Genomic Data Reveal a Complex Making of Humans Sept 21, 2013 20:49:18 GMT
Post by Admin on Sept 21, 2013 20:49:18 GMT
Europeans and Asians have inherited 1-5% of Neanderthal DNA as Homo sapiens out of Africa interbred with the Neanderthals in the Mediterranean around 60,000 years ago, which gave rise to the IQ gap between non-Africans and Africans with no Neanderthal admixture. Neanderthal cranial capacity was slightly larger than that of modern humans and they invented stone tools known as 'flakes', which were more efficient than the blades adopted by Homo sapiens, and the Neanderthals had more sophisticated Stone Age culture than AMHs who had just reached Europe. Previously, advanced bone tools have only been associated with modern humans but the following study (Soressi et al. 2013) puts these pieces in proper Neanderthal contexts, concluding that the Neanderthals may have had a civilising influence over Upper Paleolithic modern human populations in Europe where lissoirs were commonly used.
Modern humans replaced Neandertals ∼40,000 y ago. Close to the time of replacement, Neandertals show behaviors similar to those of the modern humans arriving into Europe, including the use of specialized bone tools, body ornaments, and small blades. It is highly debated whether these modern behaviors developed before or as a result of contact with modern humans. Here we report the identification of a type of specialized bone tool, lissoir, previously only associated with modern humans. The microwear preserved on one of these lissoir is consistent with the use of lissoir in modern times to obtain supple, lustrous, and more impermeable hides. These tools are from a Neandertal context proceeding the replacement period and are the oldest specialized bone tools in Europe. As such, they are either a demonstration of independent invention by Neandertals or an indication that modern humans started influencing European Neandertals much earlier than previously believed. Because these finds clearly predate the oldest known age for the use of similar objects in Europe by anatomically modern humans, they could also be evidence for cultural diffusion from Neandertals to modern humans.
Specialized bone technology first appears in Africa (1⇓⇓⇓–5) and is widespread in Europe after the arrival of modern humans with the beginning of the Upper Paleolithic (6⇓–8). Modern humans shaped bone by grinding and polishing to produce standardized or so-called formal tools that were used for specific functions (6, 9). Examples of Neandertal bone tools do exist (9⇓⇓⇓⇓⇓–15); however, most of these were made through percussion to mimic existing stone tools, such as handaxes, scrapers, and denticulates. Standardized bone tools in forms distinct from stone tools and shaped by grinding and polishing occur in the Châtelperronian (16) and Uluzzian (17), but (i) whether Neandertals made these assemblage types is debated and, furthermore, (ii) their late date means that Neandertals could have been influenced by modern humans already in Europe (18, 19). Examples with earlier dates are disputed (20). For example, the site of Saltzgitter-Lebenstedt yielded several mammoth ribs modified by percussion and then shaped by grinding (12).
Fig. 3.Photomicrographs of the Pech I (G8-1417) bone showing details of the polish and striations (A–D). Use-wear traces on the upper side of an experimental bone lissoir used to soften dry hide with a longitudinal motion after 5 min of use (E) and after 10 min of use (F).
Fig. 4. Examples of Upper Paleolithic lissoirs. Distal fragment of a Gravettian lissoir from Abri Pataud (France) (45) (A). Distal fragment of a Proto-Aurignacian lissoir from La Grotte du Renne (France) (42) (B) and of a Magdalenian lissoir from La Grotte de la Vache (France) (24) (C). Almost complete Aurignacian lissoir from Gatzarria (France) (D) and mesial fragment (with typical scars of bending fractures at both ends) of a Aurignacian lissoir from Castanet-Nord (France) (46) (E). An unused modern lissoir (upper end) and plior (bottom end) use by leather craftsmen and made from a cow rib, purchased from the Internet, January 2013 (F). [(A) Collection MNHN, photo by C. Vercoutère; (C) Photo by E. Tartar; (D) Castanet project archives.]
These bone tools are identical in outline, profile, and use-wear to lissoirs (Fig. 4 and SI Appendix, Section S6). Lissoirs are known from the early Upper Paleolithic of western Europe (6), including the Châtelperronian (16, 41), Proto-Aurignacian (42), and Aurignacian (22, 23), but are also found in the late Upper Paleolithic (24) through to historic and modern time periods (Fig. 4E). Lissoirs have a standardized shape and vary in size depending on the species used; they are an effective tool for producing and smoothly shifting pressure over a small area (21). This technique, when applied to animal skins, results in tougher, more impermeable, and lustrous hides (21). No other known artifact in the Middle or Upper Paleolithic toolkit could accomplish this task, meaning that these tools exploit specific properties of bone for shaping and use (21).
king The bones reported here demonstrate that Middle Paleolithic Neandertals were shaping animal ribs to a desired, utilitarian form and, thus, were intentionally producing standardized (or formal) bone tools using techniques specific to working bone. These bones are the earliest evidence of this behavior associated with Neandertals, and they move the debate over whether Neandertals independently invented aspects of modern human culture to before the time of population replacement. In central Europe, artifact assemblages contemporaneous with the Pech I Neandertals but more comparable to assemblages from southwest Asia made by modern humans (19, 43) have such poor bone preservation that neither human fossils nor bone tools are known, and thus their influence on Neandertals cannot be evaluated. Thus, it remains to be determined whether MTA lissoirs are evidence that modern humans influenced Neandertals earlier and longer than previously suggested, whether these lissoirs represent independent invention and convergence, or whether, perhaps this time, Neandertals may have influenced subsequent Upper Paleolithic modern human populations in western Europe where lissoirs are common.