Good evening class. Today's topic is my research. I will try to keep this relatively short and straightforward but please do not hesitate to interrupt should you have a question. Let's begin.
I study the raw materials used to make stone tools. Specifically I am interested in the characterization (description) and sourcing of these lithic raw materials in order to infer mobility patterns, trade and exchange, and resource exploitation. Basically, I look at and describe the different types of raw materials (including, but not limited to, chert) found in stone artifact assemblages and try to determine how they were being used and where they come from.The goal of this is to go from looking at stone artifacts to actually saying something about the behaviour, culture, and worldview of the people who made them.
In particular I am intrigued by the use of chert. Chert is, well, awesome. In the real world, it is just a type of sedimentary rock and, in honour of my pledge to keep this simple, a "variant" of chert - jasper - is often considered semi-precious and is used in jewelry. In my world, chert is a highly variable, high quality raw material for making tools. Different outcrops (sources) of chert can vary significantly from other sources in the same region. This means, in theory, that I can look at the different types of chert recovered in an assemblage at a single site, and between sites, to answer a number of questions relating to technology. To get a bit more science-y, chert is fascinating because geologists still cannot quite agree over how it forms. Generally it is agreed that there is some sort of precipitation and lithification process that involves siliceous microorganisms. Often we can find microfossils which are incorporated into the chert during formation. These microfossils can be specific to particular formations which can assist in determine what source a chert is coming from. Neat huh!?
Back to my current research...I am looking at the raw materials from two stone age sites in Tanzania. I am conducting work on sites there as Tanzania is important in terms of human evolution. Both genetic and fossil evidence place the origin of our species, Homo sapiens sapiens (anatomically modern humans), to East Africa. Now there is a whole bunch of discussion in the Africanist world about the relationship between anatomical modernity and behavioural modernity. As we know when we became anatomically modern (around 300,000 years ago give or take a couple thousand years) the question is when did we start behaving like modern humans. Now there is a whole grocery list of features that are argued make up behavioural modernity (i.e. art, personal adornment, etc.). Most of these indicators were derived from European Upper Palaeolithic assemblages - sites dating to after the expansion of modern humans into Eurasia from Africa (note: there is a counter argument to the idea that modern humans evolved in Africa but it is currently not the dominant paradigm. I will have to leave that debate to another post). What this suggests is that behavioural modernity developed after anatomical modernity. For those of us working in East Africa one of the things we are trying to do is identify these indicators or traits in our assemblages and see if we can pin down when the transition to modernity occurs. Luckily our research area Iringa (see earlier post) has sites that date to the period when we see the rise of anatomical modernity, and, hopefully, also contain the period of transition to behavioural modernity.
If you are following me so far you are probably wondering how this directly relates to what I do (i.e. all the stuff with the rocks and chert). Well, it is argued that a key modern behaviour is the establishment and maintenance of long distance trade and exchange networks. By looking at where and how stone raw materials were acquired and used, it may be possible for me to infer if there were long distance trade/exchange networks. My analyses demonstrate the presence of a number of the behaviours attributed to modern humans.
Obviously my research is just one small part of the larger research project headed by my PhD supervisor, and there are other archaeologists and palaeoanthropologists from around the world who are also working on this time period and these questions. In general, those of us looking at these questions have found that in fact behavioural modernity did develop before our anatomically modern ancestors left Africa to populate the rest of the world.