Apartheid of Iberian Neandertals & modern humans

The Middle-to-Upper Palaeolithic transition in Cova Gran (Catalunya, Spain) and the extinction of Neanderthals in the Iberian Peninsula:

The excavations carried out in Cova Gran de Santa Linya (Southeastern PrePyrenees, Catalunya, Spain) have unearthed a new archaeological sequence attributable to the Middle Palaeoloithic/Upper Palaeolithic (MP/UP) transition. This article presents data on the stratigraphy, archaeology, and 14C AMS dates of three Early Upper Palaeolithic and four Late Middle Palaeolithic levels excavated in Cova Gran. All these archaeological levels fall within the 34-32 ka time span, the temporal frame in which major events of Neanderthal extinction took place. The earliest Early Upper Palaeolithic (497D) and the latest Middle Palaeolithic (S1B) levels in Cova Gran are separated by a sterile gap and permit pinpointing the time period in which the Mousterian disappeared from Northeastern Spain. Technological differences between the Early Upper Palaeolithic and Late Middle Palaeolithic industries in Cova Gran support a cultural rupture between the two periods. A series of 12 14C AMS dates prompts reflections on the validity of reconstructions based on radiocarbon data. Thus, results from excavations in Cova Gran lead us to discuss the scenarios relating the MP/UP transition in the Iberian Peninsula, a region considered a refuge of late Neanderthal populations.

ScienceDaily has a lot more. Here's the important point I think:

The samples obtained at Cova Gran using Carbon 14 dating refer to a period of between 34,000 and 32,000 years in which this biological replacement in the Western Mediterranean can be located in time, although the study regards as relative the use of Carbon 14 for dating materials from the period of transition of the Middle to Upper Palaeolithic period( 40,000 and 30,000).

The results also support the hypothesis that there was neither interaction nor coexistence between the two species.

There's long been a model that modern humans replaced Neandertals without coming into direct conflict with them. The model would be that modern humans simply disrupted the ecology which the Neandertals depended upon. It seems a bit too pat for me, but considering the very low population densities of hunter-gatherers, and in particular Neandertals, perhaps it is possible.

Citation: The Middle-to-Upper Palaeolithic transition in Cova Gran (Catalunya, Spain) and the extinction of Neanderthals in the Iberian Peninsula, doi:10.1016/j.jhevol.2009.09.002