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Hair removed from archaeological burials can tell us a lot about the diet and lifestyle of our ancestors--information that may survive because of the unique biology of hair formation. But hair is also biodegradable and the effects of time and burial conditions can result in conflicting evidence of past lives.  相似文献   

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Archaeological data are frequently cited in support of the idea that big game hunting drove the evolution of early Homo, mainly through its role in offspring provisioning. This argument has been disputed on two grounds: (1) ethnographic observations on modern foragers show that although hunting may contribute a large fraction of the overall diet, it is an unreliable day-to-day food source, pursued more for status than subsistence; (2) archaeological evidence from the Plio-Pleistocene, coincident with the emergence of Homo can be read to reflect low-yield scavenging, not hunting. Our review of the archaeology yields results consistent with these critiques: (1) early humans acquired large-bodied ungulates primarily by aggressive scavenging, not hunting; (2) meat was consumed at or near the point of acquisition, not at home bases, as the hunting hypothesis requires; (3) carcasses were taken at highly variable rates and in varying degrees of completeness, making meat from big game an even less reliable food source than it is among modern foragers. Collectively, Plio-Pleistocene site location and assemblage composition are consistent with the hypothesis that large carcasses were taken not for purposes of provisioning, but in the context of competitive male displays. Even if meat were acquired more reliably than the archaeology indicates, its consumption cannot account for the significant changes in life history now seen to distinguish early humans from ancestral australopiths. The coincidence between the earliest dates for Homo ergaster and an increase in the archaeological visibility of meat eating that many find so provocative instead reflects: (1) changes in the structure of the environment that concentrated scavenging opportunities in space, making evidence of their pursuit more obvious to archaeologists; (2) H. ergaster's larger body size (itself a consequence of other factors), which improved its ability at interference competition.  相似文献   

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Archaea are prokaryotes that evolved in parallel with bacteria. Since the discovery of the distinct status of the Archaea, extensive physiological and biochemical research has been conducted to elucidate the molecular basis of their remarkable lifestyle and their unique biology. Here, we discuss how in-depth comparative genomics has been used to improve the annotation of archaeal genomes. Combined with experimental verification, bioinformatic analysis contributes to the ongoing discovery of novel metabolic conversions and control mechanisms, and as such to a better understanding of the intriguing biology of the Archaea.  相似文献   

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The successful preparation of an active remnant of Cu,Zn-superoxide dismutase from mummified brain tissue stimulated the isolation of both biochemically and immunologically active alkaline Zn2Mg-phosphatase from antique bone samples of different archaeological sites and age. In particular, specimens from pharaonic Egypt being up to 4000 years of age were used. Gel filtration, ion exchange and affinity chromatographies were employed to optimise the preparation of the ancient enzyme. Compared to the specific activity of alkaline phosphatase from modern autopsy some 50% for a Ptolemaic and 10% for the Old Kingdom enzyme was detectable. The possibility of microbial contamination was checked by employing specific monoclonal antibodies directed against the human bone enzyme. Fortunately, ubiquitously present specified microorganisms on the respective ancient bones did not cross-react with these antibodies while the ancient metalloenzyme reacted with high specificity. Alkaline phosphatase mimicks could be excluded as in the presence of the inhibitors 1,10-phenanthroline and L-homoarginine the enzyme activity was diminished. The presence of ortho-vanadate as a substrate analogon abolished the catalytic function of the enzyme. Likewise, heating to 100 degrees C and replacement of zinc(II) by cadmium(II) resulted in a dramatic loss of activity. In conclusion, alkaline phosphatase appears to be a useful marker enzyme in molecular archaeology.  相似文献   

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This essay reviews Iain Morley’s The Prehistory of Music, an up-to-date and authoritative overview of recent research on evolution and cognition of musicality from an interdisciplinary viewpoint. Given the diversity of the project explored, integration of evidence from multiple fields is particularly pressing, required for any novel evolutionary account to be persuasive, and for the project’s continued progress. Moreover, Morley convincingly demonstrates that there is much more to understanding musicality than is supposed by some theorists. I outline Morley’s review of the archaeological and ethnographic literature, and then go on to critique his assessment of philosophical and evolutionary theories, offering some alternative perspectives that might better benefit his project.  相似文献   

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Archaeological research in the Australia's northeast Queensland rainforest and margins has revealed a human antiquity of at least 8000 cal year BP within the rainforest and at least 30,000 years on the western edge. Rainforest occupation before 2000 cal year BP was at generally very low levels, after which time settlement of this environment became intensive and probably permanent. Exploitation of toxic varieties of nuts began about 2500 cal year BP, peaking after 1500 cal year BP. This economic development appears crucial to successful human adaptation to rainforests in the area and was pivotal in facilitating the long-term permanent human settlement of the wet tropics. The role of fire, El Niño Southern Oscillation (ENSO) activity and shifting vegetation regimes were important catalysts in providing opportunities for permanent Australian rainforest Aboriginal occupation. The results have implications for global understandings of rainforest occupation by modern people. It demonstrates the wide temporal and spatial variability of human rainforest colonization processes worldwide.  相似文献   

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Summary We develop a stepwise model for the net transfer of nucleic acid sequences between nonhomologous genomes. This model is then used to explain the two major patterns in the evolutionary history of mitochondrial genomes: the gross reduction of the number of genes, and the subsequent acquisition of introns.  相似文献   

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Over 70 pollen types were recovered from honey samples from eight localities in southern Nigeria. The identified honey pollen are those of important climatic and environmental indicator species, and clearly reflect the botanical and geographical origins of the honey samples. The implications of this in the study of past environments and archaeology are discussed.  相似文献   

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Literature on sperm competition in the Acari is reviewed and supplemented with the author's unpublished observations. As in other animals, morphology and physiology of the female reproductive tract are key factors establishing the sperm competition pattern. First-male sperm priority was found in Gamasida and Actinedida, whereas in Acaridida the last males to mate had the highest reproductive success. However, this general pattern may be modified by behavioural factors, and another aspect needs scrutiny: in many groups of mites sperm cells follow routes other than the lumen of the reproductive tract to meet and fertilize the oocyte. The Acari are a very promising group for future research because of the wide range of sperm competition patterns, accompanied by great diversity in reproductive morphology, physiology and mating.  相似文献   

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The present paper addresses the tensions between internalist and radical-interactionist approaches to cognitive neuroscience, and the conflicting conclusions these positions lead to as regards the issue of whether archaeological artefacts constitute 'results' or 'components' of cognition. Wild systems theory (WST) and the notion of wild agency are presented as a potential resolution. Specifically, WST conceptualizes organisms (i.e. wild agents) as open, multi-scale self-sustaining systems. It is thus able to address the causal properties of wild systems in a manner that is consistent with radical-interactionist concerns regarding multi-scale contingent interactions. Furthermore, by conceptualizing wild agents as self-sustaining embodiments of the persistent, multi-scale contexts that afforded their emergence and in which they sustain themselves, WST is able to address the semantic properties of wild agents in a way that acknowledges the internalist concerns regarding meaningful (i.e. semantic) internal states (i.e. causal content). In conclusion, WST agrees with radical interactionism and asserts that archaeological artefacts constitute components of cognition. In addition, given its ability to resolve tensions between the internalist and the radical interactionist approaches to cognition, WST is presented as potentially integrative for cognitive science in general.  相似文献   

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Host race formation generates diversity within species and may even lead to speciation. This phenomenon could be particularly prevalent in the Acari due to the often intimate interaction these species have with their hosts. In this review, we explore the process of host race formation, whether it is likely to occur in this group and what features may favour its evolution. Although few studies are currently available and tend to be biased toward two model species, results suggest that host races are indeed common in this group, and more likely to occur when hosts are long-lived. We discuss future directions for research on host-associated adaptations in this group of organisms and the potential relevance of host race formation for the biodiversity of mites and ticks.  相似文献   

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