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  • B N Duncan, J A Logan, I Bey, I A Megretskaia, R M Yantosca, P C Novelli +2 others
  • 2007
[1] We present a model study of carbon monoxide for 1988–1997 using the GEOS-Chem 3-D model driven by assimilated meteorological data, with time-varying emissions from biomass burning and from fossil fuel and industry, overhead ozone columns, and methane. The hydroxyl radical is calculated interactively using a chemical parameterization to capture chemical(More)
This is a report on the demography of the Hadza, a population of East African hunter-gatherers. In it, we describe the results of a census, and our estimation of age structure, survivorship, mean age of women at childbearing, number of live children, total population size and density, and rate of change since 1967. We show that relevant measures fit closely(More)
Humans have a much longer juvenile period (weaning to first reproduction, 14 or more years) than their closest relatives (chimpanzees, 8 years). Three explanations are prominent in the literature. (a) Humans need the extra time to learn their complex subsistence techniques. (b) Among mammals, since length of the juvenile period bears a constant relationship(More)
Long postmenopausal lifespans distinguish humans from all other primates. This pattern may have evolved with mother-child food sharing, a practice that allowed aging females to enhance their daughters' fertility, thereby increasing selection against senescence. Combined with Charnov's dimensionless assembly rules for mammalian life histories, this(More)
In most human foraging societies, the meat of large animals is widely shared. Many assume that people follow this practice because it helps to reduce the risk inherent in big game hunting. In principle, a hunter can offset the chance of many hungry days by exchanging some of the meat earned from a successful strike for shares in future kills made by other(More)
Female postreproductive life is a striking feature of human life history and there have been several recent attempts to account for its evolution. But archaeologists estimate that in the past, few individuals lived many postreproductive years. Is postreproductive life a phenotypic outcome of modern conditions, needing no evolutionary account? This article(More)
Hadza Women's and modern hunter-gatherers and evolutionary ecology, and his publications include ''Ethnoarchaeology Needs a General Theory of Behavior'' Provisioning, and the applying methods, perspectives, and paradigms from animal behavior to research on the behavior of humans. Among his publications are (with K. The present paper was submitted 29 vii 96(More)
Hadza hunter-gatherers display economic and social features usually assumed to indicate the dependence of wives and children on provisioning husbands and fathers. The wives and children of better Hadza hunters have been found to be better-nourished, consistent with the assumption that men hunt to provision their families. Yet, as is common among foragers,(More)
For decades, researchers studying small-scale, subsistence oriented farmers have sought to explain why these " peasants " seem slow to acquire new technologies, novel agricultural practices, and new ideas from the larger societies that have engulfed them. The early work on this question suggested that this " cultural conservatism " resulted from things like(More)