共查询到20条相似文献,搜索用时 15 毫秒
1.
Ruff CB Holt BM Niskanen M Sladék V Berner M Garofalo E Garvin HM Hora M Maijanen H Niinimäki S Salo K Schuplerová E Tompkins D 《American journal of physical anthropology》2012,148(4):601-617
Techniques that are currently available for estimating stature and body mass from European skeletal remains are all subject to various limitations. Here, we develop new prediction equations based on large skeletal samples representing much of the continent and temporal periods ranging from the Mesolithic to the 20th century. Anatomical reconstruction of stature is carried out for 501 individuals, and body mass is calculated from estimated stature and biiliac breadth in 1,145 individuals. These data are used to derive stature estimation formulae based on long bone lengths and body mass estimation formulae based on femoral head breadth. Prediction accuracy is superior to that of previously available methods. No systematic geographic or temporal variation in prediction errors is apparent, except in tibial estimation of stature, where northern and southern European formulae are necessary because of the presence of relatively longer tibiae in southern samples. Thus, these equations should bebroadly applicable to European Holocene skeletal samples. 相似文献
2.
Raxter MH Ruff CB Azab A Erfan M Soliman M El-Sawaf A 《American journal of physical anthropology》2008,136(2):147-155
Trotter and Gleser's (Trotter and Gleser: Am J Phys Anthropol 10 (1952) 469-514; Trotter and Gleser: Am J Phys Anthropol 16 (1958) 79-123) long bone formulae for US Blacks or derivations thereof (Robins and Shute: Hum Evol 1 (1986) 313-324) have been previously used to estimate the stature of ancient Egyptians. However, limb length to stature proportions differ between human populations; consequently, the most accurate mathematical stature estimates will be obtained when the population being examined is as similar as possible in proportions to the population used to create the equations. The purpose of this study was to create new stature regression formulae based on direct reconstructions of stature in ancient Egyptians and assess their accuracy in comparison to other stature estimation methods. We also compare Egyptian body proportions to those of modern American Blacks and Whites. Living stature estimates were derived using a revised Fully anatomical method (Raxter et al.: Am J Phys Anthropol 130 (2006) 374-384). Long bone stature regression equations were then derived for each sex. Our results confirm that, although ancient Egyptians are closer in body proportion to modern American Blacks than they are to American Whites, proportions in Blacks and Egyptians are not identical. The newly generated Egyptian-based stature regression formulae have standard errors of estimate of 1.9-4.2 cm. All mean directional differences are less than 0.4% compared to anatomically estimated stature, while results using previous formulae are more variable, with mean directional biases varying between 0.2% and 1.1%, tibial and radial estimates being the most biased. There is no evidence for significant variation in proportions among temporal or social groupings; thus, the new formulae may be broadly applicable to ancient Egyptian remains. 相似文献
3.
P. Martin Sander Andreas Christian Marcus Clauss Regina Fechner Carole T. Gee Eva‐Maria Griebeler Hanns‐Christian Gunga Jürgen Hummel Heinrich Mallison Steven F. Perry Holger Preuschoft Oliver W. M. Rauhut Kristian Remes Thomas Tütken Oliver Wings Ulrich Witzel 《Biological reviews of the Cambridge Philosophical Society》2011,86(1):117-155
The herbivorous sauropod dinosaurs of the Jurassic and Cretaceous periods were the largest terrestrial animals ever, surpassing the largest herbivorous mammals by an order of magnitude in body mass. Several evolutionary lineages among Sauropoda produced giants with body masses in excess of 50 metric tonnes by conservative estimates. With body mass increase driven by the selective advantages of large body size, animal lineages will increase in body size until they reach the limit determined by the interplay of bauplan, biology, and resource availability. There is no evidence, however, that resource availability and global physicochemical parameters were different enough in the Mesozoic to have led to sauropod gigantism. We review the biology of sauropod dinosaurs in detail and posit that sauropod gigantism was made possible by a specific combination of plesiomorphic characters (phylogenetic heritage) and evolutionary innovations at different levels which triggered a remarkable evolutionary cascade. Of these key innovations, the most important probably was the very long neck, the most conspicuous feature of the sauropod bauplan. Compared to other herbivores, the long neck allowed more efficient food uptake than in other large herbivores by covering a much larger feeding envelope and making food accessible that was out of the reach of other herbivores. Sauropods thus must have been able to take up more energy from their environment than other herbivores. The long neck, in turn, could only evolve because of the small head and the extensive pneumatization of the sauropod axial skeleton, lightening the neck. The small head was possible because food was ingested without mastication. Both mastication and a gastric mill would have limited food uptake rate. Scaling relationships between gastrointestinal tract size and basal metabolic rate (BMR) suggest that sauropods compensated for the lack of particle reduction with long retention times, even at high uptake rates. The extensive pneumatization of the axial skeleton resulted from the evolution of an avian‐style respiratory system, presumably at the base of Saurischia. An avian‐style respiratory system would also have lowered the cost of breathing, reduced specific gravity, and may have been important in removing excess body heat. Another crucial innovation inherited from basal dinosaurs was a high BMR. This is required for fueling the high growth rate necessary for a multi‐tonne animal to survive to reproductive maturity. The retention of the plesiomorphic oviparous mode of reproduction appears to have been critical as well, allowing much faster population recovery than in megaherbivore mammals. Sauropods produced numerous but small offspring each season while land mammals show a negative correlation of reproductive output to body size. This permitted lower population densities in sauropods than in megaherbivore mammals but larger individuals. Our work on sauropod dinosaurs thus informs us about evolutionary limits to body size in other groups of herbivorous terrestrial tetrapods. Ectothermic reptiles are strongly limited by their low BMR, remaining small. Mammals are limited by their extensive mastication and their vivipary, while ornithsichian dinosaurs were only limited by their extensive mastication, having greater average body sizes than mammals. 相似文献
4.
5.
The Maresh reference data on stature and long bone lengths in a sample of healthy middle-class children from Denver, Colorado [Maresh: Am J Dis Child 66 (1943) 227-257; Maresh: Am J Dis Child 89 (1955) 725-742; Maresh: Human growth and development (1970) p 155-200], have been used extensively by biological anthropologists to estimate juvenile age and body size using skeletal elements and to assess growth in skeletal series from different ethnic populations or archaeological cultural groups. How well these data reflect the potentially diverse growth patterns of healthy human populations from different geographic areas is unknown. Similarly, the efficacy of using the Maresh reference data to estimate stunting prevalence in prehistoric populations is unknown. This report presents the results from a comparison of the Maresh data on supine length and standing height to the World Health Organization (WHO) international child growth standard. The WHO growth standard is meant to depict typical human growth under optimal conditions and can be used to assess children worldwide, regardless of ethnicity and socioeconomic status. The results from this comparison indicate that although the Maresh reference data generally conform to the WHO standard, reflecting a normal human growth pattern, and therefore serve as a suitable reference for comparative studies of growth patterns, these reference data are not suitable for estimating stunting prevalence. 相似文献
6.
Clayton E. Cressler William A. Nelson Troy Day Edward McCauley 《Proceedings. Biological sciences / The Royal Society》2014,281(1792)
Parasites often induce life-history changes in their hosts. In many cases, these infection-induced life-history changes are driven by changes in the pattern of energy allocation and utilization within the host. Because these processes will affect both host and parasite fitness, it can be challenging to determine who benefits from them. Determining the causes and consequences of infection-induced life-history changes requires the ability to experimentally manipulate life history and a framework for connecting life history to host and parasite fitness. Here, we combine a novel starvation manipulation with energy budget models to provide new insights into castration and gigantism in the Daphnia magna–Pasteuria ramosa host–parasite system. Our results show that starvation primarily affects investment in reproduction, and increasing starvation stress reduces gigantism and parasite fitness without affecting castration. These results are consistent with an energetic structure where the parasite uses growth energy as a resource. This finding gives us new understanding of the role of castration and gigantism in this system, and how life-history variation will affect infection outcome and epidemiological dynamics. The approach of combining targeted life-history manipulations with energy budget models can be adapted to understand life-history changes in other disease systems. 相似文献
7.
《Chronobiology international》2013,30(3):221-225
Cortisol (CT) concentrations (in mUg/dl) were determined by radioimmunoassay in plasma obtained at about 3-hr intervals during a 24-hr sampling span from 42 boys and 13 girls of short stature (2–4 standard deviations below their peer group mean), and from a reference group of 11 boys and 10 girls with standard stature, before any treatment were administered to the former. Subjects were 11.20 0.37 years of age at the time of study, and were living on a diurnal waking (~07:30 to ~22:30), nocturnal resting routine during sampling, consuming the usual hospital diet. Circadian rhythm parameters were computed separately for each group by the single and population-mean cosinor Tits of a 24-hr cosine curve. A comparison of circadian parameters indicates a statistically significant difference in acrophase (>P =0.033) between short and standard children, as well as added differences in rhythm-adjusted mean (M; P=0.011) and (P =0.035) between boys and girls of short stature. These differences, as well as any other added information from relevant marker rhythms, should be taken into account for the time-specification of therapy before treatment starts in children of short stature. 相似文献
8.
H.K. Kurki J.K. Ginter J.T. Stock S. Pfeiffer 《American journal of physical anthropology》2010,141(2):169-180
Body size (stature and mass) estimates are integral to understanding the lifeways of past populations.Body size estimation of an archaeological skeletal sample can be problematic when the body size or proportions of the population are distinctive. One such population is that of the Holocene Later Stone Age (LSA) of southern Africa, in which small stature (mean femoral length = 407 mm, n = 52) and narrow pelves (mean bi‐iliac breadth = 210 mm, n = 50) produce a distinctive adult body size/shape, making it difficult to identify appropriate body size estimation methods. Material culture, morphology, and culture history link the Later Stone Age people with the descendant population collectively known as the Khoe‐San. Stature estimates based on skeletal “anatomical” linear measures (the Fully method) and on long bone length are compared, along with body mass estimates derived from “morphometric” (bi‐iliac breath/stature) and “biomechanical” (femoral head diameter) methods, in a LSA adult skeletal sample (n = 52) from the from coastal and near‐coastal regions of South Africa. Indices of sexual dimorphism (ISD) for each method are compared with data from living populations. Fully anatomical stature is most congruent with Olivier's femur + tibia method, although both produce low ISD. McHenry's femoral head body mass formula produces estimates most consistent with the bi‐iliac breadth/staturemethod for the females, although the males display higher degrees of disagreement among methods. These results highlight the need for formulae derived from reference samples from a wider range of body sizes to improve the reliability of existing methods. Am J Phys Anthropol, 2010. © 2009 Wiley‐Liss, Inc. 相似文献
9.
Summary Experiments were conducted in the Patagonian steppe in southern South America to test the following hypotheses: (a) grasses take up most of the water from the upper layers of the soil and utilize frequent and short-duration pulses of water availability; (b) shrubs, on the contrary, take up most of the water from the lower layers of the soil and utilize infrequent and long-duration pulses of water availability. Grasses and shrubs were removed selectively and the performance of plants and the availability of soil resources were monitored. Results supported the overall hypothesis that grasses and shrubs in the Patagonian steppe use mainly different resources. Removal of shrubs did not alter grass production but removal of grasses resulted in a small increase in shrub production which was mediated by an increase in deep soil water and in shrub leaf water potential. The efficiency of utilization of resources freed by grass removal was approximately 25%. Shrubs used water exclusively from lower soil layers. Grasses took up most of the water from upper layers but they were also capable of absorbing water from deep layers. This pattern of water partitioning along with the lack of response in leaf nitrogen to the removal treatments suggested that shrubs may be at a disadvantage to grasses with respect to nutrient capture and led to questions about the role of nutrient recirculation, leaching, and nitrogen fixation in the steppe. 相似文献
10.
Water‐limited ecosystems have undergone rapid change as a consequence of changing land use and climate. The consequences of these changes on soil quality and vegetation dynamics have been documented in different regions of the world. In contrast, their effects on soil water, the most limiting resource in these environments, have received less attention, although in recent years increasing efforts have been made to relate grazing, soil water and vegetation functioning. In this paper, we present the results of field observations of plant phenology and soil water content carried out during two successive years at four sites along a degradation gradient caused by grazing in the Patagonian Monte, Argentina. We also developed a simplified soil water balance model to evaluate how changes in plant cover could affect water balance. Our field observations showed that the soil water content in the soil layer where roots of grasses are abundant (0–25 cm) was higher and the growing cycles were longer in degraded than in preserved sites. Similarly, our modelling approach showed that the deep soil (depth > 10 cm) was wetter in the degraded than in the preserved situation. Simulation also suggested a switch from transpiration to a direct evaporation dominance of water losses with degradation. Although reductions in plant cover related to grazing degradation were associated with a decrease in annual transpiration, the simulated soil water loss by transpiration was higher during summer in the degraded than in the well preserved situation. Thus, our field observations seem to be a consequence of ecohydrological changes causing an accumulation of water in the soil profile during the cold season and its transpiration during summer. In conclusion, our results showed that changes in plant cover caused by grazing disturbance can alter the soil water balance, which in turn can affect vegetation function. 相似文献
11.
D. E. Ayala R. C. Hermida L. Garciat T. Iglesias C. Lodeiro 《Chronobiology international》1990,7(3):217-220
Growth hormone (GH) concentrations (in ng/ml) were determined by radioimmunoassay, in plasma obtained at about 3-hr intervals during a 24-hr sampling span, from 42 boys and 12 girls of short stature (2-4 standard deviations below their peer group mean), and 13 boys and 9 girls of standard stature. Subjects had 11.20 0.37 years of age at the time of study, and were living on a diurnal waking (∼07:30 to ∼22:30), nocturnal resting routine during sampling. Analysis of these data by single and population-mean cosinor methods as well as by analysis of variance revealed circadian and ultradian prominent components characterizing most groups. Accordingly, a multiple component analysis was undertaken for data of each group separately, as well as for all subjects. A comparison of circadian parameters indicates similar characteristics between short and standard children, whether one compares boys [P=0.674, 0.371 and 0.749 for comparison of rhythm adjusted means (M), amplitudes (A) and acrophases (), respectively], girls (P=0.993,0.914 and 0.397), or all children (P=0.859,0.712 and 0.865). Differences are found, however, in circasemidian characteristics as well as in the prominent 8-hr ultradian component documented for the short but not for the standard children. These ultradian components should be taken into consideration in the design and later evaluation of a time-specified treatment of children of short stature. 相似文献
12.
Stature (height) is an important factor in establishing the identity of a person in the living as well as in the skeletonized state. When stature is estimated from the bones of the limbs, regression equations, which estimate the ratios of the lengths of bones to the height of the individual, are generated. The majority of bones that were used previously were the long bones. The calcaneus was used for estimating stature only in American whites and blacks (Holland [1995] Am. J. Phys. Anthropol. 96:315-320). The regression equations that he generated were found to be useful for stature estimation in these population groups. Since the calcaneus has not been used for the same purpose in South Africa, the aim of this study was to derive regression equations that will allow this bone to be used for stature estimation in South African blacks. In total, 116 complete skeletons (60 males and 56 females) were selected from the Raymond A. Dart Collection of Human Skeletons, School of Anatomical Sciences, University of the Witwatersrand (Johannesburg, South Africa). The skeletal heights of these sets of skeletons were calculated using the anatomical method of Fully ([1956] Ann. Med. Leg. 35:266-273). Nine parameters of the calcaneus were measured and matched against skeletal heights, using univariate and multivariate regression methods. Regression equations were obtained for estimation of the stature of the South African black population from the calcaneus. The standard error of estimate that was obtained with univariate regression analysis was higher than the corresponding values using multivariate regression analysis. In both cases, the standard errors of estimate compared well with the values obtained for fragmentary long bones by previous authors. 相似文献
13.
14.
Markku Niskanen Heli Maijanen Donna McCarthy Juho‐Antti Junno 《American journal of physical anthropology》2013,152(1):96-106
This study focuses on the age adjustment of statures estimated with the anatomical method. The research material includes 127 individuals from the Terry Collection. The cadaveric stature (CSTA)–skeletal height (SKH) ratios indicate that stature loss with age commences before SKH reduction. Testing three equations to estimate CSTA at the age at death and CSTA corrected to maximum stature from SKH indicates that the age correction of stature should reflect the pattern of age‐related stature loss to minimize estimation error. An equation that includes a continuous and linear age correction through the entire adult age range [Eq. (1)] results in curvilinear stature estimation error. This curvilinear stature estimation error can be largely avoided by applying a second linear equation [Eq. (2)] to only individuals older than 40 years. Our third equation [Eq. (3)], based on younger individuals who have not lost stature, can be used to estimate maximum stature. This equation can also be applied to individuals of unknown or highly uncertain age, because it provides reasonably accurate estimates until about 60/70 years at least for males. Am J Phys Anthropol 152:96–106, 2013. © 2013 Wiley Periodicals, Inc. 相似文献
15.
16.
Phylogenetic position and composition of Zygiellinae and Caerostris,with new insight into orb‐web evolution and gigantism 下载免费PDF全文
Matjaž Gregorič Ingi Agnarsson Todd A. Blackledge Matjaž Kuntner 《Zoological Journal of the Linnean Society》2015,175(2):225-243
Orb‐weaving spiders are good objects for evolutionary research, but phylogenetic relationships among and within orb‐weaving lineages are poorly understood. Here we present the first species‐level molecular phylogeny that includes the enigmatic orb weavers ‘Zygiellidae’ and Caerostris. Zygiellidae is interesting for the evolution of the sector web, and Caerostris is noteworthy for web gigantism and extraordinary silk biomechanics. We assembled a molecular data set using mitochondrial (COI, 16S) and nuclear (H3, 18S, 28S, ITS2) gene fragments for 112 orbicularian exemplars, focusing on taxa with diverse web architecture and size. We show that ‘Zygiellidae’ contains the Holarctic Zygiella genus group (Leviellus, Parazygiella, Stroemiellus, and Zygiella) and the Australasian Phonognatha and Deliochus. As this clade is placed with Araneidae in all analyses we treat it as a subfamily, Zygiellinae. Using the new phylogeny, we show that the sector web evolved eight times, and coevolved with the silk tube retreat, but that these features are not zygielline synapomorphies. Zygiellinae, Caerostris, and some other araneids form a basal grade of araneids that differ from ‘classical’ araneids in web‐building and preying behaviour. We also confirm that Caerostris represents the most striking case of spider‐web gigantism. © 2015 The Linnean Society of London 相似文献
17.
Extant chelonians (turtles and tortoises) span almost four orders of magnitude of body size, including the startling examples of gigantism seen in the tortoises of the Galapagos and Seychelles islands. However, the evolutionary determinants of size diversity in chelonians are poorly understood. We present a comparative analysis of body size evolution in turtles and tortoises within a phylogenetic framework. Our results reveal a pronounced relationship between habitat and optimal body size in chelonians. We found strong evidence for separate, larger optimal body sizes for sea turtles and island tortoises, the latter showing support for the rule of island gigantism in non-mammalian amniotes. Optimal sizes for freshwater and mainland terrestrial turtles are similar and smaller, although the range of body size variation in these forms is qualitatively greater. The greater number of potential niches in freshwater and terrestrial environments may mean that body size relationships are more complicated in these habitats. 相似文献
18.
In arid environments, the high availability of sunlight due to the scarcity of trees suggests that plant competition take place mainly belowground for water and nutrients. However, the occurrence of soil disturbances that increase nutrient availability and thereby promote plant growth may enhance shoot competition between neighboring plants. We conducted a greenhouse experiment to evaluate the influence of the enriched soil patches generated by the leaf-cutting ant, Acromyrmex lobicornis, on the performance of the alien forb Carduus thoermeri (Asteraceae) under different intraspecific competition scenarios. Our results showed that substrate type and competition scenario affected mainly aboveground plant growth. As expected, plants growing without neighbors and in nutrient-rich ant refuse dumps showed more aboveground biomass than plants growing with neighbors and in nutrient-poor steppe soils. However, aboveground competition was more intense in nutrient-poor substrates: plants under shoot and full competition growing in the nutrient-rich ant refuse dumps showed higher biomass than those growing on steppe soils. Belowground biomass was similar among focal plants growing under different substrate type. Our results support the traditional view that increments in resource availability reduce competition intensity. Moreover, the fact that seedlings in this sunny habitat mainly compete aboveground illustrates how limiting factors may be scale-dependent and change in importance as plants grow. 相似文献
19.
Maria Eugenia De Porras Maria Virginia Mancini Aldo Raul Prieto 《Vegetation History and Archaeobotany》2009,18(3):235-244
Vegetation changes during the late Holocene are interpreted from four fossil pollen sequences from two caves at the Los Toldos archaeological locality, Santa Cruz province, Argentina. Taphonomic processes are particularly taken into account in order to analyze the effects on the fossil pollen records of biotic factors such as human occupation and animals, and abiotic ones such as volcanic ash fall. Fossil pollen assemblages are interpreted using local modern pollen data. The main vegetation change occurred at ca. 3750 uncal b.p., when a shrub steppe of Asteraceae subf. Asteroideae with Schinus, Ephedra frustillata and a high proportion of grasses was replaced by a shrub steppe of Colliguaja integerrima and Asteraceae subf. Asteroideae. This change is synchronous with an archaeological record change and could be related either to moderate climatic variations or the effects of ash fall on the environment. Plant communities similar to the present-day ones were established in the Los Toldos area from ca. 3750 uncal b.p. 相似文献
20.
D. M. MOORE F.L.S. 《Botanical journal of the Linnean Society. Linnean Society of London》1978,77(3):177-202
By comparison with the major modern plant communities of southern Patagonia, the changing post-glacial vegetation of the region is reconstructed from macrofossils derived from deposits in the Cueva del Mylodon, Ultima Esperanza, S. Chile. The oldest deposits, carbon-dated as c. 12,400 B.P., comprise dung of the extinct ground sloth Mylodon darwinii and show the animal to have fed entirely on Cyperaceae, Gramineae and species associated with these in the modern cool, wet sedge-grasslands of western Patagonia, communities which would be expected after the retreat of the ice. Overlying deposits of well-preserved, wind-blown leaf-litter permitted some quantitative analyses which show a rise of evergreen forest dominated by Nothofagus betuloides that reached its maximum c. 7000 B.P. and then declined as it was replaced by deciduous N. pumilio forest. A break in the fossil plant record, covering the human occupation about 5643 B.P. and the subsequent final appearance of Mylodon remains, is followed by evidence of mixed evergreen/deciduous forest in which Nothofagus pumilio gradually increases in importance to give deciduous forest some 2500 years ago similar to that found in the environs of the cave in historical times. Comparison with pollen diagrams shows that the modern climatic and vegetation difference between E. Fudgia and Ultima Eeperanza has persisted throughout the post-glacial period. 相似文献