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Past dietary reconstructions are based on a number of approaches that involve


assessment of paleo-environments, analyses of macro- and microplant remains (e.g.,


seeds, pits, pollens, phytoliths, residues from cooking vessels) and animal remains


(e.g., bones, teeth, feathers, coprolites) as well as microbial and stable isotope analyses


of food plants, animals, and hominin remains (Pearsall 2000 ; Reitz and Wing 2008 ).


Stable isotopes of carbon, nitrogen, and strontium found in bone collagen, apatite, and


dental enamel are biomarkers of dietary intake that are widely used in materials found


in archaeological contexts (Tykot 2004 ). Isotopic ratios can provide information on the


types of plants consumed, relative amounts of protein and sources such as marine


versus terrestrial animals. Isotopic biomarkers in teeth provide information on


migration patterns and diet during development (Tykot 2004 ). Recent analyses of fecal


biomarkers indicate that Neandertals from Spain (ca. 50,000 years B.P.) had a diverse


diet with high intakes of meat (high coprostanol proportions) but also significant plant


intake (presence of 5β-stigmastan) (Sistiaga et al. 2014 ). The relative importance of


meat versus plant foods in paleo-diets has not been resolved (Armelogos 2010 ;Milton


2003 ; Ungar 2007 ; Ungar and Sponheimer 2011 ; Ungar and Teaford 2002 )but


contemporary paleo-diet enthusiasts favor diets incorporating substantial amounts of


animal protein (Konner and Eaton 2010 ).


Complex polygenic/environmental interactions were involved in four anatomical


evolutionary trends that have a bearing on contemporary food-related behaviors and
fat storage efficiency. The earliest trend was for increasing body size from the 4


million-year-old australopithecine/paranthropine roots to modern Homo sapiens


(Foley 2011 ; McHenry and Coffing 2000 )(Table10.1). Larger body size requires


more calories and macro- and micronutrients for basal metabolic maintenance, growth,


and repair of tissues, physical activities, and for reproduction in females (Leonard and


Robertson 1992 ; Power and Schulkin 2009 ). Larger size has advantages because


resting energy efficiency increases per unit body size. This relationship is represented


by Kleiber’s law that holds for animals of all sizes: basal metabolic rate (R)is


proportional to the¾power of an animal’smass(M)(PowerandSchulkin 2009 ). The


implications are twofold: (1) larger animals overall need more energy but can utilize


lower energy-dense foods than smaller animals; and (2) larger animals are more


flexible regardingfluctuations in the food supply and energy intake because they can


draw upon larger energy reserves (Power and Schulkin 2009 ). These evolutionary


adaptations in modern food environments of stable, abundant, energy-dense foods


facilitate the accumulation of adipose tissue especially when there are low demands on


adipose energy reserves (Lieberman 2006 ). Table10.1summarizes these hominin


evolutionary trends in body and brain size.


Second, in the Late Pleistocene the movement of hominin populations from the


warm/hot climates of Africa to the colder/temperate climates of Eurasia increased


caloric needs to maintain body temperature and favored stocky torsos (Bergmann’s


rule), shorter limbs (Allen’s rle), and a remodeling of the face (e.g., enlarged


sinuses) and increase in cranial capacity facilitating thermoregulation (Ash and


Gallup 2007 ; Leonard and Katzmarzyk 2010 ; Snodgrass et al. 2009 ). One result


was an increase in the encephalization quotient (EQ) that expresses brain size
relative to body mass (Aiello and Wheeler 1995 ; Armelogos 2010 ).


10 Objective and Subjective Aspects of the Drive to Eat in... 197

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