Human Colonization of Asia in the Late Pleistocene The History of an Invasive Species

Narratives of “Out of Africa 2”—the expansion of Homo sapiens across Asia—emphasize the pattern of human dispersal but not the underlying processes. In recent years, the main debates have been over the timing and frequency of dispersal. Here, I treat these issues as subordinate to biogeographic ones that affected the behavior of humans in Asia as an invasive species that colonized new environments and had negative impacts on indigenous hominins. I suggest that attention should focus on three issues: (i) geographic factors that molded human dispersal across Asia, (ii) behavioral changes that enabled humans to overcome previously insurmountable barriers, and (iii) demographic considerations of human dispersal and colonization of Asia, including interactions with indigenous competitors. Although a strong case can be made that humans dispersed across southern Asia before 60 ka, this should not detract from attention on the underlying processes of dispersal and colonization

The Red Sea, Coastal Landscapes, and Hominin Dispersals

This chapter provides a critical assessment of environment, landscape and resources in the Red Sea region over the past five million years in relation to archaeological evidence of hominin settlement, and of current hypotheses about the role of the region as a pathway or obstacle to population dispersals between Africa and Asia and the possible significance of coastal colonization. The discussion assesses the impact of factors such as topography and the distribution of resources on land and on the seacoast, taking account of geographical variation and changes in geology, sea levels and palaeoclimate. The merits of northern and southern routes of movement at either end of the Red Sea are compared. All the evidence indicates that there has been no land connection at the southern end since the beginning of the Pliocene period, but that short sea crossings would have been possible at lowest sea-level stands with little or no technical aids. More important than the possibilities of crossing the southern channel is the nature of the resources available in the adjacent coastal zones. There were many climatic episodes wetter than today, and during these periods water draining from the Arabian escarpment provided productive conditions for large mammals and human populations in coastal regions and eastwards into the desert. During drier episodes the coastal region would have provided important refugia both in upland areas and on the emerged shelves exposed by lowered sea level, especially in the southern sector and on both sides of the Red Sea. Marine resources may have offered an added advantage in coastal areas, but evidence for their exploitation is very limited, and their role has been over-exaggerated in hypotheses of coastal colonization

The Effects of Cognitive Stress on Asthma Exacerbations among University Students

Introduction: Many asthmatics complain of worsening respiratory symptoms during periods of stress.This study evaluated the relationship among asthma symptoms, lung physiology, inflammatory parametersand perceived cognitive stress and quality of life in healthy adult students. This relationship was assessedat two time points: a time of normal activity and at a time of cognitive stress during academic examinations. Methods: Subjects attended the University of Alberta Hospital for a screening visit, which included aclinical exam, spirometry, methacholine challenge, allergen skin tests to assess atopy status and MiniInternational Neuropsychiatric Interview (MINI). Eligible subjects returned for a low stress visit (LSV) atleast 14 days prior to an exam and a high stress visit (HSV) within 24 hours of an exam. Spirometry, andmethacholine challenge were performed during both LSV and HSV along with the collection of urine (testedfor cortisol), and the administration of 4 questionnaires to assess perceived stress and quality of life. Results: Subjects showed no significant change in psychosocial or quality of life questionnaires betweenLSV and HSV. No significant change was noted in lung function or urine cortisol. There was an unexpectedhigh rate of pre-existing psychiatric comorbidities in this population (based on the MINI screen failure rate).Conclusion: We did not find a significant change in quality of life, psychosocial wellbeing or pulmonaryfunction or inflammation, measured by urine cortisol, during a high stress period. The high rate ofcomorbidities would be important to consider as part of evaluation used in clinical asthma studies in the future

Hominin occupation of the Chinese Loess Plateau since about 2.1 million years ago

Considerable attention has been paid to dating the earliest appearance of hominins outside Africa. The earliest skeletal and artefactual evidence for the genus Homo in Asia currently comes from Dmanisi, Georgia, and is dated to approximately 1.77-1.85 million years ago (Ma)(1). Two incisors that may belong to Homo erectus come from Yuanmou, south China, and are dated to 1.7 Ma(2); the next-oldest evidence is an H. erectus cranium from Lantian (Gongwangling)-which has recently been dated to 1.63 Ma(3) and the earliest hominin fossils from the Sangiran dome in Java, which are dated to about 1.5-1.6 Ma(4). Artefacts from Majuangou III5 and Shangshazui(6) in the Nihewan basin, north China, have also been dated to 1.6-1.7 Ma. Here we report an Early Pleistocene and largely continuous artefact sequence from Shangchen, which is a newly discovered Palaeolithic locality of the southern Chinese Loess Plateau, near Gongwangling in Lantian county. The site contains 17 artefact layers that extend from palaeosol S15-dated to approximately 1.26 Ma-to loess L28, which we date to about 2.12 Ma. This discovery implies that hominins left Africa earlier than indicated by the evidence from Dmanisi

A demographic history of Late Pleistocene China

This paper proposes a demographic history of China in the last glacial cycle. This history is complex because China lies in both the Palearctic and Oriental biographic realms, and experienced several immigration events before H. sapiens. Immigration by our species into the Oriental Realm of south China from southeast Asia probably began as early as 80,000 years ago. North China has a different history: here, humans immigrated from Mongolia and southern Siberia ca. 45,000 years ago as part of a cold-adapted Palearctic fauna. These populations were largely independent of one another, and each needs to be seen as part of their respective biogeographic realms. The subsequent demographic history of China is one of mixing and inter-breeding of populations from both north and south China. In the LGM, north China (and Mongolia) were largely depopulated, and subsequent recolonization of north China occurred from both the north and the south. Explanations of the demographic history of China have to include developments beyond its borders, immigration, assimilation of new populations, and continuity of local groups

Lithic artifact assemblage transport and micro-wear modification in a fluvial setting: a radio frequency identification tag experiment

River processes are widely assumed to have impacted the integrity of lithic assemblages when artifacts are found in fluvial sediments, but the specifics of these influences remain largely unknown. We conducted a real-world experiment to determine how the initial stages of fluvial entrainment affected lithic artifact assemblages. We inserted replica artifacts with Radio Frequency Identification (RFID) tags into a gravel-bedded river in Wales (UK) for seven months and related their transport distances to their morphology and the recorded streamflow. Additionally, nine artifacts were recovered at the end of the experiment and analyzed for micro-wear traces. In sum, our results show that in a gravel bedded river with a mean discharge of 5.1 m3s-1, artifact length and width were the main variables influencing artifact transport distances. The experiment also resulted in characteristic micro-wear traces developing on the artifacts over distances of 485 m or less. These results emphasize the multifaceted nature of alluvial site formation processes in a repeatable experiment and highlight new ways to identify the transport of replica Paleolithic material

Craniometric Data Supports Demic Diffusion Model for the Spread of Agriculture into Europe

BACKGROUND:The spread of agriculture into Europe and the ancestry of the first European farmers have been subjects of debate and controversy among geneticists, archaeologists, linguists and anthropologists. Debates have centred on the extent to which the transition was associated with the active migration of people as opposed to the diffusion of cultural practices. Recent studies have shown that patterns of human cranial shape variation can be employed as a reliable proxy for the neutral genetic relationships of human populations. METHODOLOGY/PRINCIPAL FINDINGS:Here, we employ measurements of Mesolithic (hunter-gatherers) and Neolithic (farmers) crania from Southwest Asia and Europe to test several alternative population dispersal and hunter-farmer gene-flow models. We base our alternative hypothetical models on a null evolutionary model of isolation-by-geographic and temporal distance. Partial Mantel tests were used to assess the congruence between craniometric distance and each of the geographic model matrices, while controlling for temporal distance. Our results demonstrate that the craniometric data fit a model of continuous dispersal of people (and their genes) from Southwest Asia to Europe significantly better than a null model of cultural diffusion. CONCLUSIONS/SIGNIFICANCE:Therefore, this study does not support the assertion that farming in Europe solely involved the adoption of technologies and ideas from Southwest Asia by indigenous Mesolithic hunter-gatherers. Moreover, the results highlight the utility of craniometric data for assessing patterns of past population dispersal and gene flow

Ancient DNA from Hunter-Gatherer and Farmer Groups from Northern Spain Supports a Random Dispersion Model for the Neolithic Expansion into Europe

Background/Principal Findings: The phenomenon of Neolithisation refers to the transition of prehistoric populations from a hunter-gatherer to an agro-pastoralist lifestyle. Traditionally, the spread of an agro-pastoralist economy into Europe has been framed within a dichotomy based either on an acculturation phenomenon or on a demic diffusion. However, the nature and speed of this transition is a matter of continuing scientific debate in archaeology, anthropology, and human population genetics. In the present study, we have analyzed the mitochondrial DNA diversity in hunter-gatherers and first farmers from Northern Spain, in relation to the debate surrounding the phenomenon of Neolithisation in Europe. Methodology/Significance: Analysis of mitochondrial DNA was carried out on 54 individuals from Upper Paleolithic and Early Neolithic, which were recovered from nine archaeological sites from Northern Spain (Basque Country, Navarre and Cantabria). In addition, to take all necessary precautions to avoid contamination, different authentication criteria were applied in this study, including: DNA quantification, cloning, duplication (51 % of the samples) and replication of the results (43 % of the samples) by two independent laboratories. Statistical and multivariate analyses of the mitochondrial variability suggest that the genetic influence of Neolithisation did not spread uniformly throughout Europe, producing heterogeneous genetic consequences in different geographical regions, rejecting the traditional models that explain the Neolithisation in Europe

Moult cycle specific differential gene expression profiling of the crab Portunus pelagicus

Background: Crustacean moulting is a complex process involving many regulatory pathways. A holistic approach to examine differential gene expression profiles of transcripts relevant to the moulting process, across all moult cycle stages, was used in this study. Custom cDNA microarrays were constructed for Portunus pelagicus. The printed arrays contained 5000 transcripts derived from both the whole organism, and from individual organs such as the brain, eyestalk, mandibular organ and Y-organ from all moult cycle stages.Results: A total of 556 clones were sequenced from the cDNA libraries used to construct the arrays. These cDNAs represented 175 singletons and 62 contigs, resulting in 237 unique putative genes. The gene sequences were classified into the following biological functions: cuticular proteins associated with arthropod exoskeletons, farnesoic acid O-methyltransferase (FaMeT), proteins belonging to the hemocyanin gene family, lectins, proteins relevant to lipid metabolism, mitochondrial proteins, muscle related proteins, phenoloxidase activators and ribosomal proteins. Moult cycle-related differential expression patterns were observed for many transcripts. Of particular interest were those relating to the formation and hardening of the exoskeleton, and genes associated with cell respiration and energy metabolism.Conclusions: The expression data presented here provide a chronological depiction of the molecular events associated with the biological changes that occur during the crustacean moult cycle. Tracing the temporal expression patterns of a large variety of transcripts involved in the moult cycle of P. pelagicus can provide a greater understanding of gene function, interaction, and regulation of both known and new genes with respect to the moulting process