Final Report Summary - HUMANARIDADAPT (HUMAN ADAPTATIONAL PATTERNS TO ARID ENVIRONMENTS IN NORTH AFRICA)
The project investigated the relationship between human behaviour, environmental conditions and the subsistence system practised by hunter-gatherers groups in North Africa in the period between about 40,000 years ago and the end of the Pleistocene (the ‘Ice Ages’) and the beginning of the modern climatic era (the Holocene) around 11,500 years ago. The main research questions addressed in the project were: (1) What activities were practised by Late Pleistocene hunter-gatherers at particular sites? (2) Why did they develop microlithic technologies? (3) What did they use their lithic artefacts for? (4) How did they acquire the raw materials they needed? (5) How did hunting-gathering strategies adapt to climatic change? The study involved the analysis by Dr Mutri of the visual characteristics of a large collection of stone tools collected in recent and ongoing excavations in the Haua Fteah cave in Cyrenaica (northeast Libya), combined with microscopic analysis of traces of wear damage and organic residues attached to the surfaces of a selected sample of tools. The analysis was informed by experimental work on a sample of replica artefacts. Her systematic statistical analysis of the Haua Fteah lithics indicates that the intensity of occupation in the cave increased dramatically with the Oranian phase from around 17,000 years ago, that is, following the peak of arid climatic conditions (the Last Glacial Maximum, globally dated to around 20,000 years ago). The main technological difference between the Dabban (c.42,000-17,000 years ago) and Oranian (c.17,000-11,500 years ago) lithic technologies was a decrease in the size of tools, or ‘microlithicisation’, a process that appears to have started rather abruptly. Using microscopic trace wear and residue analysis of the archaeological artefacts, with interpretation being informed by the experimental firing study, the research investigated whether this development represented a new specialist hunting technology based on composite projectiles, as frequently assumed, or a highly versatile and multi-purpose technology, as some recent studies elsewhere imply. Her results show that both hypotheses can be supported: organic hafting residues on some tools and associated usewear such as impact damage show that specialist composite spears were developed after the Last Glacial Maximum but that these tools were just one part of a versatile multi-purpose toolkit.
In terms of the project objectives, the principal findings are:
(1) The multi-purpose Oranian toolkit indicates a significant expansion in the range of subsistence activities after the LGM;
(2) The development of this toolkit was a critical response to climatic instability;
(3) The population of the Gebel Akhdar developed specialist hunting tools to aid in the hunting of both medium-sized animals like Ammotragus lervia (Barbary sheep, the principal hunted animal in earlier periods) and smaller game, and multi-purpose toolkits to use in hunting, plant gathering, shell processing, wood- and bone-working etc;
(4) The lack of exotic stone suggests that most raw materials used for Oranian toolkits were gathered locally (but this is only a general observation as systematic fieldwork across the Gebel Akhdar became impossible after the 2011 civil unrest), perhaps an indicator of decreased mobility after the LGM;
(5) Dr Mutri’s work on the lithics provides critical support for other studies within the ERC-funded TRANS-NAP project directed by the PI indicating that the principal way that Cyrenaican people adapted to climatic instability during and after the LGM was to develop broad-spectrum subsistence activities including hunting a wider range of animals, collecting and storing seeds and nuts, and collecting landsnails and shellfish, probably in smaller-scale systems of movement than were practised by Dabban hunters.