Search Results
Abstract
The IsoMedIta database compiles 6304 stable isotope measurements (δ13C, δ15N, δ18O, δ34S, 87Sr/86Sr) from archaeological sites in medieval Italy (c. 500–1500 ce). The data is spatiotemporally referenced and includes bioarchaeological and paleo-environmental descriptions, alongside with other archaeological, biological, historical, environmental and technical metadata. IsoMedIta can be employed to address various historical questions at different spatial and temporal scales. It is also a resource for defining future research agendas and for heritage management.
Abstract
Sexual dimorphism in snake head/skull is poorly known, although analyses in other vertebrate groups have already pointed this kind of morphological difference. Herein we evaluated the existence of sexual dimorphism in the skull of Xenodon neuwiedii through Geometric Morphometrics (GM). We found that females have larger skulls than males using centroid size data. Considering the ventral view of the palatomaxillary apparatus, compared to females, males tend to have longer maxilla, ectopterygoid slightly laterally shifted, palatine slightly shorter, and longer pterygoid. For the dorsal view, males showed larger snout, more oblique frontoparietal suture, posterior region of the skull more tapered, larger supraoccipital, and larger and more oblique supratemporals. Xenodon neuwiedii showed static allometry only for the symmetric component of the dorsal view, with 9.7% of shape variation explained by size. The present study is the first evaluating and describing sexual dimorphism in skull shape for snakes independently of size. We compared our results with other studies and concluded that to accurately perform intraspecific analyses or to better understand sexual and/or natural selection, sexual dimorphism should be considered, even for structures (e.g. skull) that are traditionally not used for this purpose.
Abstract
The coming to office of Jair Bolsonaro in Brazil has brought to the fore the need to understand the rise of the far right and to come to terms with the conflicted legacies of more than a decade of rule under the Workers’ Party. This forum brings together six leading intellectuals from different traditions on the left and introduces their reflections on the contradictions and complexities of the Workers’ Party, the 2008 crisis, the June 2013 protests, the weakness of the Brazilian left, corruption, and on how to characterise Bolsonaro’s regime. Their interventions offer crucial insights that are relevant today not just to Brazil, or even Latin America, but to the politics of the left worldwide.
Abstract
Many studies on the diversity of the South American biota support the role of ecological and geological events as main drivers of species diversification. For many groups, geomorphological events are the key drivers of diversification, while the influence of Pleistocene climate oscillations is prominent for others. To precisely indicate which events were key for the development of the astonishing biodiversity in South America, studies on widely distributed species are paramount. One such species, the dwarf swamp frog Pseudopaludicola mystacalis (Leptodactylidae, Leiuperinae), is widely distributed in open habitats of South America and we herein investigate population differentiation and diversification in this species across its geographic range. We sequenced a 1374 bp mtDNA fragment from 64 specimens across 25 localities. We used population assignment and species delimitation methods to assess genetic structure and lineage limits across the species distribution. We estimated, for each lineage, intraspecific diversity, divergence times, and demographic histories. Our results recovered ten lineages with up to 5% of genetic divergence among them. Diversification occurred mainly during the Tertiary, suggesting that Miocene-Pliocene topographic events had a major influence on the diversification of P. mystacalis. Pleistocene climatic oscillations also played a role on evolutionary history of P. mystacalis, causing demographic changes in one lineage.
Abstract
The period from c. AD 900 to AD 1300 in southern Africa is characterized by transitions from small-scale Iron Age mixed economy communities to the beginnings of more intensive food production and eventually the emergence of complex polities. In Zambia, this coincides with the appearance of larger and more permanent agro-pastoralist villages that began participating in Indian Ocean trade networks. Unlike other parts of southern Africa where stone architecture became common, the predominance of wattle-and-daub type construction methods across Zambia have often impeded preservation of Iron Age activity areas. It has therefore been difficult to reconstruct how economic and land-use changes between the Early and Later Iron Ages impacted family and community relationships reflected in intra-site and intra-household spatial organization. Fibobe II, in the Mulungushi River Basin of Central Zambia, is a rare example of an Early-to-Mid Iron Age village site where these spatial patterns may be discernable due to preservation of activity spaces and vitrified remains of wattle-and-daub structures. This paper reports on new investigations following original testing of the site in 1979, confirming preservation of an Iron Age hut with distinct patterning of features, artifacts, and charcoal. These results reaffirm the unique nature of Fibobe II and indicate the potential for programs of household archaeology aimed at studying this important and understudied period in Zambian prehistory.