doi:10.1016/j.jas.2009.06.003 Journal of Archaeological Science
Energy use by Eem Neanderthals
Bent Sørensena, Department of Environmental, Social and Spatial Change, Roskilde University, DK 4000 Roskilde, Denmark.
An analysis of energy use by Neanderthals in Northern Europe during the mild Eem interglacial period is carried out with consideration of the metabolic energy production required for compensating energy losses during sleep, at daily settlement activities and during hunting expeditions, including transport of food from slain animals back to the settlement. Additional energy sources for heat, security and cooking are derived from fireplaces in the open or within shelters such as caves or huts. The analysis leads to insights not available from archaeological findings that are mostly limited to durable items such as those made of stone: Even during the benign Eem period, Neanderthals faced a considerable heat loss problem. Wearing tailored clothes or some similar measure was necessary for survival. An animal skin across the shoulder would not have sufficed to survive even average cold winter temperatures and body cooling by convection caused by wind. Clothes and particularly footwear had to be sewn together tightly in order to prevent intrusion of water or snow. The analysis of hunting activity evolvement in real time further shows that during summer warmth, transport of meat back to the base settlement would not be possible without some technique to avoid that the meat rots. The only likely technique is meat drying at the killing site, which indicates further skills in Neanderthal societies that have not been identified by other routes of investigation.
1. Introduction and background
The Neanderthals had an average body mass above that of modern humans, a more sturdy bone structure and a lower height. Food was primarily obtained by hunting big game. The aim of the present paper is to explore the energy requirements of Neanderthals during the warm interglacial Eem period (around 125 ky BP), and based on such analysis to discuss the need for clothes and footwear, as well as methods for food conservation and preparation. The climatic environment is taken as that of Northern Europe, using Eem temperature data from Bispingen close to the Neanderthal site Lehringen near Hamburg (Kühl and Litt, 2007). The climatic conditions would be similar in most of Northern Germany, Belgium and Denmark, while Eastern Europe would have slightly colder winters, as would Finland. Some 30 European Neanderthal sites dating from the Eem, with roughly equal shares in Southern, Middle and Northern Europe, are listed by Wenzel (2007). Traces of seasonal presence have been found at Hollerup, Denmark (Møhl-Hansen, 1954) and at Susiluola Cave, Finland (Schulz, 2001, 2006), indicating that Neanderthals had a high mobility. Assuming a group * Correspondence: email@example.com (Bent Sørensen)
size of 25 (Hassan, 1981), the total European Neanderthal population at any given time within the Eem period could have been around 1000, depending on how many sites were simultaneously populated and which fraction the sites surviving and found are of the true settlement count. Patou-Mathis (2000) lists 73 Eem settlement levels in Middle and Northern Europe, indicating that some sites were re-occupied at different times within the Eem period. Throughout their presence in Europe, the diet of Neanderthals consisted mainly of meat. Large herbivores seem to have been actively hunted rather than scavenged (Bocherens et al., 2005). The Neanderthal hunting strategy was to specialise and concentrate on a few large herbivore mammal species, among which horse (equus sp.) red deer (cervus elaphus), woolly rhinocerous (coelodonta antiquitatis), woolly mammoth (mammuthus prinigenius) and bison (bison priscus) were present both during the Eem interglacial and the adjacent colder periods. During the Eem, additional forestbased species appeared, and the volume of species preferring open space, such as mammoth, was lower than in adjacent periods: mammoth is found in 22.5% of the Eem-occupied site levels considered by Patou-Mathis (2000), but in 50-60% of the levels belonging to adjacent time periods. Mammoth is in this study selected as an example for investigating the energy use involved in Neanderthal hunting, slaying and readying meat for eating, because of its size that demands a maximum of logistic skills by the hunters. However, proof of mammoth presence in North-Western Europe during the Eem period is nearly absent. Mammoth remains have been found in Grotte Scladina, Belgium (in level 4, dated by thermo-luminescence to between 106 and 133 ky BP, and in level 5, dated to 110-150 ky BP), but according to magnetic susceptibility relative dating in the lowest part of the uncertainty intervals and thus possibly younger than the marine isotope stage 5e usually associated with the Eem period (Döppes et al. 2008; Ellwood et al., 2004). The scarcity of mammoth finds at the settlement sites may be explained by only meat, not bones, being carried back to camp after a kill (Patou-Mathis, 2000; Balter and Simon, 2006). A straight-tusked elephant, a species preferring the warmer Eem environment, has been found at Lehringen with a Neanderthal spear through its rib, so it could also have been used as an example of extreme-weight prey. In the assessment made in the present study, the species exemplified is represented by its meat-mass alone, and results (such as energy-use by carrying) scale directly with the mass of the parts transported back to the group. Large herbivores were hunted and killed by sinking spears into their body by a party of several Neanderthals (Wenzel, 2007). Spears were rarely thrown, as deduced from the absence of shoulder and upper arm bone asymmetries characteristic of more recent hunters using spear-throwing techniques (Rhodes and Churchill, 2009). The Neanderthal population density was low enough to make big-game hunting sustainable, and famines due to insufficient food would not normally occur (Harpending, 1998). One similar analysis of needs for clothes and footwear has been made for the marine isotope stage 3 around 40 ky BP (Aiello and Wheeler, 2004), however with some unrealistic features: It uses subjective wind-chill temperatures (Lee, 2001) in the heat-loss expression valid for real temperatures (to which heat loss by the action of wind could have been added in the way it is done below), and it uses an arbitrary increase of the average metabolic rate to three times the basic one. This is suggesting an ability of the Neanderthal body to regulate its metabolism according to ambient temperature (Steegmann et al., 2002), in contrast to the body of modern humans, where this can be done only in a very minor way in infants, through adrenaline stimulation of a special fat deposit in brown adipose tissues (BAT) near the shoulder (Farmer, 2009). Steegmann et al. (2002) suggest that recent Tierra del Fuego Ona (Selk’nam) aborigines had a particular cold adaptation and that the Neanderthals might also have had it. However, no search for BAT in Ona remains has to my knowledge been made, and the photo reproduced in Steegmann et al. (2002) shows people posing for a 1901-picture, dressed in heavy fur and similar hats, but with bare feet or moccasins. To make inferences, one should have time distributions of clothing used and corresponding temperatures, and to
to compare with Neanderthals, the differences between the Ona, deriving their food from the camellike guanaco, from gathering and from fishing, e.g of seal, and the Neanderthal providing food by big-game hunt with walking or running over extended distances and durations should be kept in mind. The Neanderthals would during cold periods be better compared with present or recent Inuit populations, which use several layers of clothing and heavy, furred footwear. Should the Neanderthals really have had a genetic advantage in cold adaptation that modern humans do not have, it becomes more difficult to understand why modern humans and not Neanderthals survived the cooling period up to the last glacial maximum, 40-20 ky BP. Without ad hoc assumptions on the genetic make-up of Neanderthals, one must assume that in order to increase metabolism, muscle work is required, so that a sleeping and freezing Neanderthal person must get up and swing the arms, jump up and down or otherwise perform the muscle work that will bring the level of metabolism up and create the associated heat that can keep the body warm. Generating a total of 300 W of heat (including the basic metabolic heat production during sleep of 80-90 W) requires about 100 W of muscle work (Sørensen, 2004, p. 17). The analysis of energy production and use presented below is divided into two parts: first the energy balance is evaluated during sleep, and then the various components of energy production and use during activities taking up the wake time of Eem Neanderthals.
And from genetic studies:
Arctic Inuit, Native American cold adaptations may originate from extinct hominids
December 20, 2016, Molecular Biology and Evolution (Oxford University Press)
- In the Arctic, the Inuits have adapted to severe cold and a predominantly seafood diet. Now, a team of scientists has followed up on the first natural selection study in Inuits to trace back the origins of these adaptations. The results provide convincing evidence that the Inuit variant of the TBX15/WARS2 region first came into modern humans from an archaic hominid population, likely related to the Denisovans.