Dental calculus indicates widespread plant use within the stable Neanderthal dietary niche

Abstract

The ecology of Neanderthals is a pressing question in the study of hominin evolution. Diet appears to have played a prominent role in their adaptation to Eurasia. Based on isotope and zooarchaeological studies, Neanderthal diet has been reconstructed as heavily meat-based and generally similar across different environments. This image persists, despite recent studies suggesting more plant use and more variation. However, we have only a fragmentary picture of their dietary ecology, and how it may have varied among habitats, because we lack broad and environmentally representative information about their use of plants and other foods. To address the problem, we examined the plant microremains in Neanderthal dental calculus from five archaeological sites representing a variety of environments from the northern Balkans, and the western, central and eastern Mediterranean. The recovered microremains revealed the consumption of a variety of non-animal foods, including starchy plants. Using a modeling approach, we explored the relationships among microremains and environment, while controlling for chronology. In the process, we compared the effectiveness of various diversity metrics and their shortcomings for studying microbotanical remains, which are often morphologically redundant for identification. We developed Minimum Botanical Units as a new way of estimating how many plant types or parts are present in a microbotanical sample. In contrast to some previous work, we found no evidence that plant use is confined to the southern-most areas of Neanderthal distribution. Although interpreting the ecogeographic variation is limited by the incomplete preservation of dietary microremains, it is clear that plant exploitation was a widespread and deeply rooted Neanderthal subsistence strategy, even if they were predominately game hunters. Given the limited dietary variation across Neanderthal range in time and space in both plant and animal food exploitation, we argue that vegetal consumption was a feature of a generally static dietary niche.

Aspects of human physical and behavioural evolution during the last 1 million years

“…This complements the theory discussed earlier that Neanderthal morphologies were adapted to encourage heat production, as studies have indicated that a high protein diet considerably increases heat production from metabolism (Snodgrass and Leonard, 2009). However, in spite of Neanderthals' frequent reconstruction as almost exclusively reliant on meat as a primary food source, recent studies using the analysis of dental calculus have found that Neanderthals also consistently incorporated plants into their diet and this may have been an integral part of a species-wide niche (Power et al, 2018).…”

Pleistocene dental calculus: Recovering information on Paleolithic food items, medicines, paleoenvironment and microbes

“…The starch granules and phytoliths were placed into morphological types, which were correlated with modern plant samples and published reference material to identify plant origin of the microremains. Further analyses of Neanderthal and Upper Paleolithic individuals recovered principally starch granules and phytoliths (Table ).…”

“…Based upon the morphological analyses of recovered starch granules and phytoliths, Henry et al Salazar Garcia et al, and Power et al, (Table ) have developed dietary and behavioral models. Henry et al proposed a broad behavioral model using the data from dental calculus samples (Table ) together with an additional 360 starch granules recovered from stone tools from six sites.…”

“…Power et al suggest that the broad range of microfossils recovered indicates that starchy food was not a primary feature of the diet at El Mirón; they suggest agaric and bolete mushrooms may have been a feature of the diet. Power et al used statistical modeling of their starch granule and phytolith finds (approximately 305 starch granules and 162 phytoliths from 13 sites) to propose a broad model correlating plant consumption with regional paleoenvironments. However, of the 13 sites analyzed, seven had less than 10 remains and in one case (La Chapelle aux Saints) no recovered items at all …”

“…Based upon the morphological analyses of recovered starch granules and phytoliths, Henry et al 8,15,17 Salazar Garcia et al, 9 and Power et al, 18,21 (Table 1) have developed dietary and behavioral models.…”