Natural Science Forum / Biology / Paleontology / October 2006

On the Last Neanderthals

The following points are made by E. Delson and K. Harvati (Nature 2006 443:762):

1) The last Neanderthals were participants in one of the most dramatic events in the story of human evolution. At a time of increasing climatic instability and environmental deterioration, they would have had to have survived in ever-smaller groups, confined to less environmentally hostile refugia on the coast of the Mediterranean, and competing for access to resources with modern humans pressing on their territory. These conditions are widely thought to have led to the Neanderthals' extinction within a relatively short time after the colonization of Europe by modern humans (1). But new work (2) revises that model considerably. The new work produces dating results from Gorham's Cave, Gibraltar, that might indicate that a group of Neanderthals survived extinction in this part of southern Iberia until at least 28,000 years ago -- thousands of years after anatomically modern humans had firmly established themselves as the inheritors of the European continent.

2) Neanderthals inhabited western Eurasia from a time in the Middle Pleistocene between 500,000 and 160,000 years ago [depending on the definition of the earliest members of the Neanderthal group (3,4)] until approximately 30,000 years ago. They were characterized by a suite of specialized morphological features, many of them unique to the group, that together make them highly distinct from modern humans. Their skeletal remains are often found associated with "Mousterian" stone tools, named after the Le Moustier site in France. In Europe -- but not in northwest Africa or southwest Asia -- such tools are exclusively found with Neanderthals, and are presumed to have been made by them.

3) The find of Finlayson et al (2) of Mousterian tools in Gorham's Cave, Gibraltar, might be the most recent indication of Neanderthal settlement yet. Zafarraya (Spain) and Figueira Brava (Portugal) have yielded southern Iberian putative late Neanderthal fossils, whereas St. Césaire and Arcy-sur-Cure (both France) are slightly older (between 35,000 and 30,000 years old). Also indicated are Le Moustier, the eponymous site for the Mousterian tool industry, and Feldhofer, the site of the initial Neander Valley find of 1856. Vindija (Croatia) and Mezmaiskaya (Russia) are noted by Finlayson et al (2) as having recently been redated to older than 30,000 years ago. Subalyuk (Hungary), Guattari (Italy), Amud (Israel) and Shanidar (Iraq), as well as Feldhofer and Le Moustier, are older than 35,000 years, but they give an indication of the geographical range of the last glacial Neanderthal finds; sites farther east, such as Teshik-Tash, have recently been the subject of questions as to the identity of the fossils recovered.

4) Neanderthal remains discovered from times near the end of their existence are sometimes found with tool assemblages resembling those produced by early modern humans. This is possibly a result of acculturation or imitation of modern human technology (5). Although there is still some discussion over the Neanderthals' taxonomic status and their relationship to modern humans, it is now widely recognized that they represent a distinct, Eurasian evolutionary lineage. They shared a common ancestor with modern humans in the early Middle Pleistocene or before (3), but became isolated thereafter from the rest of the Old World. Glacial climatic conditions are considered at least in part responsible for this isolation and for the evolution of some distinctive features of Neanderthal morphology, especially their short limbs and heavy trunks. These are similar to, but more extreme than, features of cold-adapted modern populations such as the Inuit.

References (abridged):

1. Mellars, P. Nature 439, 931-935 (2006).

2. Finlayson, C. et al. Nature 443, 850-853 (2006).

3. Delson, E. & Baab, K. in McGraw-Hill Encyclopedia of Science and Technology Vol. 7, 464-478 (in the press).

4. Harvati, K. & Harrison, T. (eds) Neanderthals Revisited: New Approaches and Perspectives (Springer, Dordrecht, in the press).

5. Harrold, F. B. in The Human Revolution: Behavioural and Biological Perspectives on the Origins of Modern Humans (eds Mellars, P. & Stringer, C.) 677-713 (Princeton Univ. Press, 1989).

Source: ScienceWeek
http://scienceweek.com/2006/sw061027.htm

Posted by
Robert Karl Stonjek