered, with some believing that as little as 10% of the original woodland remains.^[16]

Fauna

A male Andean Cock-of-the-rock, a species found in humid Andean forests of Peru, the country of which it is the national bird.

Herds of alpacas in the foothills near Ausangate mountain.

The Andes is rich in fauna: With almost 3,500 species, of which roughly 2/3 are endemic to the region, the Andes is the most important region in the world for amphibians.^[15] The diversity of animals in the Andes is high, with almost 600 species of mammals (13% endemic), more than 1,700 species of birds (about 1/3 endemic), more than 600 species of reptile (about 45% endemic), and almost 400 species of fish (about 1/3 endemic).^[15]

The Vicuña and Guanaco can be found living in the Altiplano, while the closely related domesticated Llama and Alpaca are widely kept by locals as pack animals and for their meat and wool. The crepuscular (active during dawn and dusk) chinchillas, two threatened members of the rodent order, inhabit the Andes' alpine regions. The Andean Condor, the largest bird of its kind in the Western Hemisphere, occurs throughout much of the Andes but generally in very low densities. Other animals found in the relatively open habitats of the high Andes include the huemul, cougar, foxes in the genus Pseudalopex, and, for birds, certain species of tinamous (notably members of the genus Nothoprocta), Andean Goose, Giant Coot, flamingos (mainly associated with hypersaline lakes), Lesser Rhea, Andean Flicker, Diademed Sandpiper-plover, miners, sierra-finches and diuca-finches.

Lake Titicaca hosts several endemics, among them the highly endangered Titicaca Flightless Grebe and Titicaca Water Frog. A few species of hummingbirds, notably some hillstars, can be seen at altitudes above 4,000 m (13,100 ft), but far higher diversities can be found at lower altitudes, especially in the humid Andean forests ("cloud forests") growing on slopes in Colombia, Ecuador, Peru, Bolivia and far northwestern Argentina. These forest-types, which includes the Yungas and parts of the Chocó, are very rich in flora and fauna, although few large mammals exists, exceptions being the threatened Mountain Tapir, Spectacled Bear and Yellow-tailed Woolly Monkey.

Birds of humid Andean forests include mountain-toucans, quetzals and the Andean Cock-of-the-rock, while mixed species flocks dominated by tanagers and Furnariids commonly are seen - in contrast to several vocal but typically cryptic species of wrens, tapaculos and antpittas.

A number of species such as the Royal Cinclodes and White-browed Tit-spinetail are associated with Polylepis, and consequently also threatened.

Human activity

The Andes mountains form a north-south axis of cultural influences. A long series of cultural development culminated in the expansion of the Inca civilization and Inca Empire in the central Andes during the 15th century. The Incas formed this civilization through imperialistic militarism as well as careful and meticulous governmental management.^[17] The government sponsored the construction of aqueducts and roads in addition to preexisting installations. Some of these constructions are still in existence today.
Devastated by European diseases to which they had no immunity, and civil wars, in 1532 the Incas were defeated by an alliance composed of tens of thousands allies from nations they had subjugated (e.g. Huancas, Chachapoyas, Cañaris) and a small army of 180 Spaniards led by Francisco Pizarro. One of the few Inca sites the Spanish never found in their conquest was Machu Picchu, which lay hidden on a peak on the eastern edge of the Andes where they descend to the Amazon. The main surviving languages of the Andean peoples are those of the Quechua and Aymara language families. Woodbine Parish and Joseph Barclay Pentland surveyed a large part of the Bolivian Andes from 1826 to 1827.

In modern times, the largest Andean cities are Bogotá, Colombia, with a population of about eight million, Santiago de Chile, and Medellin, Colombia.

Transportation

Several major cities are either in the Andes or in the foothills, among which are Bogotá, Medellín and Cali, Colombia; Quito, Ecuador; Mérida, Venezuela; La Paz, Bolivia; Santiago, Chile, and Cusco, Peru. These and most other cities and large towns are connected with asphalt-paved roads, while smaller towns are often connected by dirt roads, which may require a four-wheel-drive vehicle.^[18]
The rough terrain has historically put the costs of building highways and railroads that cross the Andes out of reach of most neighboring countries, even with modern civil engineering practices. For example, the main crossover of the Andes between Argentina and Chile is still accomplished through the Paso Internacional Los Libertadores. Only recently the ends of some highways that came rather close to one another from the east and the west have been connected.^[19] Much of the transportation of passengers is done via aircraft.

However, there is one railroad that connects Chile with Argentina via the Andes, and there are others that make the same connection via southern Bolivia. See railroad maps of that region.

There is one or more highway in Bolivia that cross the Andes. Some of these were built during a period of war between Bolivia and Paraguay, in order to transport Bolivian troops and their supplies to the war front in the lowlands of southeastern Bolivia and western Paraguay.

For decades, Chile claimed ownership of land on the eastern side of the Andes. However, these claims were given up in about 1870 during the War of the Pacific between Chile, the allied Bolivia and Peru, in a diplomatic deal to keep Argentina out of the war. The Chilean Army and Chilean Navy defeated the combined forces of Bolivia and Peru, and Chile took over Bolivia's only province on the Pacific Coast, some land from Peru that was returned to Peru decades later. Bolivia has been a completely landlocked country ever since. It mostly uses seaports in eastern Argentina and Uruguay for international trade because its diplomatic relations with Chile have been suspended since 1978.

Because of the tortuous terrain in places, villages and towns in the mountains — to which travel via motorized vehicles are of little use — are still located in the high Andes of Argentina, Bolivia, Peru, and Ecuador. Locally, the relatives of the camel, the llama, and the alpaca continue to carry out important uses as pack animals, but this use has generally diminished in modern times. Donkeys, mules, and horses are also useful.

Agriculture

Photograph of young Peruvian farmers sowing maize and beans.

The ancient peoples of the Andes such as the Incas have practiced irrigation techniques for over 6,000 years. Because of the mountain slopes, terracing has been a common practice. Terracing, however, was only extensively employed after Incan imperial expansions to fuel their expanding realm. The potato holds a very important role as an internally consumed staple crop. Maize was also an important crop for these people, and was used for the production of chicha, important to Andean native people. Currently, tobacco, cotton and coffee are the main export crops. Coca, despite eradication programmes in some countries, remains an important crop for legal local use in a mildly stimulating herbal tea, and, both controversially and illegally, for the production of cocaine.

Mining

The Andes rose to fame for its mineral wealth during the Spanish conquest of South America. Although Andean Amerindian peoples crafted ceremonial jewelry of gold and other metals the mineralizations of the Andes were first mined in large scale after the Spanish arrival. Potosí in present-day Bolivia and Cerro de Pasco in Peru were one of the principal mines of the Spanish Empire in the New World. Río de la Plata and Argentina derive their names from the silver of Potosí.
Currently, mining in the Andes of Chile and Peru places these countries as the first and third major producers of copper in the world. Peru also contains the largest goldmine in the world: the Yanacocha. The Bolivian Andes produce principally tin although historically silver mining had a huge impact on the economy of 17th century Europe.

There is a long history of mining in the Andes, from the Spanish silver mines in Potosí in the 16th century to the vast current porphyry copper deposits of Chuquicamata and Escondida in Chile and Toquepala in Peru. Other metals including iron, gold and tin in addition to non-metallic resources are important.

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  Chilean huasos, 19th century
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  The mountain Huayna Picchu overlooks the ruins of Machu Picchu
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  Quechua woman and child in the Sacred Valley in Peru

Peaks

This list contains some of the major peaks in the Andes mountain range. The highest peak is Aconcagua of Argentina (see below).

Argentina

Tronador, Argentina/Chile

• Aconcagua, 6,962 m (22,841 ft)
• Cerro Bonete, 6,759 m (22,175 ft)
• Galán, 5,912 m (19,396 ft)
• Mercedario, 6,720 m (22,047 ft)
• Pissis, 6,795 m (22,293 ft)

Border between Argentina and Chile

• Cerro Bayo, 5,401 m (17,720 ft)
• Cerro Fitz Roy, 3,375 m (11,073 ft) or 3,405 m, Patagonia, also known as Cerro Chaltén
• Cerro Escorial, 5,447 m (17,871 ft)
• Cordón del Azufre, 5,463 m (17,923 ft)
• Falso Azufre, 5,890 m (19,324 ft)
• Incahuasi, 6,620 m (21,719 ft)
• Lastarria, 5,697 m (18,691 ft)
• Llullaillaco, 6,739 m (22,110 ft)
• Maipo, 5,264 m (17,270 ft)
• Marmolejo, 6,110 m (20,046 ft)
• Ojos del Salado, 6,893 m (22,615 ft)
• Olca, 5,407 m (17,740 ft)
• Sierra Nevada de Lagunas Bravas, 6,127 m (20,102 ft)
• Socompa, 6,051 m (19,852 ft)
• Nevado Tres Cruces, 6,749 m (22,142 ft) (south summit) (III Region)
• Tronador, 3,491 m (11,453 ft)
• Tupungato, 6,570 m (21,555 ft)
• Nacimiento, 6,492 m (21,299 ft)

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  Llullaillaco, Argentina/Chile

Bolivia

• Janq'u Uma, 6,427 m (21,086 ft)
• Cabaraya, 5,860 m (19,226 ft)
• Chacaltaya, 5,421 m (17,785 ft)
• Wayna Potosí, 6,088 m (19,974 ft)
• Illampu, 6,368 m (20,892 ft)
• Illimani, 6,438 m (21,122 ft)
• Laram Q'awa, 5,520 m (18,110 ft)
• Macizo de Pacuni, 5,400 m (17,720 ft)
• Nevado Anallajsi, 5,750 m (18,865 ft)
• Nevado Sajama, 6,542 m (21,463 ft)
• Patilla Pata, 5,300 m (17,390 ft)
• Tata Sabaya, 5,430 m (17,815 ft)

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  Sajama
  
• 

  Wayna Potosí
  

Border between Bolivia and Chile

• Acotango, 6,052 m (19,856 ft)
• Michincha, 5,305 m (17,405 ft)
• Iru Phutunqu, 5,163 m (16,939 ft)
• Licancabur, 5,920 m (19,423 ft)
• Olca, 5,407 m (17,740 ft)
• Parinacota, 6,348 m (20,827 ft)
• Paruma, 5,420 m (17,782 ft)
• Pomerape, 6,282 m (20,610 ft)

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  Licancabur, Bolivia/Chile
  
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  Parinacota
  

Chile

• Monte San Valentin, 4,058 m (13,314 ft)
• Cerro Paine Grande, 2,884 m (9,462 ft)
• Cerro Macá, c.2,300 m (7,546 ft)
• Monte Darwin, c.2,500 m (8,202 ft)
• Volcan Hudson, c.1,900 m (6,234 ft)
• Cerro Castillo Dynevor, c.1,100 m (3,609 ft)
• Mount Tarn, c.825 m (2,707 ft)
• Polleras, 5,993 m (19,662 ft)

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  Santiago de Chile on the western slopes of a snowcapped Andes
  
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  View of Cuernos del Paine in Torres del Paine National Park
  

Colombia

• Pico Cristóbal Colón, 5,775 m (18,947 ft)
• Nevado del Huila, 5,365 m (17,602 ft)
• Nevado del Ruiz, 5,321 m (17,457 ft)
• Nevado del Tolima, 5,205 m (17,077 ft)
• Pico Pan de Azucar, 5,200 m (17,060 ft)
• Ritacuba Negra, 5,320 m (17,454 ft)
• Nevado del Cumbal, 4,764 m (15,630 ft)
• Cerro Negro de Mayasquer, 4,445 m (14,583 ft)
• Ritacuba Blanco, 5,410 m (17,749 ft)
• Nevado del Quindío, 5,215 m (17,110 ft)
• Purace, 4,655 m (15,272 ft)
• Santa Isabel, 4,955 m (16,257 ft)
• Doña Juana, 4,150 m (13,615 ft)
• Galeras, 4,276 m (14,029 ft)
• Azufral. 4,070 m (13,353 ft)

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  Ritacuba blanco the highest peak of Cordillera Oriental, Colombia.
  
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  Nevado del Ruiz, Colombia
  

Ecuador

• Antisana, 5,752 m (18,871 ft)
• Cayambe, 5,790 m (18,996 ft)
• Chimborazo, 6,268 m (20,564 ft)
• Corazón, 4,790 m (15,715 ft)
• Cotopaxi, 5,897 m (19,347 ft)
• El Altar, 5,320 m (17,454 ft)
• Illiniza, 5,248 m (17,218 ft)
• Pichincha, 4,784 m (15,696 ft)
• Quilotoa, 3,914 m (12,841 ft)
• Reventador, 3,562 m (11,686 ft)
• Sangay, 5,230 m (17,159 ft)
• Tungurahua, 5,023 m (16,480 ft)
• Titicacha, 5,035 m (16,519 ft)

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  Chimborazo near Riobamba, Ecuador
  
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  Tungurahua, Ecuador
  
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  Cayambe, Ecuador
  
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  Volcán El Altar - Riobamba - Ecuador
  
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  Cotopaxi
  
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  Andes near Otavalo
  
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  Pichincha Volcano, an active stratovolcano in the Ecuadorian Andes photographed from the Historic Center of Quito
  
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  Imbabura Volcano, an inactive stratovolcano
  

Peru

• Alpamayo, 5,947 m (19,511 ft)
• Artesonraju, 6,025 m (19,767 ft)
• Carnicero, 5,960 m (19,554 ft)
• Chumpi, 6,106 m (20,033 ft)
• El Misti, 5,822 m (19,101 ft)
• El Toro, 5,830 m (19,127 ft)
• Huandoy, 6,395 m (20,981 ft)
• Huascarán, 6,768 m (22,205 ft)
• Jirishanca, 6,094 m (19,993 ft)
• Pumasillu, 5,991 m (19,656 ft)
• Rasaq, 6,040 m (19,816 ft)
• Runtuy, 5,870 m (19,259 ft)
• Sarapu, 6,127 m (20,102 ft)
• Seria Norte, 5,860 m (19,226 ft)
• Siula Grande, 6,344 m (20,814 ft)
• Waytapallana, 5,557 m (18,232 ft)
• Yerupaja, 6,635 m (21,768 ft)
• Yerupaja Chico, 6,089 m (19,977 ft)

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  Alpamayo, Peru
  
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  Chachani and El Misti, Peru
  
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  Huandoy, Peru
  
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  Yerupaja
  

Venezuela

• Pico Bolívar, 5,007 m (16,427 ft)
• Pico Humboldt, 4,940 m (16,207 ft)
• Pico Bonpland, 4,880 m (16,010 ft)
• Pico La Concha, 4,870 m (15,978 ft)
• Pico Piedras Blancas, 4,740 m (15,551 ft)
• Pico El Águila, 4,180 m (13,714 ft)
• Pico El Toro 4,729 m (15,515 ft)
• Pico El León 4,740 m (15,551 ft)
• Pico Mucuñuque 4,609 m (15,121 ft)

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  Pico Bolívar, Venezuela
  
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  Pico Humboldt, Venezuela
  
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  Pico La Concha, Venezuela
  
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  Pico El Águila, Venezuela
  
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  Pico El Toro, Venezuela
  
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  Pico León, Venezuela
  
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  Pico Mucuñuque, Venezuela
  

Hominidae

From Wikipedia, the free encyclopedia

Hominids[1] Temporal range: Miocene - Holocene, 7–0Ma PreЄ Є O S D C P T J K Pg N
Two hominids: A human (Homo sapiens) and a chimpanzee (Pan troglodytes)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Primates
Superfamily:	Hominoidea
Family:	Hominidae Gray, 1825
Type genus
Homo Linnaeus, 1758
Genera
Subfamily Ponginae Pongo – orangutans Subfamily Homininae †Australopithecina Gorilla – gorillas Homo – humans Pan – chimpanzees and bonobos
Synonyms
Pongidae Elliot, 1913

The Hominidae (/hɒˈmɪnɨdiː/; also known as great apes^{[notes 1]}) form a taxonomic family of primates, including four extant genera:

• chimpanzees (Pan) – 2 species
• gorillas (Gorilla) – 2 species
• humans (Homo) – 1 species
• orangutans (Pongo) – 2 species.^[1]

The term "hominid" is also used in the more restricted sense as hominins or "humans and relatives of humans closer than chimpanzees".^[2] In this usage, all hominid species other than Homo sapiens are extinct. A number of known extinct genera are grouped with humans in the Homininae subfamily, others with orangutans in the Ponginae subfamily. The most recent common ancestor of the Hominidae lived roughly 14 million years ago,^[3] when the ancestors of the orangutans speciated from the ancestors of the other three genera.^[4] The ancestors of the Hominidae family had already speciated from those of the Hylobatidae family, perhaps 15 million to 20 million years ago.^[4][5]

History

See also: Human evolution

Sumatran orangutan (Pongo abelii)

In the early Miocene, about 22 million years ago, the many kinds of arboreally adapted primitive catarrhines from East Africa suggest a long history of prior diversification. Fossils at 20 million years ago include fragments attributed to Victoriapithecus, the earliest Old World Monkey. Among the genera thought to be in the ape lineage leading up to 13 million years ago are Proconsul, Rangwapithecus, Dendropithecus, Limnopithecus, Nacholapithecus, Equatorius, Nyanzapithecus, Afropithecus, Heliopithecus, and Kenyapithecus, all from East Africa. The presence of other generalized non-cercopithecids of middle Miocene age from sites far distant—Otavipithecus from cave deposits in Namibia, and Pierolapithecus and Dryopithecus from France, Spain and Austria—is evidence of a wide diversity of forms across Africa and the Mediterranean basin during the relatively warm and equable climatic regimes of the early and middle Miocene. The youngest of the Miocene hominoids, Oreopithecus, is from coal beds in Italy that have been dated to 9 million years ago.
Molecular evidence indicates that the lineage of gibbons (family Hylobatidae) diverged from great apes some 18–12 million years ago, and that of orangutans (subfamily Ponginae) diverged from the other great apes at about 12 million years; there are no fossils that clearly document the ancestry of gibbons, which may have originated in a so-far-unknown South East Asian hominoid population, but fossil proto-orangutans may be represented by Sivapithecus from India and Griphopithecus from Turkey, dated to around 10 million years ago.^[6]

A reconstruction of a female Australopithecus afarensis (National Museum of Natural History)

Species close to the last common ancestor of gorillas, chimpanzees, bonobos and humans may be represented by Nakalipithecus fossils found in Kenya and Ouranopithecus found in Greece. Molecular evidence suggests that between 8 and 4 million years ago, first the gorillas, and then the chimpanzees and bonobos (genus Pan) split off from the line leading to the humans; human DNA is approximately 98.4% identical to that of chimpanzees when comparing single nucleotide polymorphisms (see human evolutionary genetics). The fossil record of gorillas, chimpanzees and bonobos is limited. Poor preservation in certain conditions (e.g. rain forest soils tend to be acidic and dissolve bone) contributes to this problem and to sampling bias. Other hominins likely adapted to the drier environments outside the equatorial belt, along with antelopes, hyenas, dogs, pigs, elephants, and horses. The wet equatorial belt contracted after about 8 million years ago. There is very little fossil evidence for the split of the hominin lineage from the lineages of gorillas and Pan (chimpanzees and bonobos). The earliest fossils that have been argued to belong to the human lineage are Sahelanthropus tchadensis (7 Ma) and Orrorin tugenensis (6 Ma), followed by Ardipithecus (5.5–4.4 Ma), with species Ar. kadabba and Ar. ramidus.

Taxonomic history

Humans are one of the four extant hominid genera.

The classification of the great apes has been revised several times in the last few decades. These various revisions have led to a varied use of the word "hominid" – the original meaning of Hominidae referred only to the modern meaning of Hominini, i.e. only humans and their closest relatives. The meaning of the taxon changed gradually, leading to the modern meaning of "hominid", which includes all great apes and humans.

A model of a modern human hominid skull

A fossil hominid exhibit at The Museum of Osteology, Oklahoma City, Oklahoma

The primatological term hominid is easily confused with a number of very similar words:

• A hominoid, commonly called an ape, is a member of the superfamily Hominoidea: extant members are the lesser apes (gibbons) and great apes.
• A hominine is a member of the subfamily Homininae: gorillas, chimpanzees, bonobos and humans (excludes orangutans).
• A hominin is a member of the tribe Hominini: modern humans and their extinct relatives.
• A human is a member of the genus Homo, of which Homo sapiens is the only extant species, and within that Homo sapiens sapiens is the only surviving subspecies.

Many scientists, including paleoanthropologists, continue to use the term hominid to mean humans and their direct and near-direct bipedal ancestors.

As mentioned, Hominidae was originally the name given to humans and their extinct relatives, with the other great apes being placed in a separate family, the Pongidae. However, that definition made Pongidae paraphyletic because at least one great ape species appears to be more closely related to humans than to other great apes. Most taxonomists nowadays encourage monophyletic groups – this would require the use of Pongidae to be restricted to one of the great ape groups (containing Pongo, the orangutans) only. Thus, many biologists consider Hominidae to include Pongidae as the subfamily Ponginae, or restrict the latter to the orangutans and their extinct relatives, such as Gigantopithecus. The taxonomy shown here follows the monophyletic groupings according to the modern understanding of human and great ape relationships.

Especially close human relatives form a subfamily, the Homininae. A few researchers go so far as to include chimpanzees and bonobos^[7] and gorillas^[8][9] in the genus Homo along with humans. Alternatively, those fossil relatives more closely related to humans than the nearest living great ape species represent members of Hominidae without necessarily assigning subfamily or tribal categories.^[10]

Many extinct hominids have been studied to help understand the relationship between modern humans and the other extant hominids. Some of the extinct members of this family include Gigantopithecus, Orrorin, Ardipithecus, Kenyanthropus, and the australopithecines Australopithecus and Paranthropus.^[11]

The exact criteria for membership in the tribe Hominini under the current understanding of human origins are not clear, but the taxon generally includes those species that share more than 97% of their DNA with the modern human genome, and exhibit a capacity for language or for simple cultures beyond the family or band. The theory of mind including such faculties as mental state attribution, empathy and even empathetic deception is a controversial criterion distinguishing the adult human alone among the hominids. Humans acquire this capacity at about four and a half years of age, whereas it has neither been proven nor disproven that gorillas, chimpanzees and bonobos develop a theory of mind.^[12] This is also the case for some New World monkeys outside the family of great apes, as, for example, the capuchin monkeys.

However, without the ability to test whether early members of the Hominini (such as Homo erectus, Homo neanderthalensis, or even the australopithecines) had a theory of mind, it is difficult to ignore similarities seen in their living cousins. Orangutans have also been shown to have culture comparable to that of chimpanzees,^[13] and some^[who?] say the orangutan may also satisfy these criteria. These scientific debates take on political significance for advocates of great ape personhood.

Classification

 

Evolutionary tree of the Hominoidea : after an initial 

separation from the main line of Hylobatidae (current gibbons), some 18 million years ago, the line of Pongidae broke away, leading to the current orangutan, while the Hominidae split later in Gorillini and Hominini.

Extant

Skulls of an orangutan and a gorilla

Human and chimp skulls and brains (not to scale), as illustrated in Gervais' Histoire naturelle des mammifères

The seven living species of great ape are classified in four genera. The following classification is commonly accepted:^[1]

• Family Hominidae: humans and other great apes; extinct genera and species excluded^[1]
  • Subfamily Ponginae
    • Tribe Pongini
      • Genus Pongo
        • Bornean orangutan, Pongo pygmaeus
          • Pongo pygmaeus pygmaeus
          • Pongo pygmaeus morio
          • Pongo pygmaeus wurmbii
        • Sumatran orangutan, Pongo abelii
  • Subfamily Homininae
    • Tribe Gorillini
      • Genus Gorilla
        • Western gorilla, Gorilla gorilla
          • Western lowland gorilla, Gorilla gorilla gorilla
          • Cross River gorilla, Gorilla gorilla diehli
        • Eastern gorilla, Gorilla beringei
          • Mountain gorilla, Gorilla beringei beringei
          • Eastern lowland gorilla, Gorilla beringei graueri
    • Tribe Hominini
      • Subtribe Panina
        • Genus Pan
          • Chimpanzee (common chimpanzee), Pan troglodytes
            • Central chimpanzee, Pan troglodytes troglodytes
            • Western chimpanzee, Pan troglodytes verus
            • Nigeria-Cameroon chimpanzee, Pan troglodytes ellioti
            • Eastern chimpanzee, Pan troglodytes schweinfurthii
          • Bonobo (pygmy chimpanzee), Pan paniscus
      • Subtribe Hominina
        • Genus Homo
          • Human, Homo sapiens
            • Anatomically modern human, Homo sapiens sapiens

Fossil

A reconstruction of Pierolapithecus catalaunicus

Replica of the skull sometimes known as "Nutcracker Man", found by Mary Leakey.

In addition to the extant species and subspecies above, archaeologists, paleontologists, and anthropologists have discovered numerous extinct great ape species. Below is based on the following taxonomy.^[14]

Family Hominidae

• Graecopithecus (?=Ouranopithecus)† (placement debated)
  • Graecopithecus freybergi (?=Ouranopithecus macedoniensis)
• Otavipithecus†
  • Otavipithecus namibiensis
• Morotopithecus†
  • Morotopithecus bishopi
• Subfamily Ponginae^[15]
  • Tribe Lufengpithecini†
    • Lufengpithecus
      • Lufengpithecus lufengensis
      • Lufengpithecus keiyuanensis
      • Lufengpithecus hudienensis
  • Tribe Sivapithecini†
    • Ankarapithecus
      • Ankarapithecus meteai
    • Sivapithecus
      • Sivapithecus brevirostris
      • Sivapithecus punjabicus
      • Sivapithecus parvada
      • Sivapithecus sivalensis
      • Sivapithecus indicus
    • Gigantopithecus
      • Gigantopithecus bilaspurensis
      • Gigantopithecus blacki
      • Gigantopithecus giganteus
  • Tribe Pongini
    • Khoratpithecus†
      • Khoratpithecus ayeyarwadyensis
      • Khoratpithecus piriyai
      • Khoratpithecus chiangmuanensis
    • Pongo (orangutans)
      • Pongo hooijer†
• Subfamily Homininae^[16][17]
  • Pierolapithecus†
    • Pierolapithecus catalaunicus
  • Udabnopithecus†
    • Udabnopithecus garedziensis
  • Tribe Dryopithecini†
    • Oreopithecus (placement disputed)
      • Oreopithecus bambolii
    • Nakalipithecus
      • Nakalipithecus nakayamai
    • Anoiapithecus
      • Anoiapithecus brevirostris
    • Dryopithecus
      • Dryopithecus wuduensis
      • Dryopithecus fontani
      • Dryopithecus brancoi
      • Dryopithecus laietanus
      • Dryopithecus crusafonti
  • Rudapithecus†
    • Rudapithecus hungaricus
  • Samburupithecus†
    • Samburupithecus kiptalami
  • Tribe Gorillini
    • Chororapithecus † (placement debated)
      • Chororapithecus abyssinicus
  • Tribe Hominini
    • Sahelanthropus† (hominin status highly problematic)
      • Sahelanthropus tchadensis
    • Orrorin†
      • Orrorin tugenensis
    • Subtribe Hominina
      • Ardipithecus†
        • Ardipithecus ramidus
        • Ardipithecus kadabba
      • Kenyanthropus† (placement debated)
        • Kenyanthropus platyops
      • Praeanthropus†^[18]
        • Praeanthropus bahrelghazali
        • Praeanthropus anamensis
        • Praeanthropus afarensis
      • Australopithecus†
        • Australopithecus africanus
        • Australopithecus garhi
        • Australopithecus sediba
      • Paranthropus†
        • Paranthropus aethiopicus
        • Paranthropus robustus
        • Paranthropus boisei
      • Homo – immediate ancestors of modern humans
        • Homo gautengensis†
        • Homo rudolfensis†
        • Homo habilis†
        • Homo floresiensis†
        • Homo erectus†
        • Homo ergaster†
        • Homo antecessor†
        • Homo heidelbergensis†
        • Homo cepranensis†
        • Denisovans (scientific name has not yet been assigned)†
        • Homo neanderthalensis†
        • Homo rhodesiensis†
        • Homo sapiens
          • Homo sapiens idaltu†
          • Archaic Homo sapiens (Cro-Magnon)†
          • Red Deer Cave people† (scientific name has not yet been assigned; perhaps a race of modern humans or a hybrid^[19] of modern humans and Denisovans^[20])

Physical description

The great apes are large, tailless primates, with the smallest living species being the bonobo at 30–40 kilograms in weight, and the largest being the gorillas, with males weighing 140–180 kilograms. In all great apes, the males are, on average, larger and stronger than the females, although the degree of sexual dimorphism varies greatly among species. Although most living species are predominantly quadrupedal, they are all able to use their hands for gathering food or nesting materials, and, in some cases, for tool use.^[21]

Most species are omnivorous,^{[citation needed]} but fruit is the preferred food among all but some human groups. Chimpanzees and orangutans primarily eat fruit. When gorillas run short of fruit at certain times of the year or in certain regions, they resort to eating shoots and leaves, often of bamboo, a type of grass. Gorillas have extreme adaptations for chewing and digesting such low-quality forage, but they still prefer fruit when it is available, often going miles out of their way to find especially preferred fruits. Humans, since the neolithic revolution, consume mostly cereals and other starchy foods, including increasingly highly processed foods, as well as many other domesticated plants (including fruits) and meat. Hominid teeth are similar to those of the Old World monkeys and gibbons, although they are especially large in gorillas. The dental formula is 2.1.2.32.1.2.3. Human teeth and jaws are markedly smaller for their size than those of other apes, which may be an adaptation to eating cooked food for more than a million years.^[22][23]

Gorilla

Gestation in great apes lasts 8–9 months, and results in the birth of a single offspring, or, rarely, twins. The young are born helpless, and they must be cared for long periods of time. Compared with most other mammals, great apes have a remarkably long adolescence, not being weaned for several years, and not becoming fully mature for eight to thirteen years in most species (longer in humans). As a result, females typically give birth only once every few years. There is no distinct breeding season.^[21]

Gorillas and chimpanzees live in family groups of around five to ten individuals, although much larger groups are sometimes noted. Chimpanzees live in larger groups that break up into smaller groups when fruit becomes less available. When small groups of female chimpanzees go off in separate directions to forage for fruit, the dominant male(s) can no longer control them and the females often mate with other subordinate males, whether by choice or not. In contrast, groups of gorillas stay together regardless of the availability of fruit. When fruit is hard to find, they resort to eating leaves and shoots. Because gorilla groups stay together, the male is able to monopolize the females in his group. This fact is related to gorillas' greater sexual dimorphism than chimpanzees'. In both chimpanzees and gorillas, the groups include at least one dominant male, and females leave the group at maturity.

Legal status

Due to the close genetic relationship between humans and other great apes, certain animal rights organizations, such as the Great Ape Project, argue that nonhuman great apes are persons and should be given basic human rights. Some countries have instituted a research ban to protect great apes from any kind of scientific testing.

On 25 June 2008, the Spanish parliament supported a new law that would make "keeping apes for circuses, television commercials or filming" illegal.^[24]

Conservation

The following table lists the estimated number of great ape individuals living outside zoos.

Species	Estimated number
Sumatran orangutan	6,667[25]
Bornean orangutan	61,234[25]
Western gorilla	200,000[26]
Eastern gorilla	6,000[26]
Common chimpanzee	100,000[27]
Bonobo	10,000[27]
Human	7,300,722,300 [28]