Understanding a threshold in Human evolution at 450-350 ka through the roots of Neanderthal behavior. – NEANDROOTS

A large database was created to revise all the occupations of the period, covering more than 40 sites, mainly in Western Europe.

The aim was to use a common methodology to characterise innovations, by revising collections, filling gaps in chronological and environmental data and developing methodological approaches to identify possible regional strategies and models for the spread of innovations.

The climatic reconstruction used pollens analyses and analyses of ice cores to describe in details the climatic data. New dating in geochronology were applied on sites in order to precise the age of key-sites.

And, among other things, to test the impact of climate change on human adaptation using the iLOVECLIM climate model and eco-cultural niche modelling (ECNModelling). Finally, the aim was to understand the emergence of Neanderthals at a behavioural level to help understand their disappearance after several thousand years of existence and the resilience of human groups in the face of climate change.

Results show that, in a climate that rapidly became temperate, human groups develop new strategies that spread afterwards. The extension or retraction of suitable zones for human occupations does not seem to have had any impact on modes of subsistence and technology. Human groups were distinguished more by regional traditions that emerged independently and found their originality in the geographical and geological context.

1) Building a database on behaviour in its geographical and environmental context, with more than 42 sites added to detailed studies of a few key-sites. A bone industry has been identified in Italy.

Detailed technological analyses were applied on some selected key-sites to illustrate the MIS 11 strategies.

2) Compiling chronological and environmental data.

Dating by ERS-U-Th and Ar/Ar has been applied on key-sites. New data from ice cores (global biospheric productivity, δ18Oatm measurements), tuff records and MIS 12/11 and MIS 11c pollen data contribute to a better understanding of the climatic conditions.

3. Identification of regional identities and innovations using cladistics, applied on the whole database in order to identify the location and diffusion of innovations over Western Europe. Regional specificities were observed and possible single location for some key-innovations.

4. Testing the mechanisms of internal dynamics and the role of demography and the specific impact of European climate and vegetation on human behaviour, by ECo-Niche Modelling and climate and vegetation simulations generated by the iLOVECLIM and CARAIB models.

Most of the initial objectives were achieved, despite the health situation, which meant that some fieldwork had to be delayed. As a result, some results, such as those for geochronology, are still pending. However, the team has always maintained a high level of activity, with regular online meetings enabling it to move forward and find alternative solutions if necessary.

The application of cladistics to the lithic series was the first major challenge, requiring months of work to build the database, select the relevant characters, code the files and, above all, interpret the results, which are still being written up. The use of this method is continuing and is currently being developed in an ERC (Lateurope) over an older period and a larger corpus.

The project has also made it possible to meet technical challenges and develop methodological aspects, as in the case of the ECN with its relatively small number of sites and chronological uncertainties. It has enabled different climate models (such as iLOVECLIM) to be put into perspective, enabling comparisons to be made between spatial renderings and habitable zones. The synergy between the team as a whole has made it possible to compare different disciplines and put behavioural and climatic data into perspective. This close interdisciplinarity is being pursued through an ERC (Lateurope).

Most of the initial objectives were achieved.

The application of cladistics to the lithic series was the first major challenge. The use of this method is continuing and is currently being developed in an ERC (Lateurope) over an older period and a larger corpus.

The project has also made it possible to meet technical challenges and develop methodological aspects, as in the case of the ECN with its relatively small number of sites and chronological uncertainties. It has enabled different climate models (such as iLOVECLIM) to be put into perspective, enabling comparisons to be made between spatial renderings and suitable zones. The synergy between the team as a whole has made it possible to compare different disciplines and put behavioural and climatic data into perspective. This close interdisciplinarity is being pursued through an ERC (Lateurope). The final phase of the project, which required data to be accumulated beforehand for the entire duration of the project, is currently being written up, putting the behavioural and climatic data into perspective.

From the hominin evolution perspective, interglacial MIS 11 (including glacial MIS 10 in some places) stands out in Europe. Archaeological remains have highlighted that this period as a threshold. Following MIS 12 glaciation, considered by many as a major climatic driven crisis for Hominins, archaeological records show an increasing number of occupations, evidence of new subsistence behaviours and numerous technical innovations, as well as evidences of an early regionalization of traditions. This threshold time in Western Europe, corresponding to the end of the Lower Paleolithic (and Acheulean) and the beginning of the Middle Paleolithic, is at present under-investigated, in particular as regards why and how innovations appeared and were transmitted among populations. The reasons underlying these changes, pushing back the roots of the Neanderthal world further back, have yet to be identified: (1) Was this behavioral evolution rooted in pre-existing traditions?, (2) Was it due to arrivals of new populations or the onset of Neanderthal from Middle Pleistocene hominids?, (3) Was there a population increase conducive to early regional networks of sites and the diffusion of innovations, or/and (4) Was it due to environmental adaptation to changes in climatic cycles? The last hypothesis is supported by climatic and environmental reconstructions. MIS 12 is a severe glacial period and MIS11 is an exceptionally long interglacial. Such a long-lasting interglacial period after a harsh glacial could have encouraged hominin occupation in Europe. European vegetation is one key, driving biomass availability for large herbivores and affecting the mobility of human groups. As part of this interdisciplinary project, NEANDROOTS proposes: (1) to build a large comprehensive database of existing sites covering the 450 to 350 ka period, (2) to bridge the gap between the chronological framework of the archaeological sites and the environmental data, (3) to develop methodological approaches to identify regional patterns and diffusion models of innovations, (4) to question the role of population size and structure by modelling, and (5) to test the impact of climate evolution on hominin adaptation by iLOVECLIM model and ECN modelling. This innovative contribution to Human Evolution for the period after the MIS 12 aims to contribute to: (1) Building models of hominid responses to various (and new) environments based on the disappearance and acquisition of tools and the expertise retained for successful adaptation, (2) Understanding the mechanisms of cultural transmission over time and the processes by which innovations or inventions spread, and are maintained.
We aim to contribute to understanding the earliest cyclic process of regionalization during prehistoric times, well before those of late Neanderthals (MIS 4-3). This approach has never been undertaken for the beginning of the Neanderthal world. The creation of a homogenous, unified chronostratigraphy will enable us to place new behaviours, technological advances and morphological modifications of hominins in a single climatic and environmental framework. Synoptic maps will encompass climate, vegetation and comprehensive archaeological data with a high resolution. A detailed analysis of interactions between Humans and Environments could become a model for understanding past and current analogous evolutions. Ultimately, we question the resilience of societies to climate change. The close association between physical mechanisms, climate proxy data and archaeological evidence will improve our capacity for trans-disciplinary work and set new boundaries for the method. Our interdisciplinary project involves seven French teams, with complementary specialties: MNHN, LSCE, EPOC/PACEA/University of Bordeaux, IGE, LMD, LGP and University of Lille. An extensive European network will contribute to the project, comprising prehistorians, anthropologist, specialist of micro-wear and of modelling of demography.