The Neanderthals were a species or subspecies of archaic humans in the genus Homo. They lived in Europe and Western Asia, with a fossil record roughly dating from between 350,000 and 40,000 years ago.
Intelligence and disappearance
The Neanderthals had on average a somewhat larger brain than the modern humans. One explanation for this is greater lean body mass, which may have required more neural tissue involved in body maintenance and control. Another explanation is that the Neanderthals had large eye orbits, which may indicate large brain areas dedicated to visual abilities. Such an association is found in other primates, with one explanation being that this is an adaptation to the lower light levels in northern regions.
One explanation for the disappearance of the Neanderthals is that they had higher physical robustness and higher visual abilities (and larger brain areas dedicated to these abilities), but lower social abilities, which would cause problems such as lowered ability to acquire and conserve innovations.
This is somewhat similar to the commonly stated explanation for the disappearance of the Neanderthals, which is that they were outcompeted by the more intelligent modern humans. This has been argued to be incorrect and there being no support for the supposed technological, social, and cognitive inferiority of Neanderthals. A more likely explanation for the disappearance is argued to be factors such as interbreeding with anatomically modern humans, a low population size, and "genetic swamping and assimilation by the increasing numbers of modern immigrants."
A 2020 study stated that "the idea that Neanderthals were cognitively inferior to modern humans is becoming increasingly untenable."
Other disappearance theories
There are also various other theories regarding the disappearance, such as climate changes, the Neanderthals being outcompeted due to the Neanderthals not having a division of labor between the sexes, the Neanderthals not having the domesticated dog, the Neanderthals being poorer runners, and/or the Neanderthals having poorer immune system (in particular against pathogens from Africa introduced by anatomically modern human immigrants).
Effects of the interbreeding
Several percent of the genomes of the human populations outside of Africa are estimated to be of Neanderthal origin. Neanderthal genetic contributions may have played important roles in the development of the immune system and in UV-light adaptations.
Different non-African populations may have differences regarding Neanderthal genetic influence. For example, a 2013 study found varying frequencies in different populations of a gene variant that appears to have been inherited from Neanderthals and that is associated with differences regarding diabetes risk. Another example is the H2 haplotype [of the MAPT gene] that is derived from Neanderthals and only present in Caucasoids.
A 2017 study found that a higher degree of Neanderthal-originating genetics in modern humans is associated with having a skull shape having a higher degree similarity with Neanderthal skull shape. Furthermore, this was associated with the shape of different brain regions and the study suggested that "Neanderthal-derived genetic variation is neurologically functional in the contemporary population."
- "Indeed, the present-day European skulls resemble Neanderthal skulls more closely than they resemble the skulls of American Indians or Australian aborigines." - "Neanderthal Traits Extant, Group Told" The Arizona Republic (Phoenix) Nov 20, 1988, p. B-5 reporting on C. Loring Brace, Physical anthropologist.
- Neandertal Demise: An Archaeological Analysis of the Modern Human Superiority Complex
- Direct evidence of Neanderthal fibre technology and its cognitive and behavioral implications
- Villa P, Roebroeks W (2014) Neandertal Demise: An Archaeological Analysis of the Modern Human Superiority Complex. PLoS ONE 9(4): e96424. doi:10.1371/journal.pone.0096424 http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0096424
- Pearce E, Stringer C, Dunbar RI (2013) New insights into differences in brain organization between Neanderthals and anatomically modern humans. Proc Biol Sci 280 (1758):20130168. http://dx.doi.org/10.1098/rspb.2013.0168 http://pubmed.gov/23486442
- Direct evidence of Neanderthal fibre technology and its cognitive and behavioral implications https://www.nature.com/articles/s41598-020-61839-w
- Diabetes risk gene 'from Neanderthals'. 25 December 2013 Last updated at 18:27. BBC. http://www.bbc.co.uk/news/science-environment-25506198
- Hardy J, Pittman A, Myers A, Gwinn-Hardy K, Fung HC, de Silva R et al. (2005) Evidence suggesting that Homo neanderthalensis contributed the H2 MAPT haplotype to Homo sapiens. Biochem Soc Trans 33 (Pt 4):582-5. http://dx.doi.org/10.1042/BST0330582 http://pubmed.gov/16042549
- Neanderthal-Derived Genetic Variation Shapes Modern Human Cranium and Brain https://www.nature.com/articles/s41598-017-06587-0