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===Division of labor===
===Division of labor===
In 2006, anthropologists [[Steven L. Kuhn]] and [[Mary C. Stiner]] of the [[University of Arizona]] proposed a new explanation for the demise of the Neanderthals.<ref>Nicholas Wade, [http://www.nytimes.com/2006/12/05/science/05nean.html "Neanderthal Women Joined Men in the Hunt"], from ''[[The New York Times]]'', December 5, 2006</ref> In an article titled "What's a Mother to Do? The Division of Labor among Neanderthals and Modern Humans in Eurasia",<ref>Steven L. Kuhn and Mary C. Stiner, [http://www.journals.uchicago.edu/doi/abs/10.1086/507197 "What's a Mother to Do? The Division of Labor among Neandertals and Modern Humans in Eurasia"], ''Current Anthropology'', Volume 47, Number 6, December 2006</ref> they theorise that Neanderthals like [[Paleolithic#society|Middle paleolithic Homo sapiens]] did not have a [[Division of labour|division of labor]] between the sexes. Both male and female Neanderthals participated in the single main occupation of hunting big game that flourished in Europe in the ice age like bison, deer, gazelles and wild horses. This contrasted with humans who were better able to use the resources of the environment because of a division of labor with the women going after small game and gathering plant foods. In addition because big game hunting was so dangerous this made humans, at least males, more resilient (see also Peter Frost's theory on the [[Blond|origins of European blond hair]]).
In 2006, anthropologists [[Steven L. Kuhn]] and [[Mary C. Stiner]] of the [[University of Arizona]] proposed a new explanation for the demise of the Neanderthals.<ref>Nicholas Wade, [http://www.nytimes.com/2006/12/05/science/05nean.html "Neanderthal Women Joined Men in the Hunt"], from ''[[The New York Times]]'', December 5, 2006</ref> In an article titled "What's a Mother to Do? The Division of Labor among Neanderthals and Modern Humans in Eurasia",<ref>Steven L. Kuhn and Mary C. Stiner, [http://www.journals.uchicago.edu/doi/abs/10.1086/507197 "What's a Mother to Do? The Division of Labor among Neandertals and Modern Humans in Eurasia"], ''Current Anthropology'', Volume 47, Number 6, December 2006</ref> they theorise that Neanderthals like [[Paleolithic#society|Middle paleolithic Homo sapiens]] did not have a [[Division of labour|division of labor]] between the sexes. Both male and female Neanderthals participated in the single main occupation of hunting big game that flourished in Europe in the ice age like bison, deer, gazelles and wild horses. This contrasted with humans who were better able to use the resources of the environment because of a division of labor with the women going after small game and gathering plant foods. In addition because big game hunting was so dangerous this made humans, at least males, more resilient (see also Peter Frost's theory on the [[Blond#Origins|origins of European blond hair]]).


===Anatomical differences and running ability===
===Anatomical differences and running ability===

Revision as of 16:15, 30 January 2009

File:Neanderthal child.jpg
Reconstruction of a Neanderthal child from Gibraltar (Anthropological Institute, University of Zürich)

Ever since their discovery, both the Neanderthals' place in the human family tree and their relation to modern Europeans have been hotly debated. At different times they have been classified as a separate species (Homo neanderthalensis) and as a subspecies of Homo sapiens (Homo sapiens neanderthalensis).

Anthropologists advanced and still advance arguments favoring either an accelerated regional evolution of Neanderthal towards Homo Sapiens, or interbreeding with or replacement by anatomically modern humans. There is no agreement on the association of early Aurignacian culture to any specific physical human type, including figurative art found at Vogelherd.[1] The interpretation of the Neanderthal Genome Project results so far vary from a 0.1% contribution of Neanderthal to the modern gene pool, to a genetic similarity not unlike two extant members of one referenced population in West Africa.[2]

The obvious anatomic differences between Neanderthal and anatomically modern humans inspired the general belief in two separate branches of the genus Homo, and favored the single-origin hypothesis in that modern humans are not directly descended from the Neanderthal branch. The nature of interaction and dividing lines between Neanderthal and archaic Homo Sapiens during the period 50,000 to 25,000 years ago remain largely unknown.[3] Though it has been suggested that the late Neanderthal populations survived in Southern Iberia, in general this area has been considered a "cul-de-sac", playing a passive role in human/biological evolution.[4][5] There is considerable debate about whether Cro-Magnon people accelerated the demise of the Neanderthals, and many hypotheses to that extent are currently available.

Extinction scenarios

Rapid extinction

Jared Diamond has suggested a scenario of violent conflict comparable to the genocides suffered by indigenous peoples in recent human history.[6] Another possibility, paralleling colonialist history, would be a greater susceptibility to pathogens introduced by Cro-Magnon man on the part of the Neanderthals. Although Jared Diamond and others have specifically mentioned Cro-Magnon diseases as a threat to Neanderthals, this aspect of the analogy with the contacts between colonisers and indigenous peoples in recent history can be misleading.[original research?] The distinction arises because Cro-Magnons and Neanderthals are both believed probably to have lived a nomadic lifestyle,[7] [8] whereas in those genocides of the colonial era in which differential disease susceptibility was most significant, it resulted from the contact between colonists with a long history of agriculture and nomadic hunter-gatherer peoples.[original research?] Diamond argues that asymmetry in susceptibility to pathogens is a consequence of the difference in lifestyle, which makes it irrelevant in the context of the analogy in which he invokes it.

On the other hand, many Native Americans before contact with Europeans were not nomadic, but agriculturalists (Mayans, Iroquois, Cherokee), and this still did not protect them from the disease epidemics brought by Europeans (Smallpox). One theory is that because they usually lacked large domesticated animal agriculture, such as cows or pigs in close contact with people (Zoonosis), they did not develop resistance to species-jumping diseases like Europeans had. (See also Guns, Germs, and Steel.)[9]

Gradual extinction

However, these scenarios may be more drastic than is required to explain a decline of Neanderthal population over the course of some 10,000-20,000 years[citation needed]: even a slight selective advantage on the part of modern humans could account for Neanderthals' replacement on such a timescale.[citation needed] Gradual climatic change as a cause of extinction is also a common hypothesis.[citation needed] Speech-related theories have been largely discredited.[citation needed]

The problem with a gradual extinction scenario lies in the resolution of dating methods.[original research?] There have been claims for young Neanderthal sites, younger than 30,000 years old.[10] Even claims for interstratification of Neanderthal and modern human remains have been advanced.[11] So the fact that Neanderthals and modern humans coexisted at least for some time seems certain. However, because of difficulties in calibrating the C14 dates the duration of this period is uncertain.[12]

Interaction with Cro-Magnons

Interaction may have occurred at any time along the fringes of the Neanderthal expanse, and ultimately anywhere they met with the Cro Magnon advance. As for now, the expansion of the first anatomically modern humans into Europe can't be located by diagnostic and well-dated anatomically modern human fossils "west of the Iron Gates of the Danube" before 32 kya.[13] In Lagar Velho Neanderthal skeletons of younger dating have been found with mixed traits, in Southern Iberia.[14][15]

The genetic variation at the microcephalin gene, a critical regulator of brain size whose loss-of-function by damaging mutations may also cause primary microcephaly, is claimed to be the most compelling evidence of admixture thus far. One type of the gene, dubbed haplogroup D having an exceptionally high worldwide frequency (~70%), was shown to have a remarkably young coalescence age to its most recent common ancestor ~37,000 years ago. The remaining types (non-D) coalesce to ~990,000 years ago, while the separation time between D and non-D was estimated at ~1,100,000 years ago. An evolutionary advance was assumed, even though positive selection was never as all-decisive as to wipe out the remaining 30% of non-D haplogroups (in which case no introgression could have been suggested) and as for now, a measurable genetic advance has not been attested.[16] Both the worldwide frequency distribution of the D allele, exceptionally high outside of Africa but low in sub-Saharan Africa (29%) that suggests involvement of an archaic Eurasian population, and current estimates of the divergence time between modern humans and Neanderthals based on mitochondrial DNA (mtDNA), are in favor of the Neanderthal lineage as the most likely archaic Homo population from which introgression into the modern human gene pool took place. [17][18]

The case for fertile reproduction recently revived by studies that claim signs of admixture (introgression), finding unusually deep genealogies in highly divergent clades (genetic branches). However, most of the times this feature can be explained by balancing selection. For instance, estimates on the gene for red hair vary from 20,000 to 100,000 years ago[19][20], though there is no compelling evidence to assume red hair didn't coexist with other hair colours all along within one and the same population. Moreover, Lalueza-Fox and colleagues found a different variant of the same gene in their Neanderthal samples, that similarly disabled a protein to the same effect.[21]

Interbreeding

Main articles: hybrid-origin and Neanderthal Genome Project

There is another hypothesis that the Neanderthals were absorbed into the Cro-Magnon population by interbreeding. This scenario would counter the Recent African Origin scenario in favour of a hybrid-origin scenario, since it would imply that at least a minor fraction of the genome of Europeans would descend from Neanderthals, who had left Africa at least 350,000 years ago. No evidence supporting this scenario has been found in mtDNA analysis of modern Europeans, suggesting at least that no direct maternal line originating with Neanderthals has survived into modern times.[22]

The most vocal proponent of the hybridization hypothesis is Erik Trinkaus of Washington University.[23] Trinkaus claims various fossils as hybrid individuals, including the "child of Lagar Velho", a skeleton found at Lagar Velho in Portugal dated to about 24,000 years ago.[24] In a 2006 publication co-authored by Trinkaus, the fossils found in 1952 in the cave of Pestera Muierii, Romania, are likewise claimed as hybrids.[25]

Based on an Oxford University 2001 study of the gene that results in red-headedness,[26] some commentators speculated that Neanderthals had red hair and that some red-headed and freckled humans today share some heritage with Neanderthals.[27][28] A 2007 study analysing Neanderthal DNA found that some Neanderthals were indeed red-haired, but the mutation to the MC1R gene which caused red hair in Neanderthals was different from that found in modern individuals, possibly ruling out that red hair is a trait inherited from the Neanderthals.[29]

Climate change

Another hypothesis involves climate change. Although it is believed that Neanderthals had clothing[30], it has been proposed that failure to adapt their hunting methods caused their extinction when Europe changed into a sparsely vegetated steppe and half desert during the last Ice Age.[31]

Graph showing the pattern of temperature and ice volume changes associated with recent glacials and interglacials

European populations of H. neanderthalensis have been traditionally thought to be adapted to a cold environment, and thus may have had problems adapting to a warming environment.[citation needed] This may or may not be the case, although it has been suggested that the difference in cold-adaptation between Neanderthals and H. sapiens may have been minor.[citation needed]

Another possibility has to do with the loss of the Neanderthal's primary hunting territory - forests.[original research?] The Neanderthals hunted by stabbing their prey with spears (as opposed to throwing the spears at their prey).[citation needed] They were also far less mobile than modern humans.[citation needed] Thus when the forests were gradually replaced by flat lands, the Neanderthals would have had great difficulty hunting.[original research?] In the open they would not have been able to stalk their prey, their stabbing weapons would have been largely useless, and they - unlike modern humans - could not easily chase their prey. The heavily-set build of the Neanderthals also suggests that they may have had large energy requirements, therefore if their method of hunting became less efficient (as described above) the increased energy expenditure may have been too much to sustain.[original research?]

Division of labor

In 2006, anthropologists Steven L. Kuhn and Mary C. Stiner of the University of Arizona proposed a new explanation for the demise of the Neanderthals.[32] In an article titled "What's a Mother to Do? The Division of Labor among Neanderthals and Modern Humans in Eurasia",[33] they theorise that Neanderthals like Middle paleolithic Homo sapiens did not have a division of labor between the sexes. Both male and female Neanderthals participated in the single main occupation of hunting big game that flourished in Europe in the ice age like bison, deer, gazelles and wild horses. This contrasted with humans who were better able to use the resources of the environment because of a division of labor with the women going after small game and gathering plant foods. In addition because big game hunting was so dangerous this made humans, at least males, more resilient (see also Peter Frost's theory on the origins of European blond hair).

Anatomical differences and running ability

Researches including Karen L. Steudel of the University of Wisconsin have proposed that because Neanderthals had limbs that were shorter and stockier than modern humans, and because of anatomical differences in their limbs, it is theorized that the primary reason the Neanderthals were not able to survive is related to the fact that they could not run as fast as modern humans, and they would require 30% more energy than modern humans would for running or walking. [15] This would have given modern humans a huge advantage in battle. Other researchers, like Yoel Rak, from Tel-Aviv University, Israel have noted that the fossil records show that Neanderthal pelvises in comparison to modern human pelvises would have made it much harder for Neanderthals to absorb shock and to bounce off from one step to the next, giving modern humans another advantage over Neanderthals in running and walking ability. [16]

Language ability

There has also been research as to what effect any substantial difference in language ability, both physical and/or mental, between Neanderthals and modern humans could have had on the former's survival.

Main article: Neanderthals in popular culture
  • The fantasy novelist Jack Vance, in his Lyonesse Trilogy, mentions that cannibal Neanderthals battled with the ancient ancestors of the Ska, an imaginary culture or subspecies of Homo sapiens.
  • Science fiction novelist Larry Niven speculates that encounters with Neanderthals was the basis for human folklore about trolls, ogres, and suchlike.
  • Michael Crichton's novel, Next contains a series of articles describing the extinction of the apparently more intelligent Neanderthals with comparison with Homo sapiens.
  • William Golding's second novel, The Inheritors reconstructs the life of Neanderthal interaction and subsequent extinction with a "newly-evolved" malevolent Homo sapiens species.
  • The Neanderthals appear in the movie directed by Shawn Levy "Night at the Museum". They are however incorrectly depicted as a species that lacked complex language, and couldn't control fire.
  • The Neanderthal Parallax - a trilogy of novels by Robert J. Sawyer - shows the effects of the opening of a connection between two alternate Earths: the world familiar to the reader, and another where Neanderthals became the dominant, sentient hominid. The societal, spiritual and technological differences between the two worlds form the focus of the story.
  • Jasper Fforde's novel, Lost in a Good Book contains many clones of extinct animals. It also features cloned Neanderthals, who are treated as subhuman, but who actually are very peace-loving and cultured.

Notes

  1. ^ Conard, N.J. et al. (2004) Unexpectedly recent dates for human remains from Vogelherd. Nature 430, 198–201 [1]; [2]
  2. ^ [3] Inconsistencies in Neanderthal Genomic DNA Sequences - Jeffrey D. Wall & Sung K. Kim, published October 12, 2007 at PLOS Genetics;[4] Analysis of one million base pairs of Neanderthal DNA - Richard E. Green et al, Nature 444, 330-336, 16 November 2006;[5] Sequencing and Analysis of Neanderthal Genomic DNA - James P. Noonan et al, Science 17 November 2006: Vol. 314. no. 5802, pp. 1113 - 1118
  3. ^ [6] Rapid ecological turnover and its impact on Neanderthal and other human populations - Clive Finlayson and Jose´ S. Carrión, Trends in Ecology & Evolution, Volume 22, Issue 4 , April 2007, Pages 213-222
  4. ^ Climate forcing and Neanderthal extinction in Southern Iberia: insights from a multiproxy marine record - Francisco J. Jiménez-Espejo, Quaternary Science Reviews, Volume 26, Issues 7-8, April 2007, Pages 836-852, Elsevier Ltd
  5. ^ European early modern humans and the fate of the Neandertals Erik Trinkaus; doi: 10.1073/pnas.0702214104 PNAS May 1, 2007 vol. 104 no. 18 7367-7372
  6. ^ Diamond, Jared (1992), The Third Chimpanzee: The Evolution and Future of the Human Animal, Harper Perennial, ISBN 0060984031
  7. ^ Prideaux, Tom (1979), Cro-Magnon Man, Time-Life Books, ISBN 0705400557
  8. ^ Lewin, Roger (1999), Human Evolution: An Illustrated Introduction, Blackwell, ISBN 0632043091
  9. ^ The Evolution of Germs
  10. ^ Finlayson, C., F. G. Pacheco, J. Rodriguez-Vidal, D. A. Fa, J. M. G. Lopez, A. S. Perez, G. Finlayson, E. Allue, J. B. Preysler, I. Caceres, J. S. Carrion, Y. F. Jalvo, C. P. Gleed-Owen, F. J. J. Espejo, P. Lopez, J. A. L. Saez, J. A. R. Cantal, A. S. Marco, F. G. Guzman, K. Brown, N. Fuentes, C. A. Valarino, A. Villalpando, C. B. Stringer, F. M. Ruiz, and T. Sakamoto. 2006. Late survival of Neanderthals at the southernmost extreme of Europe. Nature advanced online publication.
  11. ^ Gravina, B., P. Mellars, and C. B. Ramsey. 2005. Radiocarbon dating of interstratified Neanderthal and early modern human occupations at the Chatelperronian type-site. Nature 438:51-56.
  12. ^ Mellars, P. 2006. A new radiocarbon revolution and the dispersal of modern humans in Eurasia. Nature' 439:931-935.
  13. ^ Trinkaus, E. (2005) Early modern humans. Annu. Rev. Anthropol. 34, 207–230 [7]
  14. ^ The early Upper Paleolithic human skeleton from the Abrigo do Lagar Velho (Portugal) and modern human emergence in Iberia - Cidália Duarte, João Maurício, Paul B. Pettitt, Pedro Souto, Erik Trinkaus, Hans van der Plicht, and João Zilhão, PNAS Vol. 96, Issue 13, 7604-7609, June 22, 1999 [8]
  15. ^ [9]
  16. ^ Mekel-Bobrov, N.; et al. (2007). "The ongoing adaptive evolution of ASPM and Microcephalin is not explained by increased intelligence". Hum. Mol. Genet. 16: adv. access. doi:10.1093/hmg/ddl487. PMID 17220170. {{cite journal}}: Explicit use of et al. in: |author= (help)
  17. ^ Evans, Patrick D. (2006-11-07). "Evidence that the adaptive allele of the brain size gene microcephalin introgressed into Homo sapiens from an archaic Homo lineage". PNAS. 10 (48): 18178–18183. doi:10.1073/pnas.0606966103. PMID 17090677. Retrieved 2008-05-26. {{cite journal}}: Check date values in: |date= (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)
  18. ^ Evans, Patrick D. (2005-09-09). "Microcephalin, a Gene Regulating Brain Size, Continues to Evolve Adaptively in Humans". Science. 309 (5741): 1717–1720. doi:10.1126/science.1113722. PMID 16151009. {{cite journal}}: Check date values in: |date= (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)
  19. ^ Nicole's hair secrets Daily Telegraph 2002-10-02, Accessed 2005-11-02
  20. ^ Red hair genes 100,000 years old Oxford Blueprint Vol. 1 Issue 11 2001-05-31
  21. ^ [10] A Melanocortin 1 Receptor Allele Suggests Varying Pigmentation Among Neanderthals - Carles Lalueza-Fox et al., Science. 2007 Oct 25
  22. ^ Krings et al., Neandertal DNA sequences and the origin of modern humans Cell. 1997 Jul 11;90(1):19-30. Deborah Hill, [11]; No Neandertals in the Gene Pool, Science (2004).
  23. ^ Dan Jones: The Neanderthal within., New Scientist 193.2007, H. 2593 (3 March), 28–32. Modern Humans, Neanderthals May Have Interbred; Humans and Neanderthals interbred
  24. ^ [12]; [13]; [14]
  25. ^ Andrei Soficaru u. a.: Early modern humans from Pestera Muierii, Baia de Fier, Romania. in: Proceedings of the National Academy of Sciences. Washington 2006.
  26. ^ Red hair a legacy of Neanderthal man
  27. ^ "Red-Heads and Neanderthals". May 2001. Retrieved 2005-10-28.
  28. ^ "Nicole's hair secrets". 2002-02-10. Retrieved 2005-11-02.
  29. ^ Paul Rincon, Neanderthals 'were flame-haired' BBC 25 October 2007.
  30. ^ Gilligan, I: "Neanderthal extinction and modern human behaviour: the role of climate change and clothing", World Archaeology, Vol. 39, No. 4. (2007), pp. 499-514.
  31. ^ Climate Change Killed Neandertals, Study Says, National Geographic News
  32. ^ Nicholas Wade, "Neanderthal Women Joined Men in the Hunt", from The New York Times, December 5, 2006
  33. ^ Steven L. Kuhn and Mary C. Stiner, "What's a Mother to Do? The Division of Labor among Neandertals and Modern Humans in Eurasia", Current Anthropology, Volume 47, Number 6, December 2006

References

See also

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