Wushan Man
Encyclopedia
Wushan Man is a controversial taxon
Taxon
|thumb|270px|[[African elephants]] form a widely-accepted taxon, the [[genus]] LoxodontaA taxon is a group of organisms, which a taxonomist adjudges to be a unit. Usually a taxon is given a name and a rank, although neither is a requirement...

. Originally considered a subspecies of Homo erectus
Homo erectus
Homo erectus is an extinct species of hominid that lived from the end of the Pliocene epoch to the later Pleistocene, about . The species originated in Africa and spread as far as India, China and Java. There is still disagreement on the subject of the classification, ancestry, and progeny of H...

, it is now thought by one of the scientists, Russell Ciochon
Russell Ciochon
Russell Ciochon is an American paleoanthropologist. He was born in Altadena, California and received three degrees in anthropology from the University of California, Berkeley. He is currently a professor of anthropology at the University of Iowa...

, that first described it to be based upon fossilized fragments of an extinct non-hominin
Hominini
Hominini is the tribe of Homininae that comprises Homo, and the two species of the genus Pan , their ancestors, and the extinct lineages of their common ancestor . Members of the tribe are called hominins...

 ape
Ape
Apes are Old World anthropoid mammals, more specifically a clade of tailless catarrhine primates, belonging to the biological superfamily Hominoidea. The apes are native to Africa and South-east Asia, although in relatively recent times humans have spread all over the world...

. The remains that have become known as "Wushan Man" were found in 1985 in Longgupo (literally "Dragon Bone Slope" which is an alternate English name for it), Zhenlongping Village, Miaoyu Town of Wushan County, Chongqing in the Three Gorges area of China 20 kilometres (12.4 mi) south of the Yangtze River
Yangtze River
The Yangtze, Yangzi or Cháng Jiāng is the longest river in Asia, and the third-longest in the world. It flows for from the glaciers on the Tibetan Plateau in Qinghai eastward across southwest, central and eastern China before emptying into the East China Sea at Shanghai. It is also one of the...

. They have been dated to around two million years ago.

History of find

The cave at Longgupo, "Dragon Bone Slope," due the way the collapse of the cave's roof and walls shaped the above land.fig. 1 It was discovered as a site contain fossils in 1984 and then initially excavated by a team of Chinese scientists, led by Huang Wanpo of the Institute of Vertebrate Paleontology and Paleoanthropology
Institute of Vertebrate Paleontology and Paleoanthropology
The Institute of Vertebrate Paleontology and Paleoanthropology of China is a prominent research institution and collections repository for fossils, including many dinosaur and pterosaurand cat poo specimens...

 in Beijing
Beijing
Beijing , also known as Peking , is the capital of the People's Republic of China and one of the most populous cities in the world, with a population of 19,612,368 as of 2010. The city is the country's political, cultural, and educational center, and home to the headquarters for most of China's...

 and the Chongqing National Museum (Sichuan
Sichuan
' , known formerly in the West by its postal map spellings of Szechwan or Szechuan is a province in Southwest China with its capital in Chengdu...

 Province) from 1985 to until 1988. The deposits on the cave floor are over 22 m deep, with the 10 m containing fossils overlain by 12 m that do not.fig. 2 In 1986, three fore-teeth and a left mandible with two molars were unearthed together with the animal fossils including teeth from an extinct type of large ape Gigantopithecus
Gigantopithecus
Gigantopithecus is an extinct genus of ape that existed from roughly one million years to as recently as three hundred thousand years ago, in what is now China, India, and Vietnam, placing Gigantopithecus in the same time frame and geographical location as several hominin species...

 and an extinct pygmy giant panda Ailuropoda microta
Ailuropoda microta
Ailuropoda microta, rarely called the Dwarf Panda, Dwarf Giant Panda, or Pygmy Giant Panda, is the earliest known ancestor of the Giant Panda. It measured 1 m in length; the modern Giant Panda grows to a size in excess of 1.5 m . Wear patterns on its teeth suggest it lived on a diet of...

. Excavations carried between 1997 and 1999 and then between 2003 and 2006 have found additional stone tools and animal fossils including remains of 120 species of vertebrates, of which 116 are mammals. This suggests the fossils existed originally in a subtropical forest environment.

The presence of Sinomastodon
Sinomastodon
Sinomastodon is an extinct gomphothere genus , from the Late Miocene to the Early Pleistocene deposits of south-east Asia...

, Nestoritherium
Nestoritherium
Nestoritherium is an extinct genus of chalicothere....

, Equus yunnanensis, Ailuropoda microta
Ailuropoda microta
Ailuropoda microta, rarely called the Dwarf Panda, Dwarf Giant Panda, or Pygmy Giant Panda, is the earliest known ancestor of the Giant Panda. It measured 1 m in length; the modern Giant Panda grows to a size in excess of 1.5 m . Wear patterns on its teeth suggest it lived on a diet of...

 remains in the level containing the jaw suggested that its remains belonged to the earliest part of the Pleistocene
Pleistocene
The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....

 or late Pliocene
Pliocene
The Pliocene Epoch is the period in the geologic timescale that extends from 5.332 million to 2.588 million years before present. It is the second and youngest epoch of the Neogene Period in the Cenozoic Era. The Pliocene follows the Miocene Epoch and is followed by the Pleistocene Epoch...

. Dating of the layers containing the fossil remains was initially done using archaeomagnetic dating
Archaeomagnetic dating
Archaeomagnetic dating is the study and interpretation of the signatures of the Earth's magnetic field at past times recorded in archaeological materials. These paleomagnetic signatures are fixed when ferromagnetic materials such as magnetite cool below the Curie point, freezing the magnetic moment...

 of traces of the Earth's ancient magnetic field. These confirmed a Pleistocene age linking the fossil jaw to around 1.78 million to 1.96 million years ago and so the same time as the human fossils that appeared in Africa's Olduvai Gorge
Olduvai Gorge
The Olduvai Gorge is a steep-sided ravine in the Great Rift Valley that stretches through eastern Africa. It is in the eastern Serengeti Plains in northern Tanzania and is about long. It is located 45 km from the Laetoli archaeological site...

. Later in 1992, a joint Chinese-American-Canadian research team using electron spin resonance
Electron paramagnetic resonance
Electron paramagnetic resonance or electron spin resonance spectroscopyis a technique for studying chemical species that have one or more unpaired electrons, such as organic and inorganic free radicals or inorganic complexes possessing a transition metal ion...

 dating and a deer tooth from one of the cave's upper levels three meters above that containing the jaw dated this level to a minimum age of 750,000 years and a most likely age of 1 million making the layers below at least and probably much older in date than this. More recent dating techniques suggest the layer containing the fossils are 2 million to 2.04 million years old.

Early reports of the excavation were in Chinese journals and did not gather attention from outside China. In 1992, Russell Ciochon
Russell Ciochon
Russell Ciochon is an American paleoanthropologist. He was born in Altadena, California and received three degrees in anthropology from the University of California, Berkeley. He is currently a professor of anthropology at the University of Iowa...

 was invited to Longgupo to examine and provide a reliable age for the jaw. This led to the published in 1995 by Ciochon and Chinese paleoanthropologist of the findings in the journal Nature
Nature (journal)
Nature, first published on 4 November 1869, is ranked the world's most cited interdisciplinary scientific journal by the Science Edition of the 2010 Journal Citation Reports...

.

Importance

According to the Nature paper

The new evidence suggests that hominids entered Asia before 2 Myr, coincident with the earliest diversification of genus Homo in Africa. Clearly, the first hominid to arrive in Asia was a species other than true H. erectus, and one that possessed a stone-based technology. A pre-erectus hominid in China as early as 1.9 Myr provides the most likely antecedents for the in situ evolution of Homo erectus in Asia.p. 278


This makes its status as a Homo fossil critically important to the study of humans origins as it suggests that H. erectus was not the first human species to leave Africa and supports the argument made by some that H. erectus evolved in Asia and not Africa.

The discovery of Homo floresiensis
Homo floresiensis
Homo floresiensis is a possible species, now extinct, in the genus Homo. The remains were discovered in 2003 on the island of Flores in Indonesia. Partial skeletons of nine individuals have been recovered, including one complete cranium...

 also makes evidence of a pre-erectus hominin in Asia important. Recent research finds its wrist and foot bones to be anatomically like those of H. habilis or Australopithecus
Australopithecus
Australopithecus is a genus of hominids that is now extinct. From the evidence gathered by palaeontologists and archaeologists, it appears that the Australopithecus genus evolved in eastern Africa around 4 million years ago before spreading throughout the continent and eventually becoming extinct...

. Evidence for pre-erectus Homo in Asia would be consistent with such a possible origin.

Reflecting its status, a middle school textbook "The Chinese History" (published by People's Education Press) has been planned that includes the discovery of "Wushan Man".

Early doubts

In a Science
Science (journal)
Science is the academic journal of the American Association for the Advancement of Science and is one of the world's top scientific journals....

 report in 1995 upon the finding several doubts were raised including one by Milford Wolpoff

Milford Wolpoff of the University of Michigan, who saw the specimens on a trip to China several years ago, isn't even convinced that
the partial jaw is a hominid. "I believe it is a piece of an orangutan or other Pongo," he says. He bases that conclusion on a wear facet on the preserved premolar, which to him suggests that the missing neighboring tooth is shaped more like an orang's than a human's.p. 1117


Jeffrey Schwartz
Jeffrey H. Schwartz
Jeffrey Hugh Schwartz, PhD, is an American physical anthropologist and professor of biological anthropology at the University of Pittsburgh in Pittsburgh, Pennsylvania, President of the World Academy of Art and Science ....

 and Ian Tattersall
Ian Tattersall
Ian Tattersall is a paleoanthropologist and a curator at the American Museum of Natural History. Tattersall received his PhD from Yale University in 1971. In addition to human evolution, he has worked extensively with lemurs. He is working with The Templeton Foundation.-Selected publications:* The...

 published a claim in Nature that the teeth found in Longgupo were those of an orangutan
Orangutan
Orangutans are the only exclusively Asian genus of extant great ape. The largest living arboreal animals, they have proportionally longer arms than the other, more terrestrial, great apes. They are among the most intelligent primates and use a variety of sophisticated tools, also making sleeping...

. But the teeth are outside the range of variation of those found in orangutans ruling out this possibility.

More recently, the jaw fragment has been argued to be indistinguishable from Late Miocene
Miocene
The Miocene is a geological epoch of the Neogene Period and extends from about . The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words and and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene follows the Oligocene...

-Pliocene Chinese apes of the genus Lufengpithecus
Lufengpithecus
Lufengpithecus is a genus of extinct ape generally placed in the Ponginae subfamily.It contains three species: Lufengpithecus lufengensis, Lufengpithecus hudienensis and Lufengpithecus keiyuanensis....

. The incisor has also been argued to be consistent with that of an East Asian person that accidentally entered the deposit: "brought in by flowing water or other forces into the fissure of the comparatively old Longgupo Cave deposits".

Retraction

In 18 June 2009 issue of Nature
Nature (journal)
Nature, first published on 4 November 1869, is ranked the world's most cited interdisciplinary scientific journal by the Science Edition of the 2010 Journal Citation Reports...

, Russell Ciochon
Russell Ciochon
Russell Ciochon is an American paleoanthropologist. He was born in Altadena, California and received three degrees in anthropology from the University of California, Berkeley. He is currently a professor of anthropology at the University of Iowa...

 who first reported the jaw fragment from Longgupo as human announced that he now had changed his mind and considers that it belongs to an unknown extinct ape.

I am now convinced that the Longgupo fossil and others like it do not represent a pre-erectus human, but rather one or more mystery apes indigenous to southeast Asia’s Pleistocene primal forest. In contrast, H. erectus arrived in Asia about 1.6 million years ago, but steered clear of the forest in pursuit of grassland game. There was no pre-erectus species in southeast Asia after all.


Russell Ciochon changed his mind since he no longer believes as he did earlier that Gigantopithecus and H. erectus coexisted in the same environment--an argument he had made book in 1990 Other Origins: The Search for the Giant Ape in Human Prehistory.
Without the assumption that Gigantopithecus and H. erectus lived together, everything changed: if early humans were not part of the StegodonAiluropoda fauna, I had to envision a chimpanzee-sized ape in its place — either a descendant of Lufengpithecus, or a previously unknown ape genus.p. 911
A key factor in changing in opinion was a visit in 2005 to the Guangxi Natural History Museum in Nanning
Nanning
Nanning is the capital of the Guangxi Zhuang Autonomous Region in southern China. It is known as the "Green City" because of its abundance of lush tropical foliage.-History:...

 where he examined a large number of primate teeth from the Pleistocene. He also feels that early humans did not live in subtropic forests that existed at Longgupo at that period.

Homo erectus, it seems from this perspective, hunted grazing mammals on open grasslands, and did not or could not penetrate the dense subtropical forest.


While Russell Ciochon no longer believes the jaw to belong to a human, he still claims the two stone tools found with them were made by humans. He according to him, "They must have been more recent additions to the site".p. 911

Jeffrey Schwartz one of the critics of the original claim that the jaw was human has been quoted as noting about Ciochon's retraction that it is "really astonishing. It is not often that a scientist says he changes his mind. This openness is good."

See also

  • Peking Man
    Peking Man
    Peking Man , Homo erectus pekinensis, is an example of Homo erectus. A group of fossil specimens was discovered in 1923-27 during excavations at Zhoukoudian near Beijing , China...

  • Lantian Man
    Lantian Man
    Lantian Man , formerly Sinanthropus lantianensis is a subspecies of Homo erectus. Its discovery in 1963 was first described by J. K...

  • Tianyuan man
    Tianyuan man
    Tianyuan man are the remains of one of the earliest modern humans to inhabit eastern Asia. In 2007, researchers found 34 bone fragments belonging to a single individual at the Tianyuan Cave, near Beijing, China...

  • Yuanmou Man
    Yuanmou Man
    Yuanmou Man , Homo erectus yuanmouensis, refers to a member of the homo genus whose remnants, two incisors, were discovered near Danawu Village in Yuanmou County in southwestern province of Yunnan, China. Later, stone artifacts, pieces of animal bone showing signs of human work and ash from...

  • Zhoukoudian
    Zhoukoudian
    Zhoukoudian or Choukoutien is a cave system in Beijing, China. It has yielded many archaeological discoveries, including one of the first specimens of Homo erectus, dubbed Peking Man, and a fine assemblage of bones of the gigantic hyena Pachycrocuta brevirostris...

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK