Circadian Cell-Cycle Progression: Cracking Open the Gate

In cyanobacteria cell division is intimately linked with the circadian cycle. Dong et al. (2010) now identify components of the circadian clock that regulate the formation of the midcell ring for cytokinesis, revealing a critical link between the circadian cycle and the control of cell division

The significance of climate fluctuations for lake level changes and shifts in subsistence economy during the late Neolithic (4300-2400 b.c. ) in central Europe

In the last decades, data on the economy and environment of the Neolithic period of lake dwellings (4300-2400 b.c.) in central Europe has increased considerably and also palaeoecological data on lake level fluctuations has been thoroughly elaborated. Lake shores were mainly settled during warm and rather dry climate periods which caused a fall in the lake levels. Nevertheless, there were strong and partly very short-term shifts in the economy during the lake-dwelling period. These can be recognised only because the settlement layers can be very precisely dated by dendrochronology. In this article we discuss in an interdisciplinary way the possible interrelations between climatic and economic changes. To explain the latter, we assume crop failures as the main reason, which caused intensified hunting and gathering. There are three different possibilities which might explain this: cold and wet summers, severe droughts during spring and summer, or local over-exploitation of soils in densely settled area

Burial condition is the most important factor for mtDNA PCR amplification success in Palaeolithic equid remains from the Alpine foreland

Faunal remains from Palaeolithic sites are important genetic sources to study preglacial and postglacial populations and to investigate the effect of climate change and human impact. Post mortem decay, resulting in fragmented and chemically modified DNA, is a key obstacle in ancient DNA analyses. In the absence of reliable methods to determine the presence of endogenous DNA in sub-fossil samples, temporal and spatial surveys of DNA survival on a regional scale may help to estimate the potential of faunal remains from a given time period and region. We therefore investigated PCR amplification success, PCR performance and post mortem damage in c. 47,000 to c. 12,000-year-old horse remains from 14 Palaeolithic sites along the Swiss Jura Mountains in relation to depositional context, tissue type, storage time and age, potentially influencing DNA preservation. The targeted 75 base pair mitochondrial DNA fragment could be amplified solely from equid remains from caves and not from any of the open dry and (temporary) wetland sites. Whether teeth are better than bones cannot be ultimately decided; however, both storage time after excavation and age significantly affect PCR amplification and performance, albeit not in a linear way. This is best explained by the—inevitable—heterogeneity of the data set. The extent of post mortem damage is not related to any of the potential impact factors. The results encourage comprehensive investigations of Palaeolithic cave sites, even from temperate regions

Mitochondrial d-loop variation, coat colour and sex identification of Late Iron Age horses in Switzerland

In the Celtic world, horses enjoyed a prominent position as status symbols and objects of veneration, yet little is known about these Celtic horses except that they were rather small. The Late Iron Age was a time defined by increasing inter-cultural contact between Celtic peoples and the Romans. This is, amongst other features, observable in the phenotypes of domestic livestock such as horses. Amongst the usually small animals, larger ones are rarely but regularly encountered in the archaeological record. We have investigated mitochondrial (mt) DNA d-loop diversity, sex and coat colour using bones from 34 horses of different size from three Swiss sites (Mormont, Basel-Gasfabrik, Aventicum) most of them dating from 150 to 50 BCE. The aim was to characterise the diversity of matrilineages and coat colourations of Iron Age horses, and to identify molecular sex. We detected eleven mt haplotypes clustering into six haplogroups (B, D, F, I, X2, X3) in the ancient dataset (n = 19). Large individuals were all male, but smaller stallions were also identified; molecular sexing confirmed and augmented to morphological results. The horses were bay, chestnut and black in colour, and spottings or dilutions were absent in all animals. With a simplified primer system to detect premature greying, white coats can be excluded as well. The limited colour range proposes selection for monochrome animals. Additionally, ancient matrilineages were compared to modern horses from regions appertaining to the Late Roman Republic and to European pony breeds. Based on Principal Component Analysis (haplotype frequencies) and FST-values (genetic distances) the mtDNA variation of the Iron Age horses investigated here has survived in modern European breeds, particularly in northern European ponies

The Basel-Gasfabrik research project: Addressing complex topics by an integrative approach

The late La Tène period site of Basel-Gasfabrik has been under investigation for more than a century. During that time, the unfortified settlement with its two cemeteries has yielded huge amounts of everyday and exceptional objects and features. Beginning in the mid-1970s, samples were systematically collected for scientific analyses during ongoing excavations, thus producing ideal preconditions for interdisciplinary research. In 2011-2014, the international research project “Approaching the living via the dead: human remains from the Late La Tène site Basel-Gasfabrik and their cultural-historical interpretations” addressed the multifarious ways in which the Iron Age community handled their deceased. The intense collaboration involved researchers from the Archäologische Bodenforschung Basel-Stadt and the universities of Basel (CH), Mainz and Freiburg i.Br. (D) and spanned eight disciplines: archaeology, archeoanthropology, archaeobotany, archaeozoology, geoarchaeology, biogeochemistry, molecular genetics and statistics. Research topics and theoretical frameworks were developed jointly as well as procedures to combine the disciplinary results in multistage processes in order to generate integrative syntheses of novel insights. The challenges and specific research potentials of the integrative approach may serve as a positive example for future interdisciplinary research project

Miners and mining in the Late Bronze Age: a multidisciplinary study from Austria

The extraction and processing of metal ores, particularly those of copper and tin, are regarded as among the principal motors of Bronze Age society. The skills and risks of mining lie behind the weapons, tools and symbols that drove political and ideological change. But we hear much less about the miners themselves and their position in society. Who were these people? Were they rich and special, or expendable members of a hard-pressed workforce? In this study the spotlight moves from the adits, slags and furnaces to the bones and seeds, providing a sketch of dedicated prehistoric labourers in their habitat. The Mauken miners were largely dependent on imported meat and cereals, and scarcely hunted or foraged the resources of the local forest. They seem to be the servants of a command economy, encouraged to keep their minds on the jo

On-site data cast doubts on the hypothesis of shifting cultivation in the Late Neolithic (c. 4300-2400 cal. BC): Landscape management as an alternative paradigm

This article brings together in a comprehensive way, and for the first time, on- and off-site palaeoenvironmental data from the area of the Central European lake dwellings (a UNESCO World Cultural Heritage Site since 2011). The types of data considered are as follows: high-resolution off-site pollen cores, including micro-charcoal counts, and on-site data, including botanical macro- and micro-remains, hand-collected animal bones, remains of microfauna, and data on woodland management (dendrotypology). The period considered is the late Neolithic (c. 4300–2400 cal. BC). For this period, especially for its earlier phases, discussions of land-use patterns are contradictory. Based on off-site data, slash-and-burn – as known from tropical regions – is thought to be the only possible way to cultivate the land. On-site data however show a completely different picture: all indications point to the permanent cultivation of cereals (Triticum spp., Hordeum vulgare), pea (Pisum sativum), flax (Linum usitatissimum) and opium-poppy (Papaver somniferum). Cycles of landscape use are traceable, including coppicing and moving around the landscape with animal herds. Archaeobiological studies further indicate also that hunting and gathering were an important component and that the landscape was manipulated accordingly. Late Neolithic land-use systems also included the use of fire as a tool for opening up the landscape. Here we argue that bringing together all the types of palaeoenvironmental proxies in an integrative way allows us to draw a more comprehensive and reliable picture of the land-use systems in the late Neolithic than had been reconstructed previously largely on the basis of off-site data

Ancient pigs reveal a near-complete genomic turnover following their introduction to Europe

Archaeological evidence indicates that pig domestication had begun by ~10,500 y before the present (BP) in the Near East, and mitochondrial DNA (mtDNA) suggests that pigs arrived in Europe alongside farmers ~8,500 y BP. A few thousand years after the introduction of Near Eastern pigs into Europe, however, their characteristic mtDNA signature disappeared and was replaced by haplotypes associated with European wild boars. This turnover could be accounted for by substantial gene flow from local Euro-pean wild boars, although it is also possible that European wild boars were domesticated independently without any genetic con-tribution from the Near East. To test these hypotheses, we obtained mtDNA sequences from 2,099 modern and ancient pig samples and 63 nuclear ancient genomes from Near Eastern and European pigs. Our analyses revealed that European domestic pigs dating from 7,100 to 6,000 y BP possessed both Near Eastern and European nuclear ancestry, while later pigs possessed no more than 4% Near Eastern ancestry, indicating that gene flow from European wild boars resulted in a near-complete disappearance of Near East ancestry. In addition, we demonstrate that a variant at a locus encoding black coat color likely originated in the Near East and persisted in European pigs. Altogether, our results indicate that while pigs were not independently domesticated in Europe, the vast majority of human-mediated selection over the past 5,000 y focused on the genomic fraction derived from the European wild boars, and not on the fraction that was selected by early Neolithic farmers over the first 2,500 y of the domestication process