Ancient manuring practices pollute arable soils at the St Kilda World Heritage Site, Scottish North Atlantic

The impact of ancient fertilization practices on the biogeochemistry of arable soils on the remote Scottish island of Hirta, St Kilda was investigated. The island was relatively unusual in that the inhabitants exploited seabird colonies for food, enabling high population densities to be sustained on a limited, and naturally poor, soil resource. A few other Scottish islands, the Faeroes and some Icelandic Islands, had similar cultural dependence on seabirds. Fertilization with human and animal waste streams (mainly peat ash and bird carcases) on Hirta over millennia has led to over-deepened, nutrient-rich soils (plaggen). This project set out to examine if this high rate of fertilization had adversely impacted the soil, and if so, to determine which waste streams were responsible. Arable soils were considerably elevated in Pb and Zn compared to non-arable soils. Using Pb isotope signatures and analysis of the waste streams, it was determined that this pollution came from peat and turf ash (Pb and Zn) and from bird carcases (Zn). This was also confirmed by (13)C and (15)N analysis of the profiles which showed that soil organic matter was highly enriched in marine-derived C and N compared to non-arable soils. The pollution of such a remote island may be typical of other 'bird culture' islands, and peat ash contamination of marginal arable soils at high latitudes may be widespread in terms of geographical area, but less intense at specific locations due to lower population densities than on Hirta.

Ancient DNA reveals late survival of mammoth and horse in interior Alaska

Causes of late Quaternary extinctions of large mammals (" megafauna") continue to be debated, especially for continental losses, because spatial and temporal patterns of extinction are poorly known. Accurate latest appearance dates (LADs) for such taxa are critical for interpreting the process of extinction. The extinction of woolly mammoth and horse in northwestern North America is currently placed at 15,000-13,000 calendar years before present (yr BP), based on LADs from dating surveys of macrofossils (bones and teeth). Advantages of using macrofossils to estimate when a species became extinct are offset, however, by the improbability of finding and dating the remains of the last-surviving members of populations that were restricted in numbers or con-fined to refugia. Here we report an alternative approach to detect 'ghost ranges' of dwindling populations, based on recovery of ancient DNA from perennially frozen and securely dated sediments (sedaDNA). In such contexts, sedaDNA can reveal the molecular presence of species that appear absent in the macrofossil record. We show that woolly mammoth and horse persisted in interior Alaska until at least 10,500 yr BP, several thousands of years later than indicated from macrofossil surveys. These results contradict claims that Holocene survival of mammoths in Beringia was restricted to ecologically isolated high-latitude islands. More importantly, our finding that mammoth and horse overlapped with humans for several millennia in the region where people initially entered the Americas challenges theories that megafaunal extinction occurred within centuries of human arrival or were due to an extraterrestrial impact in the late Pleistocene.

Phylogenetic and phylogeographic analysis of the genus Orestias (Teleostei: Cyprinodontidae) in the southern Chilean Altiplano: The relevance of ancient and recent divergence processes in speciation

This study presents phylogenetic molecular data of the Chilean species of Orestias to propose an allopatric divergence hypothesis and phylogeographic evidence that suggests the relevance of abiotic factors in promoting population divergence in this complex. The results reveal that diversification is still ongoing, e.g. in the Ascotán salt pan, where populations of Orestias ascotanensis restricted to individual freshwater springs exhibit strong genetic differentiation, reflecting putative independent evolutionary units. Diversification of Orestias in the southern Altiplano may be linked to historical vicariant events and contemporary variation in water level; these processes may have affected the populations from the Plio-Pleistocene until the present.

The Death Cults of prehistoric Malta:Mysteries of the Ancient Ones

reprinted

Understanding how HR systems work: the role of HR philosophy and HR processes

Despite the proliferation of studies of HR systems, there are still substantial gaps in our understanding
of how such systems actually work. This article, by focusing on the neglected areas of HR philosophy
and HR processes in the composition of HR systems, and by using a qualitative, employee-centred
approach in the collection and analysis of data, provides new insights into the working of HR systems.
Using data from interviews with 56 knowledge workers employed in the information and
communications technology sector in Ireland and the UK, we explore employee-level reactions to two
different types of HR systems. We highlight the various ways in which HR processes interact with HR
practices and the different outcomes that may result, and we identify the key role of HR philosophy in
HR system operation.

Care and Management of Ancient Stone Monuments During Environmental Change

Ancient stone monuments (ASMs), such as standing stones and rock art panels, are powerful and iconic expressions of Britain’s rich prehistoric past that have major economic and tourism value. However, ASMs are under pressure due to increasing anthropogenic exposure and changing climatic conditions, which accelerate their rates of disrepair. Although scientific data exists on the integrity of stone monuments, most applies to “built” systems; therefore, additional work specific to ASMs in the countryside is needed to develop better-informed safeguarding strategies. Here, we use Neolithic and Bronze Age rock art panels across Northern England as a case study for delineating ASM management actions required to enhance monument preservation. The state of the rock art is described first, including factors that led to current conditions. Rock art management approaches then are described within the context of future environments, which models suggest to be more dynamic and locally variable. Finally, a Condition Assessment and Risk Evaluation (CARE) scheme is proposed to help prioritise interventions; an example of which is provided based on stone deterioration at Petra in Jordon. We conclude that more focused scientific and behavioural data, specific to deterioration mechanisms, are required for an ASM CARE scheme to be successful.