A brief review of the archaeological evidence for Palaeolithic and Neolithic subsistence

Knowledge of our ancestor's diets is becoming increasingly important in evolutionary medicine, as researchers have argued that we have evolved to specific type of 'Palaeolithic' diet, and many modern nutritional disorders relate to the mismatch between the diet to which we have evolved, and the relatively newer agricultural-based 'Neolithic' diets. However, what is the archaeological evidence for pre-agricultural diets and how have they changed over the four million years of hominid evolution? This paper briefly introduces the three lines of evidence we have for Palaeolithic and Neolithic diets; morphological changes, archaeological material evidence, and direct measurement of diet from bone chemistry. The morphological changes, increasing gracilization of the mandible and increasing brain size have been interpreted (based on analogies with living primates) as the move from plants to higher-quality, more digestible, animal meat, although this is debated. The archaeological evidence is especially weak, as many organic materials, especially plants, do not survive well, and are therefore invisible in the archaeological record. Artefacts, such as stone tools which are likely to be used for hunting and animal bones with evidence of human processing and butchering do indicate that hunting did occur at many times in the past, but it is impossible to judge the frequency. Direct evidence from bone chemistry, such as the measurement of the stable isotopes of carbon and nitrogen, do provide direct evidence of past diet, and limited studies on five Neanderthals from three sites, as well as a number of modern Palaeolithic and Mesolithic humans indicates the importance of animal protein in diets. There is a significant change in the archaeological record associated with the introduction of agriculture worldwide, and an associated general decline in health in some areas. However, there is an rapid increase in population associated with domestication of plants, so although in some regions individual health suffers after the Neolithic revolution, as a species humans have greatly expanded their population worldwide.