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Complex History (complex + history)
Selected AbstractsOrganizing Our Thoughts: "Global Systems" and the Challenge of Writing a More Complex HistoryTHE JOURNAL OF THE HISTORICAL SOCIETY, Issue 3 2010David Hancock First page of article [source] When simplicity is not parsimonious: a priori and a posteriori methods in historical biogeographyJOURNAL OF BIOGEOGRAPHY, Issue 1 2001Marco G. P. Van Veller Despite using the same null hypothesis, a priori and a posteriori approaches in historical biogeography differ fundamentally. Methods such as Component Analysis (CA) and Reconciled Tree Analysis (RTA) may eliminate or modify input data in order to maximize fit to the null hypothesis, by invoking assumptions 1 and 2. Methods such as Brooks Parsimony Analysis (BPA) modify the null hypothesis, if necessary, to maintain the integrity of the input data, as required by assumption 0. Two exemplars illustrate critical empirical differences between CA/RTA and BPA: (1) CA rather than BPA may select the incorrect general area cladogram for a set of data (2) BPA, not RTA, provides the most parsimonious interpretation of all available data and (3) secondary BPA, proposed in 1990, applied to data sets for which dispersal producing areas with reticulate histories is most parsimonious, provides biologically realistic interpretations of area cladograms. These observations lead to the conclusion that BPA and CA/RTA are designed to implement different research programmes based on different conceptual frameworks. BPA is designed to assess the biogeographic context of speciation events, whereas CA/RTA are designed to find the best fitting pattern of relationships among areas based on the taxa that inhabit them. Unique distributional elements and reticulate (hybrid) histories of areas are essential for explaining complex histories of speciation. The conceptual framework for BPA, thus, assumes biogeographical complexity, relying on parsimony as an explanatory tool to summarize complex results, whereas CA/RTA assumes biogeographical simplicity, assuming conceptual parsimony a priori. [source] Front and Back Covers, Volume 25, Number 2.ANTHROPOLOGY TODAY, Issue 2 2009April 200 Front cover caption, volume 25 issue 2 Front cover Ethnicity, Race and the Limits of Human Identity The front and back covers show artist Sean Weisgerber's interpretation of the theme of this issue, the problem of classifying human identity in a world of fusion and change. Articles address biometric security, the use of the concept of ,tribe' in US army counter-insurgency programmes, and human identity as constituted in and through debate among Afghani refugees recently returned from northern Pakistan to Afghanistan. The difficulty of fitting human diversity into strictly defined categories is most acutely evident in questions asked on census forms. In this issue, Peter Aspinall considers the broad range of terms proposed and debated for the ,mixed race' population. Many have complex histories and have been used to subsume individuals of varied and sometimes disparate ethnic and racial origins. Dissatisfaction with the widely used term ,mixed race', contested by anthropologists and sociologists among others on the grounds that it references the now discredited concept of ,race', has led to the search for an alternative. In 1994 the Royal Anthropological Institute advanced ,mixed origins', although such advocacy has gained little momentum. ,Mixed race' now competes with terms such as ,mixed heritage', ,dual heritage' and ,mixed parentage' amongst data users, and UK government usage also reflects this diversity in terminology. However, research indicates that the term of choice of most respondents in general and student samples of this population is ,mixed race'. Terms invoking just two groups , such as ,mixed parentage', ,dual heritage', and ,biracial', are preferred by few. While ,mixed origins' is likely to have a continuing niche role in professional practice, such as legal usage and assessment of health risks, it is premature to argue that the umbrella term ,mixed race' should be replaced by candidates that are not self-descriptors. Bruno Latour's editorial places such questions in a broader context as he draws attention to a lively debate on the biggest question of all, the essence of nature itself. In the context of an emergent multi-naturalism, has anthropological theory itself been ,decolonizing enough'? [source] PHYLOGEOGRAPHY OF THE GENUS SPONGITES (CORALLINALES, RHODOPHYTA) FROM CHILE,JOURNAL OF PHYCOLOGY, Issue 1 2008Rodrigo Vidal Both the records and the descriptions of the crustose species of coralline algae on the southeastern coast of South America are from the early 1900s. Unlike other algae species on the coast of Chile, the biogeography and distribution of crustose corallines have not been studied despite their abundance. Through recent studies, it has been determined that the genus Spongites is the most conspicuous genus along the rocky intertidal of the Chilean coasts. It is also common to the entire coast of the Southern Hemisphere; however, the relationship between species and the possible reasons for their distribution is unknown. We used nuclear and mitochondrial genetic markers and SEM observations of morphological characters to examine Spongites samples from the Southern Hemisphere and to establish the phylogeographic relationships of Chilean Spongites with specimens from other southern coasts. The combination of these analyses revealed the following: (i) a monophyletic clade that represents the Chilean Spongites and (ii) a paraphyletic clade for South African, New Zealand, and Argentine samples. Consequently, we postulate two nonexclusive hypotheses regarding the relationship of Spongites species in the Southern Hemisphere: (i) a complex history of extinction, speciation, and recolonization that might have erased original Gondwanan split patterns, and (ii) an Antarctic Peninsula origin for the Chilean Spongites species. [source] Recognition and palaeoclimatic implications of late Quaternary niche glaciation in eastern Lesotho,JOURNAL OF QUATERNARY SCIENCE, Issue 7 2009Stephanie C. Mills Abstract Geomorphic evidence of former glaciation in the high Drakensberg of southern Africa has proven controversial, with conflicting glacial and non-glacial interpretations suggested for many landforms. This paper presents new geomorphological, sedimentological and micromorphological data, and glacier mass-balance modelling for a site in the Leqooa Valley, eastern Lesotho, preserving what are considered to be moraines of a former niche glacier that existed during the Last Glacial Maximum (LGM). The geomorphology and macro-sedimentology of the deposits display characteristics of both active and passive transport by glacial processes. However, micromorphological analyses indicate a more complex history of glacial deposition and subsequent reworking by mass movement processes. The application of a glacier reconstruction technique to determine whether this site could have supported a glacier indicates a reconstructed glacier equilibrium line altitude (ELA) of 3136,m a.s.l. and palaeoglacier mass balance characteristics comparable with modern analogues, reflecting viable, if marginal glaciation. Radiocarbon dates obtained from organic sediment within the moraines indicate that these are of LGM age. The reconstructed palaeoclimatic conditions during the LGM suggest that snow accumulation in the Drakensberg was significantly higher than considered by other studies, and has substantial relevance for tuning regional climate models for southern Africa during the last glacial cycle. Copyright © 2009 John Wiley & Sons, Ltd. [source] Ancestry and divergence of subtropical montane forest isolates: molecular biogeography of the genus Abies (Pinaceae) in southern México and GuatemalaMOLECULAR ECOLOGY, Issue 10 2008JUAN P. JARAMILLO-CORREA Abstract The genus Abies has a complex history in southern México and Guatemala. In this region, four closely related species, Abies flinckii, A. guatemalensis, A. hickelii, and A. religiosa, are distributed in fragmented and isolated montane populations. Range-wide genetic variation was investigated across species using cytoplasmic DNA markers with contrasted inheritance. Variation at two maternally inherited mitochondrial DNA markers was low. All species shared two of the nine mitotypes detected, while the remaining seven mitochondrial DNA types were restricted to a few isolated stands. Mitochondrial genetic differentiation across taxa was high (GST = 0.933), it was not related to the taxonomic identity (amova; P > 0.05) of the populations, and it was not phylogeographically structured (GST , NST). In contrast, variation at three paternally inherited chloroplast DNA microsatellites was high. Chloroplast genetic differentiation was lower (GST = 0.402; RST = 0.547) than for mitochondrial DNA, but it was significantly related to taxonomy (amova; P < 0.001), and exhibited a significant phylogeographical structure (GST < RST). Different analyses of population structure indicated that A. flinckii was the most divergent taxon, while the remaining three species formed a relatively homogeneous group. However, a small number of the populations of these three taxa, all located at the limits of their respective ranges or in the Transverse Volcanic Belt, diverged from this main cluster. These trends suggest that the Mesoamerican Abies share a recent common ancestor and that their divergence and speciation is mainly driven by genetic drift and isolation during the warm interglacial periods. [source] Refugial isolation and secondary contact in the dyeing poison frog Dendrobates tinctoriusMOLECULAR ECOLOGY, Issue 14 2006BRICE P. NOONAN Abstract Recent palaeoclimactic research suggests that fluctuating environmental conditions throughout the Pleistocene of Amazonia occurred with previously unrecognized frequency. This has resulted in a theoretical shift from glacially influenced fluctuations to those driven by precessional rhythms. This theoretical revolution has a profound impact on expectations of biotic diversity within biogeographical regions that have long been based on the idea of large-scale landscape fragmentation associated with increased aridity and glacial cycles. Generally speaking, this shifts phylogeographical expectations from that of (i) large areas of sympatry of closely related (but not sister) species whose origins lie in separate refugia, and current distributions are the results of cyclic connectivity of those two refugia (refuge hypothesis), to that of (ii) fine scale genetic structure, often associated with elevation, and divergence well below expected speciation levels [disturbance,vicariance (DV) hypothesis]. To date there have been few tests of the expectations of the DV hypothesis based on empirical studies of Neotropical floral and faunal communities. Herein we examine phylogeographical structure of Dendrobates tinctorius, an amphibian species endemic to the uplands of the eastern Guiana Shield, based on sampling of 114 individuals from 24 localities. Phylogenetic, nested clade, and dispersal,vicariance (DIVA) analyses of cytochrome b sequence data reveal the presence of two mitochondrial lineages that are associated with previously identified western and eastern uplands of this area. The geographical distribution of mitochondrial haplotypes and the results of DIVA and coalescent analyses suggest that there has been extensive secondary contact between these lineages indicating a complex history of connectivity between these western and eastern highlands, supporting the predictions of the DV hypothesis. [source] Testing linear-theory predictions of galaxy formationMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 4 2000Ben Sugerman The angular momentum of galaxies is routinely ascribed to a process of tidal torques acting during the early stages of gravitational collapse, and is predicted from the initial mass distribution using second-order perturbation theory and the Zel'dovich approximation. We test this theory for a flat hierarchical cosmogony using a large N -body simulation with sufficient dynamic range to include tidal fields, allow resolution of individual galaxies, and thereby expand on previous studies. The predictions of linear collapse, linear tidal torque, and biased-peaks galaxy formation are applied to the initial conditions and compared with results for evolved bound objects. We find relatively good correlation between the predictions of linear theory and actual galaxy evolution. Collapse is well described by an ellipsoidal model within a shear field, which results primarily in triaxial objects that do not map directly to the initial density field. While structure formation from early times is a complex history of hierarchical merging, salient features are well described by the simple spherical-collapse model. Most notably, we test several methods for determining the turnaround epoch, and find that turnaround is successfully described by the spherical-collapse model. The angular momentum of collapsing structures grows linearly until turnaround, as predicted, and continues quasi-linearly until shell crossing. The predicted angular momentum for well-resolved galaxies at turnaround overestimates the true turnaround and final values by a factor of ,3, with a scatter of ,70 per cent, and only marginally yields the correct direction of the angular momentum vector. We recover the prediction that final angular momentum scales as mass to the 5/3 power. We find that mass and angular momentum also vary proportionally with peak height. In view of the fact that the observed galaxy collapse is a stochastic hierarchical and non-linear process, it is encouraging that the linear theory can serve as an effective predictive and analytic tool. [source] Genetic admixture, self-reported ethnicity, self-estimated admixture, and skin pigmentation among Hispanics and Native AmericansAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 4 2009Yann C. Klimentidis Abstract The relationship between ethnicity and biology is of interest to anthropologists, biomedical scientists, and historians in understanding how human groups are constructed. Ethnic self-identification in recently admixed groups such as Hispanics, African Americans, and Native Americans (NA) is likely to be complex due to the heterogeneity in individual admixture proportions and social environments within these groups. This study examines the relationships between self-identified ethnicity, self-estimated admixture proportions, skin pigmentation, and genetic marker estimated admixture proportions. These measures were assessed using questionnaires, skin color measurements, and genotyping of a panel of 76 ancestry informative markers, among 170 Hispanics and NAs from New Mexico, a state known for its complex history of interactions between people of NA and European (EU) ancestry. Results reveal that NAs underestimate their degree of EU admixture, and that Hispanics underestimate their degree of NA admixture. Within Hispanics, genetic-marker estimated admixture is better predicted by forehead skin pigmentation than by self-estimated admixture. We also find that Hispanic individuals self-identified as "half-White, half Hispanic" and "Spanish" have lower levels of NA admixture than those self-identified as "Mexican" and "Mexican American." Such results highlight the interplay between culture and biology in how individuals identify and view themselves, and have implications for how ethnicity and disease risk are assessed in a medical setting. Am J Phys Anthropol, 2009. © 2008 Wiley-Liss, Inc. [source] Sano di Pietro's Assunta polyptych for the Convent of Santa Petronilla in SienaRENAISSANCE STUDIES, Issue 4 2005Diana Norman Since its incorporation into Siena's first public art collection early in the nineteenth century, the provenance of Sano di Pietro's polyptych of The Virgin of the Assumption with Saints has been recognised as the Clarissan church of Santa Petronilla. To date, however, there has been very little comment as to the significance of the provenance of the altarpiece, particularly in relation to the choice of subject matter. This essay explores the complex history of this major Clarissan foundation in Siena, identifying its first location beyond Siena's principal northern gate of Porta Camollia and then describing its subsequent removal during the mid sixteenth century into the safety of the city itself and to the church where the altarpiece was discovered in 1810. Recognising that the presence of a Clarissan donor figure on the central painting of the polyptych provides plausible evidence that the altarpiece was commissioned for the original convent church, the essay further demonstrates how the circumstances of the foundation of Santa Petronilla in the second decade of the thirteenth century provide a key for the principal subject matter of the altarpiece. The remaining imagery of the altarpiece is then discussed in terms of its general relevance for a fifteenth-century community of Clarissan nuns and for the particular devotional concerns of the nuns of Santa Petronilla. It is argued that this late fifteenth-century Sienese altarpiece offers a revealing example of the way in which art commissioned by enclosed orders of female religious within Renaissance Italy could be closely related to their own concerns and priorities. (pp. 433,457) [source] Inter- and Extra-Indian Admixture and Genetic Diversity in Reunion Island Revealed by Analysis of Mitochondrial DNAANNALS OF HUMAN GENETICS, Issue 3 2009Vincent Dubut Summary Reunion Island is a French territory located in the western Indian Ocean. The genetic pattern of the Reunionese population has been shaped by contributions from highly contrasting regions of the world. Over the last 350 years, several migration waves and cultural and socio-economic factors have led to the emergence of six main ethnic groups in Reunion. India is one of the principal regions that contributed to the setting up of the Reunionese population. Diversity, demographic and admixture analyses were performed on mtDNA variation of the Reunionese of Indian ancestry, including the Malbar and Zarab ethnic groups, in order to question their history. Using a phylogeographical approach, we generated and analysed quantitative data on the contribution of the Indian parental populations. Furthermore, we showed that the settlement of Reunion Island by Indians did not involve a founder effect, except in the very beginning of the Reunionese settlement (at the end of the 17th century). The accuracy of our results was optimised by a re-evaluation of the classification of the Southern Asian mtDNA haplogroups. Finally, by comparing our results to a previous study dealing with the Reunionese population, we highlighted how ethno-historical data are critical for reconstructing the complex history of multiethnic populations. [source] Evolutionary history of the bank vole Myodes glareolus: a morphometric perspectiveBIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 3 2010RONAN LEDEVIN The bank vole experienced a complex history during the Quaternary. Repeated isolation in glacial refugia led to the differentiation of several lineages in less than 300 000 years. We investigated if such a recent differentiation led to a significant divergence of phenotypic characters between European lineages, which might provide insight into processes of intraspecific differentiation. The size and shape of the first and third upper molars, and first lower molar, of bank voles genetically attributed to different lineages were quantified using an outline analysis of their occlusal surface. The three teeth present similar trends of decreasing size towards high latitudes. This trend, the inverse of Bergmann's rule, is interpreted as the result of a balance between metabolic efficiency and food availability, favouring small body size in cold regions. Molar shape appeared to differ between lineages despite genetic evidence of suture zones. A mosaic pattern of evolution between the different teeth was evidenced. The analysis of such phenotypic features appears as a valuable complement to genetic analyses, providing a complementary insight into evolutionary processes, such as selective pressures, that have driven the differentiation of the lineages. It may further allow the integration of the paleontological dimension of the bank vole phylogeographic history. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 100, 681,694. [source] | |||||||||||||