Red Deer Cave people

The Red Deer Cave people were the most recent known prehistoric archaic human population. Fossils dated to the Bølling-Allerød warming, between about 14,500 to c. 11,500 years ago, were found in Red Deer Cave (Maludong) and Longlin Cave in Southwest China.

Longlin 1, a partial skull

The fossils exhibit a mix of archaic and modern features and are tentatively thought to represent a late survival of an archaic human species, or of a hybrid population of Denisovan hominin and modern human descent, or alternatively just "robust early modern humans, probably with affinities to modern Melanesians".[1][2]

Evidence shows large deer were cooked in the Red Deer Cave, giving the people their name.[3]

Discovery and dating

Mandibles

In 1979, the partial skull of a cave dweller was found in Longlin Cave in the Guangxi region of China. Additional human remains were excavated from Maludong ("Red Deer Cave"; Chinese: 马鹿洞), Yunnan Province, in 1989.

In 2012, the Red Deer Cave fossils were indirectly radiocarbon dated between 14,300 and 12,600 years before present, using charcoal found in the fossil deposits. The single Longlin fossil was dated to 11,500 years before present (mean calibrated age 11,510±255 95% CI).[4]

The partial thighbone discovered in Maludong (meaning Red Deer Cave) in 1989 and the partial jaw, cranial bones, and teeth. The dating of the bones has led to confusion and division among researchers. The anatomy of the bones, without successful DNA testing, shows them to be archaic humans, like early Homo erectus or Homo habilis which lived around 1.5 million years ago in Africa.[5] Researcher Darren Curnoe believes that the cave people were a new evolutionary line. This is because of the skulls are different from both modern humans and human skulls found in Africa dating back 150,000 years.[6] From the thighbone analysis, it is believed that they roamed the same landscape as modern humans for 60,000 years.[7]

Anatomy

In spite of their relatively recent age, the fossils exhibit archaic human features.[8] The Red Deer Cave dwellers had distinctive features that differ from modern humans, including: flat face, broad nose, jutting jaw with no chin, large molars, prominent brows, thick skull bones, and moderate-size brain.[1] As other pre-modern humans, their body size was small, with an estimated mass of 50 kg (110 lb).[9]

From the shape of the thighbone, it is believed the Red Deer Cave People may have been knock-kneed.[10] Curnoe's previous works showed the bones and teeth were remarkably similar to that of archaic humans.[11] This is despite them having lived only between 14,000 and 11,000 years ago.[12] The reconstruction of the Maludong femur confirmed it was very small and the outer shell or walls being very thin. The areas of the wall that were of high strain the femur neck are long and the place of muscle attachment for the primary flexor muscle of the hip (the lesser trochanter) is very large and faces strongly backward.[13]

Classification

Experts are reluctant to classify the Red Deer Cave people as a new species.[1] They might represent a previously unknown archaic human lineage, or the result of mating between Denisovans and modern humans,[3] or alternatively a thoroughly anatomically modern human population with unusual physiology.[1] However, research shows the Red Deer Cave people appear similar to more archaic lineages such as Homo erectus or Homo habilis.[9] Specifically, the specimen appears most similar in most of the characteristics to KNM-ER 1481,[8] Homo Erectus from 1.89 Mya found in Africa.[14] Others have noted similarities to Australopithecus (taken to mean beyond Homo, ed.).[15] Attempts to isolate ancient DNA from the fossils have not been successful.[16]

One theory suggests that the Red Deer Cave people were early humans that settled into the region more than a 100,000 years ago and became isolated.[17] The high mountains and deep valleys are ideal in isolating species geographically, so it is possible for a species to migrate to the area and become isolated over time. The environment and climate of Southwest China are unique owing to the tectonic uplift of the Qinghai-Tibetan Plateau. The Yunnan province still has today some of the greatest biodiversity in all of China.

Since no DNA has successfully been extracted from the bones yet, the research that has been done is also leading the conclusion that the Deer Cave People can be the result of being a hybrid with modern humans. Another theory that has been stated by Maciej Henneberg, a professor at the University of Adelaide and an expert in human anatomy, is that the bone is not primate at all. It may be a deer's femur that has degraded to the point it was misidentified.      

See also

References

  1. Owen J (2012-03-14). "Cave Fossil Find: New Human Species or "Nothing Extraordinary"?". National Geographic News.
  2. Curnoe D, Ji X, Taçon PS, Yaozheng G (July 2015). "Possible Signatures of Hominin Hybridization from the Early Holocene of Southwest China". Scientific Reports. 5 (1): 12408. Bibcode:2015NatSR...512408C. doi:10.1038/srep12408. PMC 5378881. PMID 26202835.
  3. Barras C (2012-03-14). "Chinese human fossils unlike any known species". New Scientist. Retrieved 2012-03-15.
  4. Curnoe D, Xueping J, Herries AI, Kanning B, Taçon PS, Zhende B, et al. (2012). Caramelli D (ed.). "Human remains from the Pleistocene-Holocene transition of southwest China suggest a complex evolutionary history for East Asians". PLOS ONE. 7 (3): e31918. Bibcode:2012PLoSO...731918C. doi:10.1371/journal.pone.0031918. PMC 3303470. PMID 22431968. All of the [Maludong] human remains were recovered from within a series of deposits dating from 14,310±340 cal. yr BP (OZM149; 292 cm depth) to 13,590±160 cal. yr BP (OZM145; 166 cm depth), a period of about 720 years. Moreover, the high fine-grained ferrimagnetic content of the deposits (Text S1), with their high magnetic susceptibility, suggests these were formed under warm, wet conditions, consistent with the Bølling-Allerød interstadial (∼14.7-12.6 ka). Human remains recovered in situ during the 2008 excavation and a reasonably complete calotte (specimen MLDG 1704) derived from a subsection of these deposits dated between 13,990±165 cal. yr BP (OZM148; 235 cm) and 13,890±140 cal. yr BP (OZM146; 200 cm)
  5. Curnoe, Darren; Ji, Xueping; Liu, Wu; Bao, Zhende; Taçon, Paul S. C.; Ren, Liang (2015-12-17). "A Hominin Femur with Archaic Affinities from the Late Pleistocene of Southwest China". PLOS ONE. 10 (12): e0143332. doi:10.1371/journal.pone.0143332. ISSN 1932-6203. PMC 4683062. PMID 26678851.
  6. Hellstrom, John. "Further geological and palaeoanthropological investigations at the Maludong hominin site, Yunnan Province, Southwest China". Cite journal requires |journal= (help)
  7. Lea, Seán. "The genetic legacy of archaic hominin species". Cite journal requires |journal= (help)
  8. Curnoe D, Ji X, Liu W, Bao Z, Taçon PS, Ren L (17 December 2015). "A Hominin Femur with Archaic Affinities from the Late Pleistocene of Southwest China". PLOS ONE. 10 (12): e0143332. Bibcode:2015PLoSO..1043332C. doi:10.1371/journal.pone.0143332. PMC 4683062. PMID 26678851.
  9. Curnoe D. "Bone Suggests 'Red Deer Cave People' A Mysterious Species Of Human". IFLScience. Retrieved 2019-01-27.
  10. Lea, Seán. "The genetic legacy of archaic hominin species". Cite journal requires |journal= (help)
  11. Curnoe, Darren; Ji, Xueping; Liu, Wu; Bao, Zhende; Taçon, Paul S. C.; Ren, Liang (2015-12-17). "A Hominin Femur with Archaic Affinities from the Late Pleistocene of Southwest China". PLOS ONE. 10 (12): e0143332. doi:10.1371/journal.pone.0143332. ISSN 1932-6203. PMC 4683062. PMID 26678851.
  12. Curnoe, Darren; Ji, Xueping; Liu, Wu; Bao, Zhende; Taçon, Paul S. C.; Ren, Liang (2015-12-17). "A Hominin Femur with Archaic Affinities from the Late Pleistocene of Southwest China". PLOS ONE. 10 (12): e0143332. doi:10.1371/journal.pone.0143332. ISSN 1932-6203. PMC 4683062. PMID 26678851.
  13. Curnoe, Darren; Ji, Xueping; Liu, Wu; Bao, Zhende; Taçon, Paul S. C.; Ren, Liang (2015-12-17). "A Hominin Femur with Archaic Affinities from the Late Pleistocene of Southwest China". PLOS ONE. 10 (12): e0143332. doi:10.1371/journal.pone.0143332. ISSN 1932-6203. PMC 4683062. PMID 26678851.
  14. "KNM-ER 1481". The Smithsonian Institution's Human Origins Program. 2010-01-21. Retrieved 2019-10-27.
  15. Schwartz J (June 2016). "What constitutes Homo sapiens? Morphology versus received wisdom". Journal of Anthropological Sciences = Rivista Di Antropologia. 94 (94): 65–80. doi:10.4436/JASS.94028. PMID 26963221.
  16. "Red Deer Cave thigh bone suggests prehistoric humans survived until recently". CBC News. 21 December 2015.
  17. Curnoe, Darren. "Bone suggests 'Red Deer Cave people' a mysterious species of human". The Conversation. Retrieved 2020-05-29.
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