It is assumed that early Europeans were derived exclusively from the middle Paleolithic modern humans, expanding through southwestern Asia and then westward across Europe at about 41 000 years ago. However, there are numerous craniofacial, dental, and postcranial traits in European early humans that are unlikely to have come from middle Paleolithic modern humans; many of these traits are distinctly Neanderthal.

By Bernie Douglas (April 11, 2008), Revised February 17, 2009

Evolution or Interbreeding?

Many noted paleoanthropological researchers currently argue that modern Europeans may share close biological relationships with archaic Neanderthal man (Brace, 1979, 2004; Wolpoff et al, 2004; Trinkaus, 2007; Gutiérrez and Sánchez, 2002). Evidence comes from craniofacial measurements used to compare hominid species. This research shows that nuances relating to the cranial outlines of European Neanderthals are identical to the nuances observed in modern Europeans (Brace, 2005; Brace, 1979; Trinkaus, 2007). Morphological differences between these two populations are said to exist primarily with respect to facial form (Brace, 2005).

One theory purposes that such facial morphological differences may have come as the result of a reduction in tooth size that took place over a period of thousands of years (Brace, 1979; 2005).  For example, the Krapina Neanderthals at the end of the last interglacial differed from Homo erectus only in having larger front teeth, while “Classic” Neanderthals of Western Europe had teeth that are 15% smaller than those of the earlier Krapina Neanderthals and only 5% larger than early Upper Paleolithic Neanderthals. It is these incremental reductions in tooth size, along with their resulting changes in craniofacial form which are believed, “by some”, to reflect an (in situ) evolution of modern European facial form from an ancestral Neanderthal one (Brace, 1979 2005). While this theory represents a rather extreme position, other more widely accepted theories argue simply that early Europeans may have interbred with Neanderthals at rates great enough that Neanderthal features can still be observed in modern, particularly ‘northwestern European’ populations, today (Tinkaus, 2007; Wolpoff et al, 2004).    

A number of molecular genetic studies have attempted to use ancient Neanderthal mtDNA (mitochondrial DNA) to investigate the possibility of whether Europeans today really do possess an ancient Neanderthal genetic heritage (Caramelli, 2003; Ovchinnikov, 2000). However, problems lay in the use of Mitochondrial DNA (mtDNA), as it is genetic material that lies outside the nucleus of the cell, and thus can only provide limited biological information. Genetic researchers have not been able to use Neanderthal nDNA to determine a possible contribution to modern European gene pool. Nuclear deoxyribonucleic acid (nDNA) is DNA contained within a nucleus of eukaryotic organisms. In most cases it encodes more of the genome than mitochondrial DNA (mtDNA) and is passed sexually rather than maternally. Nuclear DNA is also the most common DNA used in forensic examinations. Molecular Genetic researchers argue that mtDNA studies do not take into account the high substitution rate variation among sites observed in the human mitochondrial D-loop region; and that they lack an estimation of the parameters of the nucleotide substitution model (Gutiérrez and Sánchez, 2002). In the absence of Neanderthal autosomal nDNA sequences as well Y-chromosomal information, the assessment of human- Neanderthal admixture remains a tentative matter.

Evidence of a European/Neanderthal Connection:

Some have in the past denied the existence of Neanderthal characteristics in certain Cro-Magnon remains (early modern Europeans) and consider them anatomically modern (Hublin, Tillier, and tixier 1987), while others have pointed to the presence of occipital bunning in some remains (Ennouchi, 1962; Brace 2005) as indicating specifically European Neanderthal influences (Simmons, 1990; Brace, 2005). Among archaic humans in the western old world, bunning has been documented only in Europe, where it is extremely common among Neanderthals (Simmons and Smith, 1991). Bunning is not characteristic of other representatives of the African transitional group or the earliest “modern” African specimens (Simmons and Smith, 1991). Bunning is also not a characteristic feature of other broadly contemporaneous hominids in western Asia and Africa. Some evolutionary researchers believe that this is exactly what one would expect if Neanderthal form simply evolved into "modern" European form, in situ (Brace, 2005).

While the morphological aspects of the earliest modern humans in Europe (more than 33,000 B.P.) indicate that they do in fact possess an anatomical pattern largely inline with the morphology of the earliest (Middle Paleolithic) African modern humans; they also exhibit features that are distinctively Neanderthal (see Trinkaus, 2007). For example, numerous craniofacial, dental, and postcranial traits in European early humans are unlikely to have come from middle Paleolithic modern humans, and have been argued to be Neanderthal in origin (Trinkaus, 2007). If associated admixture between Europeans were rare or non existent, one would expect only to find a few of these non early modern human traits in a few European early modern humans; however, this is not the case (Trinkaus, 2007; Brace, 2005; Wolpoff, 2004)!

In short, European populations may reflect both their predominant African early modern human ancestry and a substantial degree of admixture between those early modern humans and the indigenous European Neanderthals (Trinkaus, 2007; Wolpoff, 2004). According to Trinkaus (2007), given the tens of thousands of years since then and the limitations inherent in ancient DNA, this process is largely invisible in the molecular mtDNA record. However, it is still highly apparent in the paleontological record (Trinkaus, 2007). Others still, believe that Europeans may have simply evolved from an ancestral Neanderthal form, in situ (Brace, 2005; Brace, 1979).

Who were the Neanderthals?

Neanderthals originated about 300,000 years ago and occupied much of Europe and West Asia by up to 200,000 years ago. They survived as a species for longer than modern humans have existed until suddenly going extinct shortly after the first appearance of modern humans (Horan et al, 2005; Mellars, 2004). Neanderthal behavior has been described as “inflexible” (Mithen 1998), and as “imitators” rather than innovators (Kuhn and Stiner 1998). Research has also shown that Neanderthal technologies did not advance significantly over their reign, and it appears the exchange of knowledge and ideas through social interaction were limited (Kuhn and Stiner 1998).

Neanderthals never developed trade links with other Neanderthal groups (Gee 1996, p.36), and their social group sizes were limited, consisting of about two dozen individuals at most. Their living spaces were largely unorganized, with no evidence that the spaces were divided according to different functions (Tattersall and Schwartz 2000), as seen in lower primate species, today. Neanderthal sites lacked the structure and complexity of those of early modern humans. It is generally believed that Neanderthals also lacked complex social organization, a degree of innovative behavior, forward planning, and the exchange of information, ideas, and raw materials (Horan et al, 2005).

Unlike Neanderthals, early humans exhibited complex living arrangements in which different sections of the living areas were partitioned for different functions. Moreover, compared to Neanderthals, early humans developed significantly more types of activities with more detailed workmanship, they imported more raw materials, and they generated more innovations that were dispersed more widely (Tattersall and Scwartz 2000; Blades 2001; Kuhn and Stiner 1998). Tattersall and Schwartz (2000, p.212) indicate that there is little evidence to refute the notion that the Neanderthal’s lacked modern human levels of forward planning and anticipation.

Do Africans have any admixture?

Some researchers believe that Africans in general and West Africans in particular may possess ancient admixture with Qafzeh man (Brace, 1995, 1996; Qintyne 2006).  Often credited as being proto modern European, the fossil records at Qafzeh and other sites in the Middle East are significant to the story of the origins of modern humans. Finds from these sites are decidedly "modern" (i.e. Homo sapien sapiens).

In the book “The Morphometric Affinities of the Qafzeh and Skhul Hominans: Method and Theory” (Qintyne, 2006), Qafzeh is found to tie in with African and Levantine (Middle Eastern) sample groups, and not with ancient Europeans. Brace (1995, 1996) finds that Qafzeh ties in more closely with West African samples and not with Europeans, while he believes Neanderthals share close affinities with European samples. For example, Brace finds that the proportions of incisor to molar dimensions of modern Europeans are exactly the same as the Neanderthal proportions, but radically different than African front to back tooth proportions; while Qafzeh proportions are exactly the same as modern West African proportions, only markedly larger (1995, 1996). Some also believe Asians may possess admixture with Peking man.

It should be kept in mind that virtually all research finds that Homo sapiens are a separate species from Neanderthals, and that all living humans today are Homo sapiens (see Alan, 2003).

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