Early Stone Age populations living between 1.8 - 1.2 million years ago engineered their stone tools in complex ways to make optimised cutting tools, according to a new study by University of Kent and UCL.
The research, published in the Journal of Royal Society Interface, shows that Palaeolithic hominins selected different raw materials for different stone tools based on how sharp, durable and efficient those materials were. They made these decisions in conjunction with information about the length of time the tools would be used for and the force with which they could be applied. This reveals previously unseen complexity in the design and production of stone tools during this period.
The research was led by Dr Alastair Key, from Kent's School of Anthropology and Conservation, and is based on evidence from mechanical testing of the raw materials and artefacts found at Olduvai Gorge in Tanzania -- one of the world's most important sites for human origins research.
Dr Key collaborated with Dr Tomos Proffitt, from UCL Institute of Archaeology, and Professor Ignacio de la Torre of the CSIC-Centro de Ciencias Humanas y Sociales in Madrid, for the study.
Their research, which employed experimental methods more commonly used in modern engineering research, shows that hominins preferentially selected quartzite, the sharpest but least durable stone type at Olduvai for flake tools; a technology thought to have been used for expedient, short-lived cutting activities.
Chert, which was identified as being highly durable and nearly as sharp as quartzite, was only available to hominins for a short 200,000 year period. Whenever it was available, chert was favoured for a variety of stone tool types due to its ability to maximise cutting performance over extended tool-use durations. Other stone types, including highly durable lavas, were available at Olduvai, however their use varied according to factors such as how long a tool was intended to be used for, a tools potential to create high cutting forces, and the distance hominins had to travel to raw material sources.
The study reveals a level of complexity and flexibility in stone tool production previously unseen at this time. Earlier research had demonstrated Early Stone Age populations in Kenya to select highly durable stone types for tools, but this is the first time cutting edge sharpness has been able to be considered. By selecting the material best suited to specific functional needs, hominins optimised the performance of their tools and ensured a tools efficiency and 'ease-of-use' was maximised.
Dr Key said: 'Why Olduvai populations preferentially chose one raw material over another has puzzled archaeologists for more than 60 years. This has been made all the more intriguing given that some stone types, including lavas and quartzite, were always available.
'What we've been able to demonstrate is that our ancestors were making quite complex decisions about which raw materials to use, and were doing so in a way that produced tools optimised for specific circumstances. Although we knew that later hominin species, including our own, were capable of such decisions, it's amazing to think that populations 1.8 - 1.2 million years ago were also doing so.'
Dr Proffitt added: 'Early hominins during the Oldowan were probably using stone flakes for a variety of tasks. Mostly for butchering animals whilst scavenging, but also probably for cutting various plants and possibly even shaping wood. A durable cutting edge would have been an important factor when using these tools.
'There are many modern analytical techniques used in material sciences and engineering that can be used to interrogate the archaeological record, and may provide new insights into the mechanical properties of such tools and artefacts. By understanding the way that these tools work and their functional limits it allows archaeologists to build up a greater understanding of the capabilities of our earliest ancestors at the dawn of technology.'
The team now hopes that researchers at other archaeological sites will want to apply similar mechanical tests and techniques to help understand the behaviour of Stone Age populations.
###
'Raw material optimisation and stone tool engineering in the Early Stone Age of Olduvai Gorge (Tanzania)' has been published in the Journal of the Royal Society Interface.
For further information and interview or image requests contact the Press Office at the University of Kent.
Tel: 01227 823985
Email: pressoffice@kent.ac.uk
News releases can also be found at http://www.kent.ac.uk/news
University of Kent on Twitter: http://twitter.com/UniKent
Notes to Editors
(1)
Methods
Using controlled mechanical cutting tests, the researchers quantified the force, energy and material displacement required by each stone type when cutting, before using the data to compare edge sharpness and durability. Significant differences were identified, confirming that performance was dependent on raw material choice. They then examined how often each raw material was used to produce specific stone tool types, and how this varied through time and between different archaeological sites at Olduvai.
(2)
The University of Kent is a leading UK university producing world-class research, rated internationally excellent and leading the way in many fields of study. Our 20,000 students are based at campuses and centres in Canterbury, Medway, Athens, Brussels, Paris, Rome and Tonbridge.
With 97% of our research judged to be of international quality in the most recent Research Assessment Framework (REF2014), our students study with some of the most influential thinkers in the world. Universities UK recently named research from the University as one of the UK's 100 Best Breakthroughs of the last century for its significant impact on people's everyday lives.
We are renowned for our inspirational teaching. Awarded a gold rating, the highest, in the UK Government's Teaching Excellence Framework (TEF), we were presented with the Outstanding Support for Students award at the 2018 Times Higher Education (THE) Awards for the second year running.
Our graduates are equipped for a successful future allowing them to compete effectively in the global job market. More than 95% of graduates find a job or study opportunity within six months.
Known as the 'UK's European university', our international outlook is a major focus and we believe in our students developing a global perspective. Many of our courses provide opportunities to study or work abroad; we have partnerships with more than 400 universities worldwide and are the only UK university to have postgraduate centres in Athens, Brussels, Paris and Rome.
The University is a truly international community with over 40% of our academics coming from outside the UK and our students representing over 150 nationalities.
We are a major economic force in south east England, supporting innovation and enterprise. We are worth £0.9 billion to the economy of the south east and support more than 9,400 jobs in the region.
In March 2018, the Government and Health Education England (HEE) announced that the joint bid by the University of Kent and Canterbury Christ Church University for funded places to establish a medical school has been successful. The first intake of undergraduates to the Kent and Medway Medical School will be in September 2020.
We are proud to be part of Canterbury, Medway and the county of Kent and, through collaboration with partners, work to ensure our global ambitions have a positive impact on the region's academic, cultural, social and economic landscape.
About UCL - London's Global University
UCL is a diverse community with the freedom to challenge and think differently.
Our community of more than 41,500 students from 150 countries and over 12,500 staff pursues academic excellence, breaks boundaries and makes a positive impact on real world problems.
We are consistently ranked among the top 10 universities in the world and are one of only a handful of institutions rated as having the strongest academic reputation and the broadest research impact.
We have a progressive and integrated approach to our teaching and research - championing innovation, creativity and cross-disciplinary working. We teach our students how to think, not what to think, and see them as partners, collaborators and contributors.
For almost 200 years, we are proud to have opened higher education to students from a wide range of backgrounds and to change the way we create and share knowledge.
We were the first in England to welcome women to university education and that courageous attitude and disruptive spirit is still alive today. We are UCL.
http://www.ucl.ac.uk| Follow @uclnews on Twitter | Watch our YouTube channel | Listen to UCL podcasts on SoundCloud | Find out what's on at UCL Minds | #MadeAtUCL
Journal
Journal of The Royal Society Interface