« Pister » les images préhistoriques : un exemple saharien

The chronological assignation of Laghchiwat's engravings, a new major rock art site in the south of Morocco, has not been established yet. In that purpose, we are wondering in an unprecedented way about the entanglement in local and prehistoric graphic productions in general. The capacity of reusing a same line by incorporating it into different forms constitutes a codified virtuosity and a complex intellectual exercise. We try to connect this approach with another kind of concrete clue decoding, the tracking, and with the interpretative ability which is required among human societies of hunter-gatherers. By comparing final Paleolithic images (rather predatory societies), which often use the plural reading of the line, to those of the Neolithic (rather productives societies), favorising its monosemia, we seek to highlight the cognitive skills which preside over this or that choice and thus, by extension, perhaps to catch a sight of the oldest iconographical phase of both site and region.     

Neandertal versus Modern Human Dietary Responses to Climatic Fluctuations

The Neandertal lineage developed successfully throughout western Eurasia and effectively survived the harsh and severely changing environments of the alternating glacial/interglacial cycles from the middle of the Pleistocene until Marine Isotope Stage 3. Yet, towards the end of this stage, at the time of deteriorating climatic conditions that eventually led to the Last Glacial Maximum, and soon after modern humans entered western Eurasia, the Neandertals disappeared. Western Eurasia was by then exclusively occupied by modern humans. We use occlusal molar microwear texture analysis to examine aspects of diet in western Eurasian Paleolithic hominins in relation to fluctuations in food supplies that resulted from the oscillating climatic conditions of the Pleistocene. There is demonstrable evidence for differences in behavior that distinguish Upper Paleolithic humans from members of the Neandertal lineage. Specifically, whereas the Neandertals altered their diets in response to changing paleoecological conditions, the diets of Upper Paleolithic humans seem to have been less affected by slight changes in vegetation/climatic conditions but were linked to changes in their technological complexes. The results of this study also indicate differences in resource exploitation strategies between these two hominin groups. We argue that these differences in subsistence strategies, if they had already been established at the time of the first contact between these two hominin taxa, may have given modern humans an advantage over the Neandertals, and may have contributed to the persistence of our species despite habitat-related changes in food availabilities associated with climate fluctuations.     

Mortality rates among wild chimpanzees

In order to compare evolved human and chimpanzees' life histories we present a synthetic life table for free-living chimpanzees, derived from data collected in five study populations (Gombe, Ta?, Kibale, Mahale, Bossou). The combined data from all populations represent 3711 chimpanzee years at risk and 278 deaths. Males show higher mortality than females and data suggest some inter-site variation in mortality. Despite this variation, however, wild chimpanzees generally have a life expectancy at birth of less than 15 years and mean adult lifespan (after sexual maturity) is only about 15 years. This is considerably lower survival than that reported for chimpanzees in zoos or captive breeding colonies, or that measured among modern human hunter-gatherers. The low mortality rate of human foragers relative to chimpanzees in the early adult years may partially explain why humans have evolved to senesce later than chimpanzees, and have a longer juvenile period.     

A multistage theory of age-specific acceleration in human mortality

Background  

Humans die at an increasing rate until late in life, when mortality rates level off. The causes of the late-life mortality plateau have been debated extensively over the past few years. Here, I examine mortality patterns separately for each of the leading causes of death. The different causes of death show distinct mortality patterns, providing some clues about the varying acceleration of mortality at different ages.     

Demographic and health patterns in a rural community from the Basque area in Spain (1800-1990)

In this work, the evolution of demographic and health patterns in a Basque rural population from Spain is analysed, as they relate to progress in demographic and epidemiological transition. For this purpose, parochial record data on 13,298 births and 9,215 deaths, registered during the 19th and 20th centuries (1800-1990), were examined. The study area is a rural community called Lanciego, which is located at the southern end of the Rioja Alavesa area (Alava Province, Basque Country). In Lanciego, demographic transition began in the final decade of the 19th century, when a definite, irreversible trend began towards a reduction in mortality. The decrease in the birth rate came later than that in the death rate, and did not start until the 1930s. The post-transitional stage seemed to be reached in the 1970s, when the birth and death rates showed values below 20 per 1,000. Other characteristics observed for the post-transitional stage in Lanciego are: (i) very low rates of infant mortality achieved at the expense of effective control of exogenous mortality; (ii) the mortality curve by ages changes from a U-shape (typical of populations with a high infant mortality rate and low life expectancy at birth) to a J-shape more characteristic of modern societies where longevity and life expectancy are considerably higher; (iii) a certain level of over-mortality among women in the senior age group (>65); and (iv) a significant proportion of mortality in recent times (1970-90) resulting from cardiovascular diseases and malignant neoplasms (post-transition causes). This last point is in contrast with observations from the first four decades of the 20th century, when infectious diseases and respiratory ailments were determining factors in mortality among this population. The data provided by the study of the variation over time in demographic and health patterns indicate that reducing the risk of mortality is one of the most important preconditions for fertility decline.     

Trade-Offs between female food acquisition and child care among hiwi and ache foragers

Even though female food acquisition is an area of considerable interest in hunter-gatherer research, the ecological determinants of women’s economic decisions in these populations are still poorly understood. The literature on female foraging behavior indicates that there is considerable variation within and across foraging societies in the amount of time that women spend foraging and in the amount and types of food that they acquire. It is possible that this heterogeneity reflects variation in the trade-offs between time spent in food acquisition and child care activities that women face in different groups of hunter-gatherers. In this paper we discuss the fitness trade-offs between food acquisition and child care that Hiwi and Ache women foragers might face. Multiple regression analyses show that in both populations the daily food acquisition of a woman’s spouse is negatively related to female foraging effort. In addition, nursing mothers spend less time foraging and acquire less food than do nonnursing women. As the number of dependents that a woman has increases, however, women also increase foraging time and the amount of food they acquire. Some interesting exceptions to these general trends are as follows: (a) differences in foraging effort between nursing and nonnursing women are less pronounced when fruits and roots are in season than in other seasons of the year; (b) foraging return rates decrease for Ache women as their numbers of dependents increase; and (c) among Ache women, the positive effect of number of dependents on foraging behavior is less pronounced when fruits are in season than at other times of the year. Lastly, in the Hiwi sample we found that postreproductive women work considerably harder than women of reproductive age in the root season but not in other seasons of the year. We discuss how ecological variation in constraints, the number of health insults to children that Hiwi and Ache mothers can avoid, and the fitness benefits they can gain from spending time in food acquisition and child care might account for differences and similarities in the foraging behaviors of subgroups of Hiwi and Ache mothers across different seasons of the year. Valid tests of the explanations we propose will require considerable effort to measure the relationship between maternal food acquisition, child care, and adverse health outcomes in offspring. This paper is dedicated to Nutsiya, the hardest-working grandmother we ever observed Kristen Hawkes contributed useful information on female foraging among the Hadza. The research was funded by the National Science Foundation (BNS-8613215, BNS-538228, BNS-8309834, BNS-8121209) and the L. S. B. Leakey Foundation. The senior author was supported by fellowships from the Fundacion Gran Mariscal de Ayacucho of Venezuela and the National Institute of Health (Grant No. 1 RO1 HD16221-01A2). A. Magdalena Hurtado, Kim Hill, and Hillard Kaplan collaborate in research on the evolutionary ecology of the division of labor by sex. Ines Hurtado is Senior Research Scientist at the Instituto Venezolano de Investigaciones Científicas, Venezuela. She studies the immunology of parasite load and atopic illness in Hiwi foragers.     

Mormon mortality rates in Canada

Abstract

In the United States, Mormons have been shown to have lower incidence and mortality rates of cancer and other diseases than the general population, a fact which has been attributed to the life style prescribed by the Mormon Church, including abstinence from tobacco, alcohol, coffee, and tea. This study examines Mormon cause‐specific mortality rates in Alberta, Canada, compared to rates for the general population of Alberta and of all Canada. Mormon death rates for most causes were lower than those for Alberta, which are themselves lower than Canadian rates. Mormon death rates for males were higher than for females for most causes, but male and female death rates were more similar among Mormons than in the general population. Causes of death for which Mormons have an average or higher than average risk are either less frequent causes or are less clearly related to dietary habits. Mormons have disproportionately low death rates for many causes which are not clearly related to the use of tobacco, alcohol, coffee, or tea. Further research is needed on the specific effects of different life‐style components and on the possible biological selectivity of the group.     

Why do women live longer than men?

In the contemporary United States, males have 60 percent higher mortality than females. In Part I, published in the previous issue, we showed that 40 percent of this sex differential in mortality is due to a twofold elevation of arteriosclerotic heart disease among men. Major causes of higher rates of arteriosclerotic heart disease in men include greater cigarette smoking among men; probably a greater prevalence of the competitive, aggressive Coronary Prone Behavior Pattern among men; and possibly a protective role of female hormones. In addition, men have higher death rates for lung cancer and emphysema, primarily because more men smoke cigarettes. In Part II we analyze the other major causes of men's higher death rates: accidents, suicide, and cirrhosis of the liver. Each of these is related to behaviors which are encouraged or accepted more in men than in women in our society--for example, using guns, being adventurous and acting unafraid, working at hazardous jobs and drinking alcohol. We conclude with suggestions for reducing male mortality; for example, by changing the social conditions which foster in men the behaviors that elevate their mortality.     

Evolutionary aspects of omega-3 fatty acids in the food supply

Information from archaeological findings and studies from modern day hunter-gatherers suggest that the Paleolithic diet is the diet we evolved on and for which our genetic profile was programmed. The Paleolithic diet is characterized by lower fat and lower saturated fat intake than Western diets; a balanced intake of omega-6 and omega-3 essential fatty acids; small amounts of trans fatty acids, contributing less than 2% of dietary energy; more green leafy vegetables and fruits providing higher levels of vitamin E and vitamin C and other antioxidants than today's diet and higher amounts of calcium and potassium but lower sodium intake. Studies on the traditional Greek diet (diet of Crete) indicate an omega-6/omega-3 ratio of about 1/1. The importance of a balanced ratio of omega-6:omega-3, a lower saturated fatty acid and lower total fat intake (30-33%), along with higher intakes of fruits and vegetables leading to increases in vitamin E and C, was tested in the Lyon Heart study. The Lyon study, based on a modified diet of Crete, confirmed the importance of omega-3 fatty acids from marine and terrestrial sources, and vitamin E and vitamin C, in the secondary prevention of coronary heart disease, and cancer mortality.     

Dental remains from the Grotte du Renne at Arcy-sur-Cure (Yonne)

Human remains associated with the earliest Upper Paleolithic industries are sparse. What is preserved is often fragmentary, making it difficult to accurately assign them to a particular species. For some time it has been generally accepted that Neandertals were responsible for the Chatelperronian and anatomically modern humans for the early Aurignacian industries. However, the recent re-dating of several of the more-complete modern human fossils associated with the early Aurignacian (e.g., Vogelherd) has led some to question the identity of the makers and the context of these early Upper Paleolithic industries. The Grotte du Renne at Arcy-sur-Cure, France has yielded many hominin remains, from Mousterian, Chatelperronian, Aurignacian, and Gravettian layers. Previously, a child's temporal bone from the Chatelperronian Layer Xb was recognized as belonging to a Neandertal; however, most of the teeth from Chatelperronian layers VIII-X remain unpublished. We describe the dental remains from the Chatelperronian layers, place them in a comparative (Mousterian Neandertal and Upper Paleolithic modern human) context, and evaluate their taxonomic status. The teeth (n = 29) represent a minimum of six individuals aged from birth to adult. The permanent dental sample (n = 15) from the Chatelperronian layers of Arcy-sur-Cure exhibits traits (e.g., lower molar mid-trigonid crest) that occur more frequently in Neandertals than in Upper Paleolithic modern humans. Furthermore, several teeth show trait combinations, including Cusp 6/mid-trigonid crest/anterior fovea in the lower second molar, that are rare or absent in Upper Paleolithic modern humans. The deciduous teeth (n = 14) significantly increase the sample of known deciduous hominin teeth and are more similar to Mousterian Neandertals from Europe and Asia than to Upper Paleolithic modern humans. Thus, the preponderance of dental evidence from the Grotte du Renne strongly supports that Neandertals were responsible for the Chatelperronian industry at Arcy-sur-Cure.     

Human Identity and the Evolution of Societies

Human societies are examined as distinct and coherent groups. This trait is most parsimoniously considered a deeply rooted part of our ancestry rather than a recent cultural invention. Our species is the only vertebrate with society memberships of significantly more than 200. We accomplish this by using society-specific labels to identify members, in what I call an anonymous society. I propose that the human brain has evolved to permit not only the close relationships described by the social brain hypothesis, but also, at little mental cost, the anonymous societies within which such alliances are built. The human compulsion to discover or invent labels to “mark” group memberships may originally have been expressed in hominins as vocally learned greetings only slightly different in function from chimpanzee pant hoots (now known to be society-specific). The weight of evidence suggests that at some point, conceivably early in the hominin line, the distinct groups composed of several bands that were typical of our ancestors came to be distinguished by their members on the basis of multiple labels that were socially acquired in this way, the earliest of which would leave no trace in the archaeological record. Often overlooked as research subjects, these sizable fission-fusion communities, in recent egalitarian hunter-gatherers sometimes 2,000 strong, should consistently be accorded the status of societies, in the same sense that this word is used to describe tribes, chiefdoms, and other cultures arising later in our history. The capacity of hunter-gatherer societies to grow sufficiently populous that not all members necessarily recognize one another would make the transition to larger agricultural societies straightforward. Humans differ from chimpanzees in that societal labels are essential to the maintenance of societies and the processes giving birth to new ones. I propose that anonymous societies of all kinds can expand only so far as their labels can remain sufficiently stable.     

中国旧石器原料开发策略的研究进展

石料开发与获取是石器生产操作链的重要环节,也是史前人地关系研究的重要内容,能够反映史前人类的资源开发策略、环境认知与适应能力、移动模式和交流贸易网络等。相比于旧大陆西侧,东亚地区的燧石和黑曜岩等优质石料产地相对稀缺,中国许多旧石器考古遗址的石器原料主要来自遗址周边质量欠佳的脉石英、石英岩和一般燧石等,而相关的旧石器时代石料开发策略系统研究也相对较少。本文对中国目前已开展的旧石器时代石料开发策略研究进行系统梳理分析和总结发现,从旧石器时代早期到晚期末段,中国境内史前人类的石料开发策略存在明显的时空变化,主要体现在石料类型组成、产地选取和开发方式三个方面,可能主要受到史前人类流动性变化、石器技术演变和环境变化等因素的共同影响。综合而言,开展旧石器时代遗址的石料开发策略研究,对于理解中国境内史前人类的行为模式和交流迁徙等有重要意义。     

Stone tool analysis and human origins research: some advice from Uncle Screwtape

The production of purposefully fractured stone tools with functional, sharp cutting edges is a uniquely derived hominin adaptation. In the long history of life on earth, only hominins have adopted this remarkably expedient and broadly effective technological strategy. In the paleontological record, flaked stone tools are irrefutable proof that hominins were present at a particular place and time. Flaked stone tools are found in contexts ranging from the Arctic to equatorial rainforests and on every continent except Antarctica. Paleolithic stone tools show complex patterns of variability, suggesting that they have been subject to the variable selective pressures that have shaped so many other aspects of hominin behavior and morphology. There is every reason to expect that insights gained from studying stone tools should provide vital and important information about the course of human evolution. And yet, one senses that archeological analyses of Paleolithic stone tools are not making as much of a contribution as they could to the major issues in human origins research.     

Causes of infant mortality in the Middle Ages revealed by chemical and palaeopathological analyses of skeletal remains

In most prehistoric and historic populations, mortality of small infants is very high. Causes of death are mainly discussed in analogy to the situation in modern preindustrial societies. The children are at high risk to fall ill or even die especially in times of weaning. Trace element analysis of the skeletal remains of small infants excavated in Schleswig (northern Germany, 11th/12th century AD) led to the estimation of weaning age as well as to the reconstruction of a stepwise substitution of mothers' milk by other food items. Subsequent palaeopathological analysis confirmed high mortality in this age-group. Thus, causes of death of small infants in a medieval town can be outlined.     

Paleolithic hominin remains from Eshkaft-e Gavi (southern Zagros Mountains, Iran): description, affinities, and evidence for butchery

Eshkaft-e Gavi is a cave located in the southern Zagros Mountains of Iran and is one of the few archaeological sites in the region to preserve both Middle Paleolithic and Upper Paleolithic occupations. Excavation of the site in the 1970s yielded an assemblage of lithic and faunal remains, including ten hominin specimens: a mandibular molar, four cranial fragments, a clavicular diaphysis, the proximal half of a metacarpal, a fragment of os coxa, the proximal diaphysis of a juvenile femur, and a patella. The bones derive from a minimum of four individuals, including two juveniles. Although many of these remains could be Epi-Paleolithic in age, one of the juvenile specimens—the mandibular molar—occurs at the base of the cave's Upper Paleolithic sequence. The remains are very fragmentary, but those that preserve diagnostic morphology indicate that they represent modern humans. The molar is taxonomically diagnostic, thus confirming the association of the Aurignacian-like Baradostian Industry with modern humans. Four of the specimens—a piece of frontal bone, the clavicle, the juvenile femur, and the patella—display clear evidence for intentional butchery in the form of stone-tool cutmarks. These cutmarked specimens, along with a fragment of parietal bone, are also burned. Although this evidence is consistent with cannibalism, the small sample makes it difficult to say whether or not the individuals represented by the hominin remains were butchered and cooked for consumption. Nevertheless, the cutmarked Eshkaft-e Gavi specimens add to a growing sample of hominin remains extending back into the Plio-Pleistocene that display evidence of intentional defleshing.     

Dental indicators of health and stress in early Egyptian and Nubian agriculturalists: a difficult transition and gradual recovery

Although agriculture is now the globally predominant mode of food production, studies of the skeletal remains of early agriculturalists have indicated high levels of physiological stress and poor health relative to hunter-gatherers in similar environments. Previous studies identifying this trend in different regions prompt further research of the causes and effects of subsistence transitions in human societies. Here, 242 dentitions from five ancient Egyptian and Nubian populations are examined: 38 individuals from Jebel Sahaba (Upper Paleolithic), 56 from Badari (Predynastic), 54 from Naqada (Predynastic), 47 from Tarkhan (Dynastic), and 47 from Kerma (Dynastic). These populations span the early period of agricultural intensification along the Nile valley. Skeletal remains were scored for the presence of linear enamel hypoplasia (LEH) of the dentition, an established indicator of physiological stress and growth interruption. The prevalence of LEH was highest in the "proto-agricultural" (pastoralist) Badari population, with a gradual decline throughout the late Predynastic and early Dynastic periods of state formation. This suggests that the period surrounding the emergence of early agriculture in the Nile valley was associated with high stress and poor health, but that the health of agriculturalists improved substantially with the increasing urbanization and trade that accompanied the formation of the Egyptian state. This evidence for poor health among proto- and early agriculturalists in the Nile valley supports theories that agricultural intensification occurred as a response to ecological or demographic pressure rather than simply as an innovation over an existing stable subsistence strategy.     

Injury mortality in New Mexico's American Indians,Hispanics, and non-Hispanic whites, 1958 to 1982.

New Mexico has extraordinarily high injury mortality rates. To better characterize the injury problem in New Mexico, we calculated proportionate injury mortality and age-adjusted and age-specific injury mortality rates for the state''s 3 major ethnic groups--American Indians, Hispanics, and non-Hispanic whites. According to death certificate data collected from 1958 to 1982 and US population census figures, age-adjusted mortality rates for total external causes varied widely between the sexes and among the ethnic groups. Males in each ethnic group consistently had higher average annual age-adjusted external mortality rates than females. Injury mortality rates for American Indians of both sexes were 2 to 3 times higher than those for the other New Mexico ethnic groups. Motor vehicle crashes were the leading cause of death from injury for all 3 groups. Homicide accounted for twice the proportion of injury death in Hispanic compared with non-Hispanic white males (12.5% and 6.1%, respectively), while the proportion of males dying of suicide was highest in non-Hispanic whites. Deaths from excessive cold and exposure were leading causes of injury mortality for American Indians, but these causes were not among the leading causes of injury mortality for Hispanics or non-Hispanic whites. We conclude that the minority populations in New Mexico are at high risk for injury-related death and that the major causes of injury mortality vary substantially in the state''s predominant ethnic populations.     

Hazard rates and causes of death in a captive group of crab-eating monkeys (Macaca fascicularis)

In an attempt to examine possible associations between stages of agespecific mortality and various causes of death, vital records of 159 male and 192 female crab-eating monkeys (Macaca fascicularis), housed as a single group, were analyzed. Survival and hazard rates associated with each of five distinct categories of causes of death were estimated for males and females, using the nonparametric kernel method. The obtained overall survival and hazard functions were similar to those reported previously for rhesus monkeys. Among two stages identified in age-specific mortality, the first stage, characterized by rapidly decreasing hazard rates up to about 1.5–2 years of age, was discriminated by the occurrence of deaths due to unfitness for postnatal life. The second stage lasted up to the age of 10–15 years and was largely characterized by a high incidence of violent deaths. The respective hazard rates in males and females attained peaks during the early reproductive period of life and markedly decreased thereafter. This pattern was interpreted to indicate that second stage mortality is unlikely related to senescence, but rather, seems to depend on extrinsic environmental factors. Thus, when considering overall hazard rates in Macaca fascicularis, the onset of senescence, as a result of the specific aspects of simian reproduction, may be hidden from view, and mortality due to aging may only be appreciable after 10 to 15 years of age. © 1993 Wiley-Liss, Inc.     

Social class differences in years of potential life lost: size,trends, and principal causes.

British social class differences in mortality are examined in terms of years of potential life lost, a measure that gives more weight to deaths that take place at younger ages. It shows wider class differences during the years of working life than those found when mortality is expressed in terms of standardised mortality ratios. Examination of the change in class differences between 1971 and 1981 for all causes of death combined and for the three categories of death which during these ages make a major contribution to total years of potential life lost shows complex changes. Inequalities in years of potential life lost have increased between 1971 and 1981, during which all the principal causes of death have shown stationary or rising rates among the manual classes. The use of years of potential life lost as a measure of population health trends focuses attention on the major contribution of violent death, which occurs mainly in younger men, to widening class differences in mortality.