Biology subjects

Fournier, R.

Publications and source records attributed to Fournier, R..

4 recordsLinked to original sources

bioRxiv2023

Social and genetic diversity in first farmers of central Europe

The Linearbandkeramik (LBK) Neolithic communities were the first to spread farming across large parts of central Europe, settling fertile regions from Ukraine to France during the second half of the 6th millennium BCE. The LBK had a high degree of material culture uniformity, albeit with regional differences in settlement patterns, subsistence, and mortuary practices. To date, ancient DNA data from LBK individuals have been generated for a limited number of locations and often in small sample sizes, making it challenging to study variation within and across sites. We report genome-wide data for 178 LBK individuals, from the Alfold Linearbankeramik Culture (ALPC) eastern LBK site of Polgar-Ferenci-hat in Hungary, the western LBK site of Nitra in Slovakia, and the enclosed western LBK settlement and massacre site of Schletz in Austria, as well as 42 LBK individuals from 18 other sites. We also report genome-wide data for 28 Early Neolithic Koros and Star[c]evo individuals from 13 sites, viewed as the predecessors of the LBK. We observe a higher percentage of western hunter-gatherer (WHG) admixture among individuals in the eastern LBK than in the far more widely distributed western LBK, showing that these two archaeologically distinct cultures also had different genetic trajectories. Most WHG-farmer mixture occurred just before the dawn of the LBK culture and there is no evidence that the WHG ancestry came systematically more from males or females. However, we do find strong genetic evidence for patrilocality among the LBK, extending previous findings based on isotopic analysis, with more genetic structure across sites on the male than on the female line, and a higher rate of within-site relatives for males. At Schletz we detect almost no first-degree relatives despite reporting data from almost every skeleton present at the site, showing that this massacre involved people from a large population, not a small community.

genetics↗

bioRxiv2022

Positive effects of projected climate change on post-disturbance forest regrowth rates in northeastern North American boreal forests

Forest anthropogenic and natural stand-replacing disturbances are increasing worldwide due to global change. Many uncertainties regarding the regeneration and growth of these young forests remain within the context of changing climate. In this study, we investigate the effects of climate, tree species composition, and other landscape-scale environmental variables upon boreal forest regrowth following clearcut logging in eastern Canada. Our main objective was to predict the effects of future climate changes upon post-logging forest height regrowth at a subcontinental scale using high spatial resolution remote sensing data. We modeled forest canopy height (estimated from airborne laser scanning [LiDAR] data over 20-m resolution virtual plots) as a function of time elapsed since the last clearcut along with climatic (i.e., temperature and moisture), tree species composition, and other environmental variables (e.g., topography and soil hydrology). Once trained and validated with [~]240,000 plots, the model that was developed in this study was used to predict potential post-logging canopy height regrowth at 20-m resolution across a 240,000 km2 area following scenarios depicting a range of projected changes in temperature and moisture across the region for 2041-2070. Our results predict an overall beneficial, but limited effect of projected climate changes upon forest regrowth rates in our study area. Stimulatory effects of projected climate change were more pronounced for conifer forests, with growth rates increasing between +5% and +50% over the study area, while mixed and broadleaved forests recorded changes that mostly ranged from -5% to +35%. Predicted increased regrowth rates were mainly associated with increased temperature, while changes in climate moisture had a minor effect. We conclude that such gains in regrowth rates may partially compensate for projected substantial increases in fire activity and other natural disturbances that are expected with climate change in these boreal forests.

ecology↗

bioRxiv2022

Haplotype-based inference of recent effective population size in modern and ancient DNA samples

1Individuals sharing recent ancestors are likely to co-inherit large identical-by-descent (IBD) genomic regions. The distribution of these IBD segments in a population may be used to reconstruct past demographic events such as effective population size variation, but accurate IBD detection is difficult in ancient DNA (aDNA) data and in underrepresented populations with limited reference data. In this work, we introduce an accurate method for inferring effective population size variation during the past ~2,000 years in both modern and aDNA data, called HapNe. HapNe infers recent population size fluctuations using either IBD sharing (HapNe-IBD) or linkage disequilibrium (HapNe-LD), which does not require phasing and can be computed in low coverage data, including data sets with heterogeneous sampling times. HapNe showed improved accuracy in a range of simulated demographic scenarios compared to currently available methods for IBD-based and LD-based inference of recent effective population size, while requiring fewer computational resources. We applied HapNe to several modern populations from the 1, 000 Genomes Project, the UK Biobank, the Allen Ancient DNA Resource, and recently published samples from Iron Age Britain, detecting multiple instances of recent effective population size variation across these groups.

genetics↗

bioRxiv2022

Cognitive exertion affects the appraisal of one's own and other people's pain

Correctly evaluating others pain is a crucial prosocial ability, especially relevant for the healthcare system. In clinical settings, caregivers assess their patients pain under high workload and fatigue, often while dealing with competing information/tasks. However, the effect played by such cognitive strain in the appraisal of others pain remains unclear. Following embodied accounts that posit a shared representational code between self and others states, it could be hypothesized that the representation of peoples pain might be influenced by cognitive exertion similarly to first-hand experiences. Fifty participants underwent one of two demanding tasks, involving either working memory (Experiment 1: N-Back task) or cognitive interference (Experiment 2: Stroop task). After each task, participants were exposed to painful laser stimulations at three intensity levels (low, medium, high), or video-clips of patients experiencing three intensity levels of pain (low, medium, high). Participants rated the intensity of each pain event on a visual analogue scale. We found that the two tasks influenced rating of both ones own and others pain, by decreasing the sensitivity to medium and high events. This was observed either when comparing the demanding condition to a control (Stroop), or when modelling linearly the difficulty/performance of each depleting task (N-Back). We provide converging evidence that cognitive exertion affects the subsequent appraisal of ones own and likewise others pain. Healthcare personnel should be aware that high workload might alter their cognitive abilities. Perspectivethis research shows that cognitive effort aftereffects impact negatively the assessment of of medium/high pain in others, reminiscently to what was observed in first-hand experiences. Healthcare professionals should be aware that high workload and severe cognitive fatigue could affect their diagnostic skills.

neuroscience↗