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1.
Excavation at the Ecuadorian highland site of La Florida in suburban Quito revealed six deep shaft tombs yielding high-status individuals (n = 9) as well as apparent sacrifices and other low-status individuals (n = 23). Determination of sex and age at death of the recovered skeletal remains resulted in a sample of 32 individuals aged from approximately 7 to 50 years of age. The sample of 18 individuals over the age of 18 years included 14 females and 4 males. Temporally, the remains are assigned to the Chaupicruz Phase (circa 100 to 450 AD) of the Regional Developmental Period. In this study, we analyze stable isotopes of carbon and nitrogen from human bone in order to compare the diets of the high- and low-status individuals. Stable carbon isotope analyses were carried out on preserved protein and biological apatite (bioapatite), and stable nitrogen isotope analyses were carried out on preserved protein. There is a statistically significant difference in δ13C between the two groups for both protein and mineral sources of carbon with evidence for the greater consumption of maize in the high-status group. There is no significant difference in δ15N between the two groups, nor is there a significant difference in the spacing between protein and mineral δ13C values between the two groups. Ethnohistorical evidence for the 16th century AD provides the expectation that the only dietary difference was the higher consumption of animal protein by the elite. There is no evidence for this based on the bone chemistry data from La Florida. Instead, the isotope data, along with the archaeological evidence, indicate that the major dietary difference during the Chaupicruz Phase was the greater intake of maize by the elite, probably in the form of beer (chicha). © 1995 Wiley-Liss, Inc.  相似文献   

2.
This paper tests the Trivers-Willard hypothesis that high-status individuals will invest more in sons and low-status individuals will invest more in daughters using data from the 2000 to 2010 General Social Survey and the 1979 National Longitudinal Survey of Youth. We argue that the primary investment U.S. parents make in their children is in their children’s education, and this investment is facilitated by a diverse market of educational choices at every educational level. We examine two measures of this investment: children’s years of education and the highest degree attained. Results show that sons of high-status fathers receive more years of education and higher degrees than daughters, whereas daughters of low-status fathers receive more years of education and higher degrees than sons. Further analyses of possible mechanisms for these findings yield null results. We also find that males are more likely to have high-status fathers than females.  相似文献   

3.
Dental caries and antemortem tooth loss (AMTL) are investigated in a Classic Maya sample obtained from the sites of Calakmul, Dzibanché, and Kohunlich (Mexico). This study aims at assessing the effect that sex and social status had on the prevalence of oral pathologies. The lack of a direct relationship between caries, AMTL, and age-at-death led us to interpret the results in terms of the biological, socioeconomic, and behavioral conditions prevailing in these ancient Maya settlements. Benefits related to sex and social status are evident in the frequency of carious lesions, which appear less frequently in elite males than in low-status individuals of both sexes and in elite females. Individuals from problematic mortuary contexts and isolated bone assemblages, who could not be ascribed to any status group, showed the highest rates of caries. Sex discrimination in dietary preferences appears in the elite sample, while the homogeneity encountered between sexes in the low-status segment suggests a more uniform access to resources. Tooth loss clearly distinguishes elite individuals from commoners, regardless of sex, with the former bearing a much higher rate of loss. In individuals from the undefined mortuary assemblages and sacrificial contexts, it was even more pronounced than in the other groups, although its interpretation is problematic due to a lack of associated funerary data. The overall evidence from oral pathologies is interpreted to be the result of deficient oral hygiene coupled with a softer and more refined diet in the high-status population, particularly males. Whereas elite males' subsistence was apparently based more on animal proteins and relatively soft and refined foods, a diet relying on carbohydrates may account for the observed rate of oral pathologies in elite females and commoners.  相似文献   

4.
正偏好行为被认为是研究大脑半球功能偏侧性调控表达的一种预测指标(Elias et al.,1998)。偏好行为与大脑解剖结构和功能不对称之间关系的研究表明人类明显偏爱使用右手,是由大脑左半球控制(Zhao et al.,2010;崔媛媛,2012;付卫伟,2012),而手偏好正是大脑皮层结构和功能不对称最基本的行为表现,是大脑半球特化的一个行为标  相似文献   

5.
The varied relationships among status, gender, and mortality are complex, historically produced phenomena that shape people's lives and deaths in socially meaningful ways. Paleodemographic analysis coupled with acute sensitivity to site-specific context has the potential to move us toward a greater understanding of these experiences in the past. After considering the potential effects of migration and fertility on the age-at-death profiles of adult individuals interred at the Gilbertine Priory of St. Andrew, Fishergate, York (n = 200), it is asserted that these profiles primarily reveal expected and unexpected relationships among status, gender, and mortality in this Medieval context. Collectively, the long lives of religious-status males compared to other composite and gendered status groups suggest that they experienced a relatively comfortable existence despite periodic complaints of destitution. The postulated demographic advantage of high-status males did not materialize in the analysis, and a reevaluation of the skeletal evidence indicates that nearly 20% of these individuals died violently. Unexpectedly, moderate-status females shared a mortality profile similar to that of religious-status males and retained a demographic advantage over all other secular status groups. In contrast to the experiences of moderate-status females, low-status females had, on average, the shortest lives at St. Andrew's. This pattern is intimately linked to their restriction from crucial social and economic resources, and provides further evidence of their marginalization in York's wage-labor economy. Overall, these relationships suggest that traditional, highly stratified and gendered notions of Medieval status and mortality are not adequate for understanding the intricacies of everyday life and death at St. Andrew's.  相似文献   

6.
Research examining face-to-face status hierarchies suggests that individuals attain respect and admiration by engaging in behavior that influences others'' judgments of their value to the group. Building on this research, we expected that high-status individuals would be less likely to engage in behaviors that violate group norms and expectations, relative to low-status individuals. Adolescent participants took part in an interaction in which they teased an opposite-gender friend (Study 1) or an experiment in which taunting or cheering expectations were manipulated (Study 2). Consistent with the hypothesis, high-status boys and girls engaged in teasing behaviors consistent with their gender roles, relative to their low status counterparts (Study 1). In Study 2, high-status boys engaged in more direct provocation and off-record commentary while taunting, and more affiliative behavior while cheering on their partner, relative to low-status boys. Discussion focused on how expectation-consistent actions help individuals maintain elevated status.  相似文献   

7.
Stable isotope ratios (δ13C and δ15N) were measured in human burials from the post‐medieval (16th–18th c. AD) Carmelite friary burial grounds at Aalst, a town in Flanders, Belgium. Dietary patterns of 39 adult individuals were analyzed, from a mixed monastic and lay population buried in three different locations, reflecting groups with differing social status. The data show significant variation in the consumption of perhaps meat, but certainly also marine protein between females and males. This result represents a remarkable continuity with medieval dietary patterns, suggesting that the social and economic changes of the early modern period had a limited effect on everyday life. When both sexes were examined together, individuals buried in the cloister garth consumed significantly less marine protein compared to people buried in the church, likely reflecting social stratification. No statistical differences were observed between isotopic values from the church and the cloister alley, suggesting a similarly diverse diet of the monastic part of the buried population and that of the richer lay population. Finally, the hypothesis that diffuse idiopathic skeletal hyperostosis (DISH) is linked to a diet rich in animal protein was tested. No systematic or statistically significant differences between pathological and non‐pathological bones from the same individuals affected with DISH were observed, and no statistical differences were found between individuals with DISH and individuals without DISH. Am J Phys Anthropol 153:203–213, 2014. © 2013 Wiley Periodicals, Inc.  相似文献   

8.
Courtship varies among individuals, partly because individuals differ in quality. To explore proximate factors affecting courtship behavior, I investigated the effect of diet quality on mate choice and competition in the barklouseLepinotus patruelis Pearman (Psocoptera: Trogiidae) in the laboratory. The effect of sex ratio on mate choice was also addressed. Some males were found to exhibit active mate choice, and rejected females in both male- and female-biased sex ratio groups, although they were more likely to do so in a female-biased sex ratio group. Diet quality affected male mate choice: males on high-quality diets were significantly more likely to reject females than males on low-quality diets. Males exhibited choice significantly more often than females, who showed no overt signs of choosiness. Both males and females competed for, access to mates: both sexes attempted to interfere with mounted pairs and females grappled. The choosiness of the male may have directly affected the incidence of female competition. The results also suggest that the patterns of mate choice inL. patruelis differ from those expected by conventional sex role theory.  相似文献   

9.
Sexually dimorphic brain volumes (sexually dimorphic nucleus of the preoptic area (SDN-POA) and anteroventral periventricular (AVPV) nucleus) are influenced by estrogens. Phytoestrogens, derived from plants (especially soy products), are molecules structurally and functionally similar to estradiol. The purpose of this study was to examine: the consumption of phytoestrogen (using a phytoestrogen-rich (Phyto-600) versus a phytoestrogen-free (Phyto-free)) diets from conception to adulthood (or changing the diets during adulthood) and characterizing (a) circulating plasma phytoestrogen levels, (b) testosterone levels in males, (c) sexually dimorphic brain volumes (i.e. the SDN-POA and AVPV) and (d) the presence of apoptotic cells in these brain structures in Long-Evans rats. Phyto-600 fed animals displayed total serum phytoestrogens levels 37-fold higher compared to Phyto-free values. Circulating testosterone levels were not significantly altered by the diets. Female SDN-POA volumes were not altered by the diets. Whereas, males fed a Phyto-free diet displayed decreased SDN-POA volumes compared to male Phyto-600 values. Females fed the Phyto-600 diet displayed larger AVPV volumes compared to males on the same diet or females on the Phyto-free diet. Males fed the Phyto-free diet had the largest AVPV values compared to Phyto-600 fed males. When the SDN-POA region was examined in lifelong Phyto-free fed males, apoptotic cells were present versus males fed the Phyto-600 diet and in the AVPV region the opposite results were obtained. In summary, consumption of dietary phytoestrogens (estrogen mimics) can alter hormone-sensitive hypothalamic brain volumes in rodents during adulthood.  相似文献   

10.
Genetic, ethnographic, and historical evidence suggests that the Hindu castes have been highly endogamous for several thousand years and that, when movement between castes does occur, it typically consists of females joining castes of higher social status. However, little is known about migration rates in these populations or the extent to which migration occurs between caste groups of low, middle, and high social status. To investigate these aspects of migration, we analyzed the largest collection of genetic markers collected to date in Hindu caste populations. These data included 45 newly typed autosomal short tandem repeat polymorphisms (STRPs), 411 bp of mitochondrial DNA sequence, and 43 Y-chromosomal single-nucleotide polymorphisms that were assayed in more than 200 individuals of known caste status sampled in Andrah Pradesh, in South India. Application of recently developed likelihood-based analyses to this dataset enabled us to obtain genetically derived estimates of intercaste migration rates. STRPs indicated migration rates of 1–2% per generation between high-, middle-, and low-status caste groups. We also found support for the hypothesis that rates of gene flow differ between maternally and paternally inherited genes. Migration rates were substantially higher in maternally than in paternally inherited markers. In addition, while prevailing patterns of migration involved movement between castes of similar rank, paternally inherited markers in the low-status castes were most likely to move into high-status castes. Our findings support earlier evidence that the caste system has been a significant, long-term source of population structuring in South Indian Hindu populations, and that patterns of migration differ between males and females.  相似文献   

11.
1. Intraspecific variation in diet can be an important component of a species niche breadth. We tested the hypothesis that sex differences in seasonal foraging behaviour and energy storage of sexually size dimorphic grey seals Halichoerus grypus (Fabrisius 1971) are reflected in differences in the diet and niche breadth. Diet composition was estimated for 496 adult (226 males, 270 females) and 91 juvenile (46 males/45 females; all 6 months old) grey seals sampled between 1993 and 2000 using quantitative fatty acid signature analysis. Niche breadth and overlap were estimated using the Shannon-Weaver diversity index (H') and the Morisita-Horn index (C(H)), respectively. 2. Sand lance Ammodytes dubius (Reinhardt 1837) and redfish Sebastes sp. (Cuvier 1829) accounted for a high proportion of the diet in both sexes and age groups. However, the diets of adult males were significantly more diverse across all seasons (H': males 0.36 +/- 0.007 vs. females 0.28 +/- 0.007) and less energy dense in spring (male 5.3 +/- 0.07 kJ g(-1) vs. females 5.6 +/- 0.09 kJ g(-1)) than those of adult females. 3. Season and sex explained most of the observed variation in adult diets, but there were significant sex-season interactions. These differences were most evident during the post-breeding (spring) foraging period when energy acquisition is important to female recovery of nutrient stores needed to support pregnancy. Females selected fewer and higher quality prey species in spring than males. 4. There were no sex differences in the diets of juvenile grey seals. Although many of the species overlapped with those eaten by adults, juvenile niche breadth (H': 0.41 +/- 0.014, n = 91) was significantly broader than that of adults (H': 0.30 +/- 0.011, n = 115). Juvenile diets were also of lower energy density (5.3 +/- 0.04 kJ g(-1)) than those of adults (5.6 +/- 0.09 kJ g(-1)), suggesting less selectivity in these young and relatively na?ve predators. 5. Sex-specific seasonal changes in diet correspond to seasonal changes in diving behaviour and rate of body energy accumulation of adult males and females. Sex-specific reproductive requirements appear to be a primary factor generating the intraspecific variation in the seasonal foraging ecology of this large marine carnivore. However, sex differences in the breadth and energy content of diets also suggest the influence of body-size dimorphism as a factor shaping the diet of this species.  相似文献   

12.
Observations were made on the feeding behavior of 34 lactating rhesus females (Macaca mulatta) at Tughlaqabad, India. Consistent interindividual differences in feeding times were found and two sources of this variation were identified. Time spent feeding was found to decline with female age; rhesus mothers 4–6 years old spent over 40% more time feeding than did females 11–15 years of age. When the animals were divided into high- and low-status groups, dominance was also found to relate to individual feeding times; high-status females spent more time feeding that did low-status females, but this difference was evident only when the effect of female age was held constant. The age effect is probably an expression of age-related variation in nutritional requirements due to growth in the youngest subject and, perhaps, a declining basal metabolic rate in the oldest. We speculate that the comparatively weak dominance effect is due less to the aggressive interruption of feeding bouts than it is to a presumed greater vigilance on the part of subordinant mothers in monitoring their infants' whereabouts.  相似文献   

13.
Individual-level diet variation was investigated in Gracilinanus microtarsus , an insectivorous marsupial whose diet is affected by sex and season in the highly seasonal Brazilian Cerrado. To measure individual-level diet variation, the diets of individual males and females were compared to that of their population in the warm-wet and cool-dry seasons using the proportional similarity index (PS i ). This index varies from 1 (complete overlap between the individual i  's and population's diets) toward 0 (decreasing overlap). Mean PS i values were computed as a measure of the degree of interindividual diet variation (the larger the mean PS i value, the smaller the variation among individuals' diets). Interindividual diet variation among females was similar between seasons, whereas among males it decreased from the warm-wet to the cool-dry season. Diet variation among males is probably reduced in the cool-dry season because of constraints on food consumption generated by interactions between endogenous (physiological needs associated with high rates of body mass growth) and exogenous (food limitation) factors.  相似文献   

14.
Farming is among the three most hazardous occupations in modern society and perhaps also held a similar position during the medieval period. The goal of this study was to determine if there is a significant difference in frequencies and patterns of longbone fracture trauma observed between rural and urban activity bases that distinguish farming as a particularly dangerous occupation during the medieval period. The longbones of 170 individuals excavated from Raunds, a rural medieval British site (10th–12th centuries AD) were examined for fractures and compared to data collected from four contemporary British medieval sites, one rural and three urban. The fracture frequency for the Raunds individuals (19.4%) was significantly different from the urban sites (4.7–5.5%). Female fractures were characterized by injury to the forearm, while the males were predisposed to diverse fracture locations. Clinical research provided a source of documented farm-related trauma from North America and Europe where the crops and animals raised, the manual chores performed, and the equipment used in traditional or small-scale farms have changed little in form or function since the medieval period. Nonmechanized causes of injury contribute to approximately 40% of all modern farm-related injuries and are attributed to falls from lofts and ladders, animal assaults and bites, and falls from moving vehicles. These hazardous situations were also present in the medieval period and may explain some of the fracture trauma from the rural sites. A high fracture frequency for both medieval males and females is significantly associated with farming subsistence when compared to craft-orientated urban dwellers. Am J Phys Anthropol 109:229–243, 1999. © 1999 Wiley-Liss, Inc.  相似文献   

15.
The objective of this study was to compare the immediate and long-term effects of type of infant diet (formula-fed vs. breast-fed) on the weight growth of baboons. Longitudinal (serial) weight data were collected from 44 savannah baboons (Papio cynocephalus anubis) for the total preadult period of growth from birth to approximately 8 years of age. Fifty percent of the sample (11 females and 11 males) were fed a standard infant formula by a nursery care technician for the first 18 weeks of postnatal life. The remaining 11 females and 11 males were breast-fed by their mothers for an equivalent period of time. After 18 weeks of age the animals were removed from their infant environments (either nursery or mother-reared) and assigned to one of four age-cohort social groups. Each age-cohort group was balanced for infant treatment and gender. The animals remained in these social groups for the duration of the project and were provided nutritionally identical postweaning diets. No significant weight differences were found between the two rearing conditions for either gender during the initial 15 weeks of growth. Following this period, however, females of breast-fed environments averaged greater weight at all ages than their bottle-fed peers. The intensity of the adolescent growth spurt was also slightly greater among the female breast-fed group. No postinfant average weight-per-age disparity was observed between the male treatment groups.  相似文献   

16.
The level of dietary energy intake influences metabolism, reproductive function, the development of age-related diseases, and even cognitive behavior. Because males and females typically play different roles in the acquisition and allocation of energy resources, we reasoned that dietary energy intake might differentially affect the brains of males and females at the molecular level. To test this hypothesis, we performed a gene array analysis of the hippocampus in male and female rats that had been maintained for 6 months on either ad libitum (control), 20% caloric restriction (CR), 40% CR, intermittent fasting (IF) or high fat/high glucose (HFG) diets. These diets resulted in expected changes in body weight, and circulating levels of glucose, insulin and leptin. However, the CR diets significantly increased the size of the hippocampus of females, but not males. Multiple genes were regulated coherently in response to energy restriction diets in females, but not in males. Functional physiological pathway analyses showed that the 20% CR diet down-regulated genes involved in glycolysis and mitochondrial ATP production in males, whereas these metabolic pathways were up-regulated in females. The 40% CR diet up-regulated genes involved in glycolysis, protein deacetylation, PGC-1alpha and mTor pathways in both sexes. IF down-regulated many genes in males including those involved in protein degradation and apoptosis, but up-regulated many genes in females including those involved in cellular energy metabolism, cell cycle regulation and protein deacetylation. Genes involved in energy metabolism, oxidative stress responses and cell death were affected by the HFG diet in both males and females. The gender-specific molecular genetic responses of hippocampal cells to variations in dietary energy intake identified in this study may mediate differential behavioral responses of males and females to differences in energy availability.  相似文献   

17.
What leads some people to perform better than others on certain cognitive tasks? One explanation involves individual differences in testosterone. Testosterone is associated with higher performance on spatial tests, and lower performance on verbal tests. However, a large literature suggests that testosterone only predicts behavior when status is in jeopardy. In the present study, we manipulated status before administering a spatial and verbal test. In a high-status position, high-testosterone individuals performed well on both tests, and blood pressure dropped. In a low-status position, high-testosterone individuals performed relatively poorly on both tests, and blood pressure did not change. These data suggest that differences in cognitive performance stem from an interaction between testosterone and the social situation.  相似文献   

18.
A common approach in the study of life-history trade-off evolution is to manipulate the nutrient content of diets during the life of an individual in order observe how the acquisition of resources influences the relationship between reproduction, lifespan and other life-history parameters such as dispersal. Here, we manipulate the quality of diet that replicate laboratory populations received as a thorough test of how diet quality influences the life-history trade-offs associated with reproductive investment in a nuptial feeding Australian ground cricket (Pteronemobius sp.). In this species, both males and females make significant contributions to the production of offspring, as males provide a nuptial gift by allowing females to chew on a modified tibial spur during copulation and feed directing on their haemolymph. Individuals also have two distinct wing morphs, a short-winged flightless morph and a long-winged morph that has the ability to disperse. By manipulating the quality of diet over seven generations, we found that the reproductive investment of males and females were affected differently by the diet quality treatment and wing morph of the individual. We discuss the broader implications of these findings including the differences in how males and females balance current and future reproductive effort in nuptial feeding insects, the changing nature of sexual selection when diets vary, and how the life-history trade-offs associated with the ability to disperse are expected to differ among populations.  相似文献   

19.
Sexual size dimorphism (SSD) is widespread among diverse animal taxa and has attracted the attention of evolutionary biologists for over a century. SSD is likely to be adaptive and the result of divergent selection on different size optima for males and females, given their different roles in reproduction. The developmental trajectory leading to SSD may help us to understand how selection acts on male and female size. Here, we describe the growth and development of two Australian praying mantids, Pseudomantis albofimbriata and Hierodula majuscula including the number of moults, time to adulthood, size at each moult, and the degree of SSD. While both species exhibit the common pattern of female-biased SSD, the number of moults required for individuals to reach adulthood differed between males and females and between species. Despite their larger adult size, P. albofimbriata females require fewer moults and less time than males to reach adulthood, but are significantly larger than males from the second instar onwards. In contrast, H. majuscula males reached adulthood in fewer moults, and less time than females, however males and females did not differ in size until females went through their final moult into adulthood. H. majuscula also required more time and more moults to reach adulthood than 17. albofimbriata. We discuss these different developmental pathways in light of the existing knowledge of reproductive biology for each species. We also suggest that these differences may relate to the different phenologies that occur in strongly seasonal temperate environments compared with those in the tropics. This study provides evidence that SSD can result from two different patterns of growth and development in closely related species.  相似文献   

20.
The diet and partitioning of food resources among mid-sized mammalian carnivores is poorly known, especially in the tropics. We evaluated the resource partitioning between Leopardus pardalis (ocelot), Cerdocyon thous (crab-eating fox), and Nasua nasua (brown-nosed coati) in the Pantanal of Brazil. Between December 2005 and February 2008, we collected data necessary to better understand interspecific, intraspecific, and seasonal variability in diet. Food habits were assessed by analysis of feces (n?=?293) collected from known individuals (n?=?128), and differences in dietary composition were evaluated through nonmetric dimensional scaling using the Jaccard similarity index. The main diet differences were observed between the specialist ocelot and the more generalist crab-eating fox and brown-nosed coati. Crab-eating foxes and brown-nosed coatis preyed on arthropods, fruits, and vertebrates whereas ocelots preyed almost entirely on vertebrates, mainly rodents and snakes. Ocelots’ consumption of snakes was the highest ever recorded, as was the extent of carnivory by brown-nosed coatis. For the crab-eating fox and the brown-nosed coati, there were large differences between the use of fruits and animal foods in the wet and dry season. Yet for both species there were no significant differences in the diets of males and females. Despite the conspicuous sexual dimorphism and spatial segregation that are typical of brown-nosed coatis, the results do not support the hypothesis that size dimorphism is primarily an adaptation to reduce intersexual competition for food. Rather, dimorphisms and patterns of space use may be more related to competition among males for access to females.  相似文献   

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