Neanderthal palaeodiet was dependant on habitat
The choice of diet for Homo neanderthalensis was dependant on geographical location is the conclusion of Dr. Luca Fiorenza, lead author of the recently published article in PLoS ONE. Whereas previous studies assume specific dietary specializations, the team suggest that the diet of both Neanderthals and early Homo sapiens is determined by ecological conditions.
Neanderthal diets are reported to be based mainly on the consumption of large and medium sized herbivores, while the exploitation of other food types including plants has also been demonstrated in previous studies. Though some studies conclude that early Homo sapiens were active hunters, the analyses of faunal assemblages, stone tool technologies and stable isotopic studies indicate that they exploited broader dietary resources than Neanderthals.
Analysis of molar wear patterns using occlusal fingerprint analysis derived from optical 3D topometry. Molar macrowear accumulates during the lifespan of an individual and thus reflects diet over long periods. Neanderthal and early Homo sapiens maxillary molar macrowear indicates strong eco-geographic dietary variation independent of taxonomic affinities. Based on comparisons with modern hunter-gatherer populations with known diets, Neanderthals as well as early Homo sapiens show high dietary variability in the Mediterranean evergreen habitats while a more restricted diet in upper latitude steppe/coniferous forest environments, suggests a significant consumption of high protein meat resources.
Stone Age diet debate
It has long been assumed that the Neanderthals had a specific, exclusive and specialised diet. Early Homo sapiens however, as well as hunting, took advantage of additional resources and were more flexible in the choice of food than Neanderthals. Neanderthals had previously been presented as having a high proportion of meat in their diet.
In the deposits of Amud and Kebara caves in Israel, remnants of pistachios, acorns, and even root vegetables have been uncovered. The processing of herbs also shows from microwear analysis of the stone tools from La Quina in France. The newly discovered microfossils of plant residues found in the calculus of “Shanidar 3″ from northern Iraq and a wide variation in the micro-wear traces on the tooth enamel means the limited interpretation of a simple and singular diet of meat is no longer plausible.
Dr. Ottmar Kullmer at Senckenberg Research Institute developed “Occlusal Fingerprint Analysis Method” (OFA) to examine the considerable variability in the wear patterns of the tooth surfaces. It was found that tooth samples from individuals of identical eco-geographical regions show similar food-related wear on the chewing surfaces.
Was this not obvious?
In a way it is fairly obvious that prehistoric humans would utilise all the edible material which would be found in an area. However, there had been a general long standing overestimation of the meat content in the Neanderthal diet. One reason was, according to Fiorenza, that as bones are more likely to appear in the archaeological assemblage rather than plants, they are more likely to provide evidence of a meat rich rather than vegetable diet and the evidence for other material was not being actively investigated. In addition, previous studies on Neanderthal diet frequently included samples from the periods during a cooler climate meaning the variability in the diet would have been restricted due to climatic conditions.
Show me your teeth and I can tell you what you eat
Because different food stuffs changes the dental relief of a tooth the resulting tracks are compiled during the individuals lifetime into a characteristic pattern on the tooth surfaces. Ottmar Kullmer explains: “With both fossil and existing species, we can analyse teeth using the new OFA method, at which point we can interpret the chewing pattern and diet very closely.” The scientists create a model which contain a wealth of information – scanned copies are in high-resolution three-dimensional views allowing all facets to be precisely measured.
What emerges in super-macro imagery, is similar to a topographic map: In addition to ridges and grooves on the landscape of the occlusal surface are heavily eroded areas with significant wear marks. “These are facets that have formed in contact with the opposing tooth in the lower jaw,” said Ottmar explains. The scientists explained that the facets are dependant on the nature of the food and are also formed in different areas of the tooth. “The mastication adapts to the food type an individual inserts between the teeth.”
Kullmer adds, “The chewing can be divided into two phases. First, the food is crushed and secondary grinding takes place”. Depending on the material which is chewed, such as harder roots and stems, softer plant parts such as fruits and seeds or fibrous meat, the contact between the teeth is different and measurable. In addition to this the relationship between food, food source and eco-geographical differences determine the habitat, that is being occupied” Ottmar explains.
Corrected image of the Neanderthal
“Our analysis now clearly shows that the diet of both species of the genus Homo was generally varied and was determined primarily by the eco-geographical conditions,” says Luca Fiorenza, adding: “This contradicts the view of a Neanderthal-specific specialized food strategy and corrects the picture of the Neanderthal only consuming meat. “
The scientists have examined and compared the chewing surfaces of 73 maxillary molars. In addition to analysis of Neanderthals and early Homo sapiens from different regions they also examined the back teeth of present day people who eat mainly meat or have a mixed diet. These include Inuit, residents of Vancouver Island, Tierra del Fuego, Aborigines and the Khoisan from southern Africa.
Included with present day habitat data on wildlife, vegetation and soils the data provides a fingerprint of three eco-geographical regions (deciduous forest, a Mediterranean evergreen, steppe / coniferous forest) that can be associated with the results of the OFA correlation method.
- Full article from PLoS ONE http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0014769 including references to prior studies.
- Tertiary Mammals Section – Senckenberg Research Institute and Natural History Museum