American journal of physical anthropology
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Am. J. Phys. Anthropol. · Jan 2009
ReviewReproductive ecology and the endometrium: physiology, variation, and new directions.
Endometrial function is often overlooked in the study of fertility in reproductive ecology, but it is crucial to implantation and the support of a successful pregnancy. Human female reproductive physiology can handle substantial energy demands that include the production of fecund cycles, ovulation, fertilization, placentation, a 9-month gestation, and often several years of lactation. The particular morphology of the human endometrium as well as our relative copiousness of menstruation and large neonatal size suggests that endometrial function has more resources allocated to it than many other primates. ⋯ In this review, I will describe endometrial physiology, methods of measurement, variation, and some of the ecological variables that likely produce variation and pregnancy losses to demonstrate the necessity of further study. I propose several basic avenues of study that leave room for testable hypotheses in the field of reproductive ecology. And finally, I describe the potential of this work not just in reproductive ecology, but in the resolution of broader women's health issues.
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Mummies are human remains with preservation of nonbony tissue. Mummification by natural influences results in so-called natural mummies, whereas mummification induced by active (human) intervention results in so-called artificial mummies, although many cultures practiced burial rites, which to some degree involved both natural and artificial mummification. Since they are so uniquely well-preserved, mummies may give many insights into mortuary practices and burial rites. ⋯ A description of the extant key technologies of natural and medical science that are applied in mummy studies is given; along with a discussion of some of the major results in terms of paleopathology. It is also shown how mummy studies have contributed much to the knowledge of the cultural habits and everyday life of past populations. Finally the impact of mummy studies on analyses of mortuary practices and cultural history is discussed.
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Am. J. Phys. Anthropol. · Jan 2002
ReviewInterpreting the posture and locomotion of Australopithecus afarensis: where do we stand?
Reconstructing the transition to bipedality is key to understanding early hominin evolution. Because it is the best-known early hominin species, Australopithecus afarensis forms a baseline for interpreting locomotion in all early hominins. While most researchers agree that A. afarensis individuals were habitual bipeds, they disagree over the importance of arboreality for them. ⋯ The apparent stasis in Australopithecus postcranial form is currently the strongest evidence for stabilizing selection maintaining its primitive features. Evidence from features affected by individual behaviors during ontogeny shows that A. afarensis individuals were habitually traveling bipedally, but evidence presented for arboreal behavior so far is not conclusive. By clearly identifying the questions we are asking about early hominin fossils, refining our knowledge about character polarities, and elucidating the factors influencing morphology, we will be able to progress in our understanding of the posture and locomotion of A. afarensis and all early hominins.
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Am. J. Phys. Anthropol. · Jan 2001
ReviewA proper study for mankind: Analogies from the Papionin monkeys and their implications for human evolution.
This paper's theme is that analogies drawn from the cercopithecine tribe Papionini, especially the African subtribe Papionina (baboons, mangabeys, and mandrills), can be a valuable source of insights about the evolution of the human tribe, Hominini, to complement homologies found in extant humans and/or African apes. Analogies, involving a "likeness of relations" of the form "A is to B, as X is to Y," can be usefully derived from nonhomologous (homoplastic) resemblances in morphology, behavior, ecology, or population structure. Pragmatically, the papionins are a fruitful source of analogies for hominins because they are phylogenetically close enough to share many basic attributes by homology, yet far enough that homoplastic modifications of these features are easily recognized as such. ⋯ Neandertals and Afro-Arabian "premodern" populations may have been analogous to extant baboon (and macaque) allotaxa: "phylogenetic" species, but "biological" subspecies. "Replacement," in Europe, probably involved a rapidly sweeping hybrid zone, driven by differential population pressure from the "modern" side. Since the genetic outcome of hybridization at allotaxon boundaries is so variable, the problem of whether any Neandertal genes survived the sweep, and subsequent genetic upheavals, is a purely empirical one; if any genes passed "upstream" across the moving zone, they are likely to be those conferring local adaptive advantage, and markers linked to these. In general, extant papionin analogies suggest that the dynamics and interrelationships among hominin populations now known only from fossils are likely to have been more complex than we are likely to be able to discern from the evidence available, and also more complex than can be easily expressed in conventional taxonomic terminology.