Palaeolithic Assemblages associated with Youngest Toba Tuff deposits from the Upper Gundlakamma river basin, Andhra Pradesh, India

Archaeological and geological remains associated with the Youngest Toba Tuff (YTT) deposits in India are seen as significant proxies for reconstructing 1) Initial modern human colonization of India and 2) Possible climatic impacts of the Toba super-eruption of 74 ka on Indian climate and hominin behaviour. In order to gain further insights into the environmental impacts and behavioural adaptations of human populations in India before and after the Toba eruption, we investigated archaeological horizons associated with the Toba ash beds along the Gundlakamma basin in Prakasam District, Andhra Pradesh, India. Here, lithic artefacts were identified below and above the YTT deposits. The YTT deposits in the Gundlakamma river basin has a maximum thickness of 50 cm, comparatively thinner than those at the better investigated valleys of the adjacent Jurreru and Sagileru in Andhra Pradesh and the Son, Madhya Pradesh, India. Our surveys indicate that the Palaeolithic assemblages associated with YTT deposits from the Gundlakamma river basin can provide significant insights on the issues and debates surrounding the Toba archaeology.Supplementary material at https://doi.org/10.6084/m9.figshare.c.5729449

Genomic adaptations of Campylobacter jejuni to long-term human colonization

Background Campylobacter is a genus of bacteria that has been isolated from the gastrointestinal tract of humans and animals, and the environments they inhabit around the world. Campylobacter adapt to new environments by changes in their gene content and expression, but little is known about how they adapt to long-term human colonization. In this study, the genomes of 31 isolates from a New Zealand patient and 22 isolates from a United Kingdom patient belonging to Campylobacter jejuni sequence type 45 (ST45) were compared with 209 ST45 genomes from other sources to identify the mechanisms by which Campylobacter adapts to long-term human colonization. In addition, the New Zealand patient had their microbiota investigated using 16S rRNA metabarcoding, and their level of inflammation and immunosuppression analyzed using biochemical tests, to determine how Campylobacter adapts to a changing gastrointestinal tract. Results There was some evidence that long-term colonization led to genome degradation, but more evidence that Campylobacter adapted through the accumulation of non-synonymous single nucleotide polymorphisms (SNPs) and frameshifts in genes involved in cell motility, signal transduction and the major outer membrane protein (MOMP). The New Zealand patient also displayed considerable variation in their microbiome, inflammation and immunosuppression over five months, and the Campylobacter collected from this patient could be divided into two subpopulations, the proportion of which correlated with the amount of gastrointestinal inflammation. Conclusions This study demonstrates how genomics, phylogenetics, 16S rRNA metabarcoding and biochemical markers can provide insight into how Campylobacter adapts to changing environments within human hosts. This study also demonstrates that long-term human colonization selects for changes in Campylobacter genes involved in cell motility, signal transduction and the MOMP; and that genetically distinct subpopulations of Campylobacter evolve to adapt to the changing gastrointestinal environment.

Anthropogenic transitions from forested to human-dominated landscapes in southern Macaronesia

The extinction of iconic species such as the dodo and the deforestation of Easter Island are emblematic of the transformative impact of human colonization of many oceanic islands, especially those in the tropics and subtropics. Yet, the interaction of prehistoric and colonial-era colonists with the forests and forest resources they encountered can be complex, varies between islands, and remains poorly understood. Long-term ecological records (e.g., fossil pollen) provide the means to understand these human impacts in relation to natural change and variability pre- and postcolonization. Here we analyze paleoecological archives in forested landscapes of the Canary Islands and Cabo Verde, first colonized approximately 2,400 to 2,000 and 490 y ago, respectively. We demonstrate sensitivity to regional climate change prior to human colonization, followed by divergent but gradual impacts of early human settlement. These contrast with more rapid transformation in the colonial era, associated with significant increases in anthropogenic pressures. In the Canary Islands, at least two native tree taxa became extinct and lowland thermophilous woodlands were largely converted to agricultural land, yet relictual subtropical laurel forests persisted with limited incursion of nonnative species. In Cabo Verde, in contrast, thermophilous woodlands were depleted and substituted by open landscapes and introduced woodlands. Differences between these two archipelagos reflect the changing cultural practices and societal interactions with forests and illustrate the importance of long-term data series in understanding the human footprint on island ecosystems, information that will be critically important for current and future forest restoration and conservation management practices in these two biodiversity hotspots.

Ecological Restoration in Gautam Buddha's Birthplace Lumbini

The historical information about natural vegetation of Lumbini is not clearly known. Modern day human colonization around Mayadevi temple could have been intensified after Khadga Samsher's visit to Lumbini in 1896, followed by the eradication of Malaria in the Tarai of Nepal around the 1950s. The dense human settlements around the Mayadevi temple (place where Buddha was born) was gradually shifted outside the area of Lumbini Development Trust (LDT) (16 x 4 km2 area), and the area was planted with a huge number of plant species. Hence, the forest within LDT is essentially a secondary forest without a scientific method of forest management (only plantation), as a result some species were not able to get naturally established and disappeared gradually. Studies indicated that there were around 354 species of plants species in LDT (Siwakoti, 2008) however, a recent vegetation survey (Tiwari, 1919) recorded only about 250 species including 39 tree species and other herbs and shrubs (the data is being produced, and needs second round survey to confirm). Some very common plant species have not been found from the region, indicating the heavy anthropogenic pressure including construction activities, grazing, fire, and plantation of trees without knowing microhabitat have taken the toll, and also by the encroachment of alien and invasive plant species both in terrestrial and aquatic environment. It is quite important to update the biodiversity, study regeneration of plant and animal species and management of invasive species in order to restore the natural ecosystems of Lumbini to develop it as both a sacred pilgrimage site and nature reserve. Ecosystem conservation and reintroduction at LDT could be done by following the strong reliance of Gautam Buddha's teaching about nature and life.

Experimental evolution of Vibrio cholerae: Identification of genes involved in motility in presence of polymyxin B

Vibrio cholerae is the bacteria responsible for the cholera disease and a natural inhabitant of aquatic environments. Biofilm formation is important for human colonization and environmental survival. Motility is essential for adhesion and biofilm formation by V. cholerae. In a previous study, we showed that motility and biofilm formation are altered in the presence of sub-inhibitory concentrations of polymyxin B in V. cholerae. In this study, we performed an experimental evolution to identify genes rescuing the motility in the presence of polymyxin B. Mutations in 5 genes have been identified: ihfA, vacJ (mlaA), mlaF, dacB and ccmH. The details of these mutations, their potential impact on the function of the proteins they encode and on the motility in presence of polymyxin B are discussed.

Collagen fingerprinting traces the introduction of caprines to island Eastern Africa

The human colonization of eastern Africa's near- and offshore islands was accompanied by the translocation of several domestic, wild and commensal fauna, many of which had long-term impacts on local environments. To better understand the timing and nature of the introduction of domesticated caprines (sheep and goat) to these islands, this study applied collagen peptide fingerprinting (Zooarchaeology by Mass Spectrometry or ZooMS) to archaeological remains from eight Iron Age sites, dating between ca 300 and 1000 CE, in the Zanzibar, Mafia and Comoros archipelagos. Where previous zooarchaeological analyses had identified caprine remains at four of these sites, this study identified goat at seven sites and sheep at three, demonstrating that caprines were more widespread than previously known. The ZooMS results support an introduction of goats to island eastern Africa from at least the seventh century CE, while sheep in our sample arrived one–two centuries later. Goats may have been preferred because, as browsers, they were better adapted to the islands' environments. The results allow for a more accurate understanding of early caprine husbandry in the study region and provide a critical archaeological baseline for examining the potential long-term impacts of translocated fauna on island ecologies.

Island Colonization and Environmental Sustainability in the Postglacial Mediterranean

Island environments present challenges to human colonization, but we have a poor understanding of how environmental difference drives heterogeneous patterns of insular settlement. In this paper, we assess which environmental and geographic variables positively or negatively affect the long-term sustainability of human settlement on islands. Using the postglacial Mediterranean basin as a case study, we assess the impact of area, isolation index, species richness, and net primary productivity (NPP) on patterns of island occupation for both hunter-gatherer and agropastoral populations. We find that models involving area most effectively accounts for sustainability in hunter-gatherer island settlement. The agropastoral data are noisier, perhaps due to culturally specific factors responsible for the distribution of the data; nonetheless, we show that area and NPP exert profound influence over sustainability of agropastoral island settlement. We conclude by suggesting that this relates to the capacity of these variables to impact demographic robusticity directly.