Freezer anthropology: new uses for old blood.
Archived blood fractions (plasma, settled red cells, white cells) have proved to be a rich and valuable source of DNA for human genetic studies. Large numbers of such samples were collected between 1960 and the present for protein and blood group studies, many of which are languishing in freezers or have already been discarded. More are discarded each year because the usefulness of these samples is not widely understood. Data from DNA derived from 10-35-year-old blood samples have been used to address the peopling of the New World and of the Pacific. Mitochondrial DNA haplotypes from studies using this source DNA support a single wave of migration into the New World (or a single source population for the New World), and that Mongolia was the likely source of the founding population. Data from Melanesia have shown that Polynesians are recent immigrants into the Pacific and did not arise from Melanesia. (+info)
Folkecology and commons management in the Maya Lowlands.
Three groups living off the same rainforest habitat manifest strikingly distinct behaviors, cognitions, and social relationships relative to the forest. Only the area's last native Maya reveal systematic awareness of ecological complexity involving animals, plants, and people and practices clearly favoring forest regeneration. Spanish-speaking immigrants prove closer to native Maya in thought, action, and social networking than do immigrant Maya. There is no overriding "local," "Indian," or "immigrant" relationship to the environment. Results indicate that exclusive concern with rational self-interest and institutional constraints do not sufficiently account for commons behavior and that cultural patterning of cognition and access to relevant information are significant predictors. Unlike traditional accounts of relations between culture, cognition, and behavior, the models offered are not synthetic interpretations of people's thoughts and behaviors but are emergent cultural patterns derived statistically from measurements of individual cognitions and behaviors. (+info)
The early Upper Paleolithic human skeleton from the Abrigo do Lagar Velho (Portugal) and modern human emergence in Iberia.
The discovery of an early Upper Paleolithic human burial at the Abrigo do Lagar Velho, Portugal, has provided evidence of early modern humans from southern Iberia. The remains, the largely complete skeleton of a approximately 4-year-old child buried with pierced shell and red ochre, is dated to ca. 24,500 years B.P. The cranium, mandible, dentition, and postcrania present a mosaic of European early modern human and Neandertal features. The temporal bone has an intermediate-sized juxtamastoid eminence. The mandibular mentum osseum and the dental size and proportions, supported by mandibular ramal features, radial tuberosity orientation, and diaphyseal curvature, as well as the pubic proportions align the skeleton with early modern humans. Body proportions, reflected in femorotibial lengths and diaphyseal robusticity plus tibial condylar displacement, as well as mandibular symphyseal retreat and thoracohumeral muscle insertions, align the skeleton with the Neandertals. This morphological mosaic indicates admixture between regional Neandertals and early modern humans dispersing into southern Iberia. It establishes the complexities of the Late Pleistocene emergence of modern humans and refutes strict replacement models of modern human origins. (+info)
Why hunter-gatherer populations do not show signs of pleistocene demographic expansions.
The mitochondrial DNA diversity of 62 human population samples was examined for potential signals of population expansions. Stepwise expansion times were estimated by taking into account heterogeneity of mutation rates among sites. Assuming an mtDNA divergence rate of 33% per million years, most populations show signals of Pleistocene expansions at around 70,000 years (70 KY) ago in Africa and Asia, 55 KY ago in America, and 40 KY ago in Europe and the Middle East, whereas the traces of the oldest expansions are found in East Africa (110 KY ago for the Turkana). The genetic diversity of two groups of populations (most Amerindian populations and present-day hunter-gatherers) cannot be explained by a simple stepwise expansion model. A multivariate analysis of the genetic distances among 61 populations reveals that populations that did not undergo demographic expansions show increased genetic distances from other populations, confirming that the demography of the populations strongly affects observed genetic affinities. The absence of traces of Pleistocene expansions in present-day hunter-gatherers seems best explained by the occurrence of recent bottlenecks in those populations, implying a difference between Pleistocene (approximately 1,800 KY to 10 KY ago) and Holocene (10 KY to present) hunter-gatherers demographies, a difference that occurred after, and probably in response to, the Neolithic expansions of the other populations. (+info)
A finding of oligocene primates on the European continent.
In this paper, we provide evidence that contrary to the current view, primates on the European continent did survive the dramatic extinction/origination event across the Eocene/Oligocene boundary 34 million years ago that severely affected the Eurasian mammal communities (the European "Grande Coupure" and the Asian "Mongolian Remodeling"). The survival of a mouse-sized omomyid for at least 2 million years, recorded in two localities of the Lower Stampian (Lower Oligocene) in a well dated stratigraphic series of fluviatile sediments in the north oriental sector of the Ebro Basin (Northeastern Spain), reflects the size-related survival pattern described recently for other coeval mammalian taxa. (+info)
Mid-Pleistocene Acheulean-like stone technology of the Bose basin, South China.
Stone artifacts from the Bose basin, South China, are associated with tektites dated to 803,000 +/- 3000 years ago and represent the oldest known large cutting tools (LCTs) in East Asia. Bose toolmaking is compatible with Mode 2 (Acheulean) technologies in Africa in its targeted manufacture and biased spatial distribution of LCTs, large-scale flaking, and high flake scar counts. Acheulean-like tools in the mid-Pleistocene of South China imply that Mode 2 technical advances were manifested in East Asia contemporaneously with handaxe technology in Africa and western Eurasia. Bose lithic technology is associated with a tektite airfall and forest burning. (+info)
Reflexivity--a strategy for a patient-centred approach in general practice.
Reflexivity as a strategy in general practice can be used to implement a patient-centred approach in the consultation. General practice has long represented a tradition attempting to integrate both illness and disease. For the GP, it is natural to focus on the patient's whole situation, and the GP's experience with patients is often based on a long-term relationship. Reflexivity implies having a self-conscious account of the production of knowledge as it is being produced. We believe that GPs can gain access to additional knowledge by consciously using reflexivity as a strategy in the consultation. In the present article, we discuss reflexivity in relation to the notions of empathy, personal experience and self-knowledge. By using reflexivity in order to rely on personal experience, the GP can gain access to patients' understanding of their health. Reflexivity can be a valuable concept for the GP in patient-centred medicine and can contribute to bridging the gap between the patient's perspective and the doctor's understanding of the patient's health. (+info)
Stable isotope evidence for increasing dietary breadth in the European mid-Upper Paleolithic.
New carbon and nitrogen stable isotope values for human remains dating to the mid-Upper Paleolithic in Europe indicate significant amounts of aquatic (fish, mollusks, and/or birds) foods in some of their diets. Most of this evidence points to exploitation of inland freshwater aquatic resources in particular. By contrast, European Neandertal collagen carbon and nitrogen stable isotope values do not indicate significant use of inland aquatic foods but instead show that they obtained the majority of their protein from terrestrial herbivores. In agreement with recent zooarcheological analyses, the isotope results indicate shifts toward a more broad-spectrum subsistence economy in inland Europe by the mid-Upper Paleolithic period, probably associated with significant population increases. (+info)