Authors
  Leonard WR.  Robertson ML.  Snodgrass JJ.  Kuzawa CW.
Title
  Metabolic correlates of hominid brain evolution [Review]
Source
  Comparative Biochemistry & Physiology. Part A, Molecular & Integrative
  Physiology. 136(1):5-15, 2003 Sep.
Abstract
  Large brain sizes in humans have important metabolic consequences as
  humans expend a relatively larger proportion of their resting energy
  budget on brain metabolism than other primates or non-primate mammals. The
  high costs of large human brains are supported, in part, by diets that are
  relatively rich in energy and other nutrients. Among living primates, the
  relative proportion of metabolic energy allocated to the brain is
  positively correlated with dietary quality. Humans fall at the positive
  end of this relationship, having both a very high quality diet and a large
  brain size. Greater encephalization also appears to have consequences for
  aspects of body composition. Comparative primate data indicate that humans
  are 'under-muscled', having relatively lower levels of skeletal muscle
  than other primate species of similar size. Conversely, levels of body
  fatness are relatively high in humans, particularly in infancy. These
  greater levels of body fatness and reduced levels of muscle mass allow
  human infants to accommodate the growth of their large brains in two
  important ways: (1) by having a ready supply of stored energy to 'feed the
  brain', when intake is limited and (2) by reducing the total energy costs
  of the rest of the body. Paleontological evidence indicates that the rapid
  brain evolution observed with the emergence of Homo erectus at
  approximately 1.8 million years ago was likely associated with important
  changes in diet and body composition. (C) 2003 Elsevier Science Inc. All
  rights reserved. [References: 53]
Institution
  Reprint available from:
  Leonard WR
  Northwestern Univ, Dept Anthropol, Lab Human Biol Res
  1810 Hinman Ave
  Evanston, IL 60208
  USA

Authors
  Sponheimer M.  Lee-Thorp JA.
Title
  Differential resource utilization by extant great apes and
  australopithecines: towards solving the C-4 conundrum [Review]
Source
  Comparative Biochemistry & Physiology. Part A, Molecular & Integrative
  Physiology. 136(1):27-34, 2003 Sep.
Abstract
  Morphological and biogeochemical evidence suggest that australopithecines
  had diets markedly different from those of extant great apes. Stable
  carbon isotope analysis, for example, has shown that significant amounts
  of the carbon consumed by australopithecines were derived from C,
  photosynthesis in plants. This means that australopithecines were eating
  large quantities of C-4 plants such as tropical grasses and sedges, or
  were eating animals that were themselves eating C-4 plants. In contrast,
  there is no evidence that modern apes consume appreciable amounts of any
  of these foods, even,in the most and extents of their ranges where these
  foods are most prevalent. Environmental reconstructions of early
  australopithecine environments overlap with modem chimpanzee habitats.
  This, in conjunction with the stable isotope evidence, suggests that
  australopithecines and great apes, even in similar environments, would
  utilize available resources differently. Thus, the desire or capacity to
  use C-4 foods may be a basal character of our lineage. We do not know,
  however, which of the nutritionally disparate C-4 foods were utilized by
  hominids. Here we discuss which C-4 resources were most likely consumed by
  australopithecines, as well as the potential nutritional, physiological,
  and social consequences of eating these foods. (C) 2003 Elsevier Science
  Inc. All rights reserved. [References: 66]
Institution
  Reprint available from:
  Sponheimer M
  Univ Utah, Dept Biol
  Salt Lake City, UT 84112
  USA

Authors
  Benzie IFF.
Title
  Evolution of dietary antioxidants [Review]
Source
  Comparative Biochemistry & Physiology. Part A, Molecular & Integrative
  Physiology. 136(1):113-126, 2003 Sep.
Abstract
  Oxygen is vital for most organisms but, paradoxically, damages key
  biological sites. Oxygenic threat is met by antioxidants that evolved in
  parallel with our oxygenic atmosphere. Plants employ antioxidants to
  defend their structures against reactive oxygen species (ROS; oxidants)
  produced during photosynthesis. The human body is exposed to these same
  oxidants, and we have also evolved an effective antioxidant system.
  However, this is not infallible. ROS breach defences, oxidative damage
  ensues, accumulates with age, and causes a variety of pathological
  changes. Plant-based, antioxidant-rich foods traditionally formed the
  major part of the human diet, and plant-based dietary antioxidants are
  hypothesized to have an important role in maintaining human health. This
  hypothesis is logical in evolutionary terms, especially when we consider
  the relatively hypoxic environment in which humans may have evolved. In
  this paper, the human diet is discussed briefly in terms of its
  evolutionary development, different strategies of antioxidant defence are
  outlined, and evolution of dietary antioxidants is discussed from the
  perspectives of plant need and our current dietary requirements. Finally,
  possibilities in regard to dietary antioxidants, evolution, and human
  health are presented, and an evolutionary cost-benefit analysis is
  presented in relation to why we lost the ability to make ascorbic acid
  (vitamin C) although we retained an absolute requirement for it. (C) 2002
  Elsevier Science Inc. All rights reserved. [References: 68]
Institution
  Reprint available from:
  Benzie IFF
  Hong Kong Polytech Univ, Ageing & Hlth Sect, Fac Hlth & Social Sci
  Kowloon
  Hong Kong
  Peoples R China

Authors
  Eaton SB.
Title
  An evolutionary perspective on human physical activity: implications for
  health [Review]
Source
  Comparative Biochemistry & Physiology. Part A, Molecular & Integrative
  Physiology. 136(1):153-159, 2003 Sep.
Abstract
  At present, human genes and human lives are incongruent, especially in
  affluent Western nations. When our current genome was originally selected,
  daily physical exertion was obligatory; our biochemistry and physiology
  are designed to function optimally in such circumstances. However, today's
  mechanized, technologically oriented conditions allow and even promote an
  unprecedentedly sedentary lifestyle. Many important health problems are
  affected by this imbalance, including atherosclerosis, obesity,
  age-related fractures and diabetes, among others. Most physicians
  recognize that regular exercise is a critical component of effective
  health promotion regimens, but there is substantial disagreement about
  details, most importantly volume: how much daily caloric expenditure, as
  physical activity, is desirable. Because epidemiology-based
  recommendations vary, often confusing and alienating the health-conscious
  public, an independent estimate, arising from a separate scientific
  discipline, is desirable, at least for purposes of triangulation. The
  retrojected level of ancestral physical activity might meet this need. The
  best available such reconstruction suggests that the World Health
  Organization's recommendation, a physical activity level of 1.75 (similar
  to2.1 MJ (490 kcal)/d), most closely approximates the Paleolithic
  standard, that for which our genetic makeup was originally selected. (C)
  2003 Elsevier Science Inc. All rights reserved. [References: 56]
Institution
  Reprint available from:
  Eaton SB
  Emory Univ, Dept Anthropol
  2887 Howell Mill Rd NW
  Atlanta, GA 30327
  USA

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