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Homo sapiens

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Homo sapiens
Temporal range: 0.3–0 Ma
↓
 Middle Pleistocene–Present
Akha man and woman in northern Thailand – husband carries stem of banana-plant, which will be fed to their pigs
Male and female H s. sapiens
(Akha in northern Thailand,
2010 photograph)
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Primates
Suborder: Haplorhini
Infraorder: Simiiformes
Family: Hominidae
Subfamily: Homininae
Tribe: Hominini
Genus: Homo
Species:
H. sapiens
Binomial name
Homo sapiens
Linnaeus, 1758
Subspecies

H. s. sapiens
†H. s. idaltu
†H. s. neanderthalensis(?)
†H. s. rhodesiensis(?)
(others proposed)

Humans are the only living species of the genus Homo. Homo is the human genus. H. sapiens is the only surviving species of the genus Homo. Homo sapiens are sometimes called "anatomically modern humans".

Origin

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See the main article: Out of Africa
Schematic representation of the emergence of H. sapiens from earlier species of Homo. The horizontal axis shows geographic location; the vertical axis shows time in millions of years ago.
Blue areas show presence at a given time and place.[2]

The recent African origin of modern humans is the mainstream model of the origin and dispersal of anatomically modern humans.[3]

The hypothesis that humans have a single origin was published in Charles Darwin's The Descent of Man (1871). The concept is supported by a study of present-day mitochondrial DNA, and with evidence based on physical anthropology of fossil humans. According to genetic and fossil evidence, older versions of Homo sapiens evolved only in Africa, between 200,000 and 100,000 years ago, with members of one branch leaving Africa by 90,000 years ago and over time replacing earlier human populations such as Neanderthals and Homo erectus.

The recent single origin of modern humans in East Africa is the near-consensus position held within the scientific community.[4][5][6][7][8]

Sequencing of the full Neanderthal genome suggests Neanderthals and some modern humans share some ancient genetic lineages. The authors of the study suggest that their findings are consistent with Neanderthal admixture of up to 4% in some populations. The reason for this admixture is not known.[9] In August 2012, a study suggested that the DNA overlap is a remnant of a common ancestor of both Neanderthals and modern humans.[10][11]

Evolution

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Further information: Human evolution

The time frame for the evolution of the genus Homo out of the last common ancestor is roughly 10 to 2 million years ago, that of H. sapiens out of Homo erectus roughly 1.8 to 0.2 million years ago.

Scientific study of human evolution is mostly concerned with the development of the genus Homo, but usually involves studying other hominids and hominines as well, such as Australopithecus. "Modern humans" are defined as the Homo sapiens species, of which the only living subspecies is known as Homo sapiens sapiens.

Homo sapiens idaltu, the other known subspecies, is now extinct.[12] Homo neanderthalensis, which became extinct 30,000 years ago, has sometimes been classified as a subspecies, "Homo sapiens neanderthalensis". Genetic studies now suggest that the functional DNA of modern humans and Neanderthals diverged 500,000 years ago.[13]

Similarly, the discovered specimens of the Homo rhodesiensis species have been classified by some as a subspecies, but this classification is not widely accepted.

Earliest fossils of the species

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Until recently it was thought that anatomically modern humans first appeared in the fossil record in Africa about 195,000 years ago. Studies of molecular biology suggested that the approximate time of divergence from the common ancestor of all modern human populations was 200,000 years ago.[14][15][16][17][18] The broad study of African genetic diversity found the ǂKhomani San people had the greatest genetic diversity among the 113 distinct populations sampled, making them one of 14 "ancestral population clusters". The research also placed the origin of modern human migration in south-western Africa, near the coastal border of Namibia and Angola.[19][20]

In the 1960s an archaeological site at Jebel Irhoud in Morocco was dated as about 40,000 years old but it was re-dated in the 2000s. It is now thought to be between 300,000 and 350,000 years old. The skull form is almost identical to modern humans,[21] though the jaw is different.

The forces of natural selection have continued to operate on human populations, with evidence that certain regions of the genome show selection in the past 15,000 years.[22]

References

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  1. ↑ Global Mammal Assessment Team (2008). "Homo sapiens". The IUCN Red List of Threatened Species. 2008. IUCN: e.T136584A4313662. doi:10.2305/IUCN.UK.2008.RLTS.T136584A4313662.en. Archived from the original on 7 December 2017. Retrieved 12 January 2018.
  2. ↑ Stringer, C. (2012). "What makes a modern human". Nature. 485 (7396): 33–35. doi:10.1038/485033a. PMID 22552077. S2CID 4420496.
  3. ↑ Wood B. 2010. Reconstructing human evolution: achievements, challenges, and opportunities. Proceedings of the National Academy of Sciences 107: 8902–8909. [1]
  4. ↑ Liu, Hua; Prugnolle, Franck; Manica, Andrea; Balloux, François (2006). "A Geographically Explicit Genetic Model of Worldwide Human-Settlement History". The American Journal of Human Genetics. 79 (2): 230–237. doi:10.1086/505436. PMC 1559480. PMID 16826514.
  5. ↑ "Out of Africa revisited - Science 308 (5724): 921g -". Sciencemag.org. 2005-05-13. doi:10.1126/science.308.5724.921g. S2CID 220100436. Retrieved 2009-11-23. {{cite journal}}: Cite journal requires |journal= (help)
  6. ↑ Nature (2003-06-12). "Access: human evolution: out of Ethiopia". Nature. 423 (6941): 693–695. doi:10.1038/423692a. PMID 12802315. S2CID 26693109. Retrieved 2009-11-23.
  7. ↑ "Origins of modern humans: multiregional or out of Africa?". ActionBioscience. Archived from the original on 2010-11-22. Retrieved 2009-11-23.
  8. ↑ "Modern humans - single origin (out of Africa) vs multiregional". Asa3.org. Retrieved 2009-11-23.
  9. ↑ Green R.E.; et al. (2010). "A draft sequence of the Neanderthal genome". Science. 328 (5979). Science (journal): 710–22. Bibcode:2010Sci...328..710G. doi:10.1126/science.1188021. PMC 5100745. PMID 20448178.
  10. ↑ Study casts doubt on human-Neanderthal interbreeding theory, The Guardian, Tuesday 14 August 2012
  11. ↑ Anders Eriksson and Andrea Manica Effect of ancient population structure on the degree of polymorphism shared between modern human populations and ancient hominins PNAS 2012 : 1200567109v1-201200567. July 20, 2012
  12. ↑ Human evolution: the fossil evidence in 3D, by Philip L. Walker and Edward H. Hagen, Dept. of Anthropology, University of California, Santa Barbara. Retrieved April 5, 2005.
  13. ↑ Green R.E.; et al. (2006). "Analysis of one million base pairs of Neanderthal DNA". Nature. 444 (7117): 16, 330–336. Bibcode:2006Natur.444..330G. doi:10.1038/nature05336. PMID 17108958. S2CID 4320907.
  14. ↑ nsf.gov - National Science Foundation (NSF) News - New clues add 40,000 years to age of human species - US National Science Foundation (NSF)
  15. ↑ "Age of ancient humans reassessed". BBC News. February 16, 2005. Retrieved April 10, 2010.
  16. ↑ The oldest Homo sapiens: – URL retrieved May 15, 2009
  17. ↑ Alemseged, Z., Coppens, Y., Geraads, D. (2002). "Hominid cranium from Homo: description and taxonomy of Homo-323-1976-896". Am J Phys Anthropol. 117 (2): 103–12. doi:10.1002/ajpa.10032. PMID 11815945.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  18. ↑ Stoneking, Mark; Soodyall, Himla (1996). "Human evolution and the mitochondrial genome". Current Opinion in Genetics & Development. 6 (6): 731–6. doi:10.1016/S0959-437X(96)80028-1. PMID 8994844.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  19. ↑ Henn, Brenna; Gignoux, Christopher R.; Jobin, Matthew (2011). "Hunter-gatherer genomic diversity suggests a southern African origin for modern humans". Proceedings of the National Academy of Sciences of the United States of America. 108 (13). National Academy of Sciences: 5154–62. doi:10.1073/pnas.1017511108. PMC 3069156. PMID 21383195.
  20. ↑ Gill, Victoria (May 1, 2009). "Africa's genetic secrets unlocked". BBC News.; the results were published in the online edition of the journal Science.
  21. ↑ Ghosh P. 2017. First of our kind found in Morocco. BBC News Science & Environment. [2]
  22. ↑ Wade, N (2006-03-07). "Still evolving, human genes tell new story". The New York Times. Retrieved 2008-07-10.

22. Homo sapiens https://aboutsoul.in/Homo%20sapiens-2304[permanent dead link]Homo sapiens, a term derived from Latin meaning "wise man," represents the species to which all modern human beings belong.

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