Repeated plague infections across six generations of Neolithic Farmers.

In the period between 5,300 and 4,900 calibrated years before present (cal. BP), populations across large parts of Europe underwent a period of demographic decline1,2. However, the cause of this so-called Neolithic decline is still debated. Some argue for an agricultural crisis resulting in the decline3, others for the spread of an early form of plague4. Here we use population-scale ancient genomics to infer ancestry, social structure and pathogen infection in 108 Scandinavian Neolithic individuals from eight megalithic graves and a stone cist. We find that the Neolithic plague was widespread, detected in at least 17% of the sampled population and across large geographical distances. We demonstrate that the disease spread within the Neolithic community in three distinct infection events within a period of around 120 years. Variant graph-based pan-genomics shows that the Neolithic plague genomes retained ancestral genomic variation present in Yersinia pseudotuberculosis, including virulence factors associated with disease outcomes. In addition, we reconstruct four multigeneration pedigrees, the largest of which consists of 38 individuals spanning six generations, showing a patrilineal social organization. Lastly, we document direct genomic evidence for Neolithic female exogamy in a woman buried in a different megalithic tomb than her brothers. Taken together, our findings provide a detailed reconstruction of plague spread within a large patrilineal kinship group and identify multiple plague infections in a population dated to the beginning of the Neolithic decline.

HyperPCM: Robust Task-Conditioned Modeling of Drug-Target Interactions.

A central problem in drug discovery is to identify the interactions between drug-like compounds and protein targets. Over the past few decades, various quantitative structure-activity relationship (QSAR) and proteo-chemometric (PCM) approaches have been developed to model and predict these interactions. While QSAR approaches solely utilize representations of the drug compound, PCM methods incorporate both representations of the protein target and the drug compound, enabling them to achieve above-chance predictive accuracy on previously unseen protein targets. Both QSAR and PCM approaches have recently been improved by machine learning and deep neural networks, that allow the development of drug-target interaction prediction models from measurement data. However, deep neural networks typically require large amounts of training data and cannot robustly adapt to new tasks, such as predicting interaction for unseen protein targets at inference time. In this work, we propose to use HyperNetworks to efficiently transfer information between tasks during inference and thus to accurately predict drug-target interactions on unseen protein targets. Our HyperPCM method reaches state-of-the-art performance compared to previous methods on multiple well-known benchmarks, including Davis, DUD-E, and a ChEMBL derived data set, and particularly excels at zero-shot inference involving unseen protein targets. Our method, as well as reproducible data preparation, is available at https://github.com/ml-jku/hyper-dti.

A Population-Based Study of Unfavorable Prognostic Factors Associated With Pyogenic Liver Abscess.

Background: Pyogenic liver abscess (PLA) is a rare entity that is associated with substantial mortality and morbidity. Our objective was to investigate variables associated with mortality and subsequent PLA in patients diagnosed with PLA in southern Sweden. Methods: We conducted a population-based observational study comprising all episodes of PLA that occurred between 2011 and 2020 in the county of Skåne, southern Sweden. The primary outcome was defined as all-cause 90-day mortality and the secondary outcome was defined as the occurrence of a subsequent PLA. Results: A total of 452 episodes of PLA occurred in 360 patients during the study period. The 90-day mortality rate was 16% (n = 58) and the subsequent PLA rate was 20% (n = 92). In a multivariable logistic regression model, female sex (odds ratio [OR], 2.0 [95% confidence interval {CI}, 1.1-3.9]), malignancy (OR, 3.7 [95% CI, 1.9-7.1]), liver failure (OR, 6.3 [95% CI, 2.7-14.5]), and polymicrobial findings (OR, 3.8 [95% CI, 2.2-6.9]) were associated with death within 90 days (P < .05). Male sex (OR, 2.1 [95% CI, 1.2-3.6]), malignancy (OR, 2.1 [95% CI, 1.3-3.6]), age (64-74 years: OR, 2.5 [95% CI, 1.3-4.8]), and chronic liver disease (OR, 3.0 [95% CI, 1.4-6.5]) were associated with the risk of subsequent PLA (P ≤ .01). Conclusions: Identifying different clinical variables associated with an unfavorable outcome may improve the management and treatment of patients with PLA and thus prevent the risk of death and subsequent PLA.

Genetic continuity, isolation, and gene flow in Stone Age Central and Eastern Europe.

The genomic landscape of Stone Age Europe was shaped by multiple migratory waves and population replacements, but different regions do not all show similar patterns. To refine our understanding of the population dynamics before and after the dawn of the Neolithic, we generated and analyzed genomic sequence data from human remains of 56 individuals from the Mesolithic, Neolithic, and Eneolithic across Central and Eastern Europe. We found that Mesolithic European populations formed a geographically widespread isolation-by-distance zone ranging from Central Europe to Siberia, which was already established 10,000 years ago. We found contrasting patterns of population continuity during the Neolithic transition: people around the lower Dnipro Valley region, Ukraine, showed continuity over 4000 years, from the Mesolithic to the end of the Neolithic, in contrast to almost all other parts of Europe where population turnover drove this cultural change, including vast areas of Central Europe and around the Danube River.

Increasing incidence of pyogenic liver abscess in Southern Sweden: a population-based study from 2011 to 2020.

BACKGROUND: Pyogenic liver abscess (PLA) is a rare but potentially life-threatening disease, and estimates suggest a gradual increase in the incidence during the last decades. The primary aim of this study was to report the incidence, trend and aetiology of PLA during a decade in Southern Sweden. METHODS: This was a population-based observational cohort study between 2011 and 2020 in Skåne, Southern Sweden. Data were retrieved from the Swedish National Board of Health and Welfare for all individuals diagnosed with liver abscess (K750) according to ICD-10 (International Statistical Classification of Diseases, 10th revision). RESULTS: A total of 456 episodes of PLA occurred in 364 patients during the study period. The median age of the first PLA episode was 71 years (range 3-97) and 57% (n = 206) were men. The mean incidence of all patients was 3.4/100,000 person-years (range 1.8-5.2). The incidence increased almost three times, from 1.8/100,000 person-years in 2011 to 5.2/100,000 person-years in 2020. Streptococcus species, Escherichia coli and Klebsiella species accounted for the vast majority of both mono- and polymicrobial findings in both blood and local abscess cultures. 16s rDNA added information about aetiology in 37% of episodes. CONCLUSION: The incidence of PLA increased during the study period, and Streptococcus spp., Klebsiella spp. and E. coli dominated both blood and local cultures. Despite antimicrobial therapy, pathogens could be found in local abscess cultures several weeks into treatment. Increased use of 16s rDNA in the management of PLA could be beneficial.

The ESSENCE-Questionnaire in Medical Records Screening for Neurodevelopmental Symptoms/Problems: Utility and Clinical Validity.

Purpose: Determine the prevalence of symptoms of neurodevelopmental problems (NDPs) with a semi-structured review of fourth grade students' medical records, its interrater agreement and validity as compared with clinical assessment. Methods: A school-based sample of 11-year-old children provided child health care (CHC) records and school health care (SHC) records. A pediatric neurologist, child psychiatrist and an adult psychiatrist scored the records, with the "Early Symptomatic Syndromes Eliciting Neurodevelopmental Clinical Examinations-Questionnaire" (ESSENCE-Q, 12 items scored 0-2, summary score range 0-24). Agreement was measured with model-based kappa and intraclass correlation coefficient (ICC). Ratings were validated against a multidisciplinary assessment involving a physician, psychologist, teacher- and parental behavioral rating scales rendering a clinical global impression severity rating (CGI-S, range 1-7) of NDPs. Results: Out of 223 participants, medical charts were available from 201, of whom 169 were rated by all three raters. Kappa agreement was moderate/strong (~0.8) for 7 of the 12 questionnaire items. Measured with the ICC, concordance in the summary score was good for agreement (~0.8) and excellent (~0.9) for consistency. Test-retest reliability was excellent (ICC = ~0.9). Area under the curve for the ESSENCE-Q in predicting clinical-level problems (CGI ≥4) was ~80% for all three raters, albeit with differing optimal cutoffs. Conclusion: Using the ESSENCE-Q as a template, NDPs appear to be common in medical records, are identified reliably, and predict clinical-level concern. Medical records screening may facilitate a structured review of medical records in work-ups or be applied in conjunction with other screening measures for neurodevelopmental disorders. However, differences in calibration currently preclude defining a universal cutoff for using the ESSENCE-Q for medical records screening.

The Effect of Botulinum Toxin Type A Injections on Stricture Formation, Leakage Rates, Esophageal Elongation, and Anastomotic Healing Following Primary Anastomosis in a Long- and Short-Gap Esophageal Atresia Model - A Protocol for a Randomized, Controlled, Blinded Trial in Pigs.

BACKGROUND: Esophageal atresia (EA) is a congenital malformation affecting 1:3000-4500 newborns. Approximately 15% have a long-gap EA (LGEA), in which case a primary anastomosis is often impossible to achieve. To create continuity of the esophagus patients instead have to undergo lengthening procedures or organ interpositions; methods associated with high morbidity and poor functional outcomes. Esophageal injections of Botulinum Toxin Type A (BTX-A) could enable primary anastomosis and mitigate stricture formation through decreased tissue tension. METHODS AND ANALYSIS: In this randomized controlled blinded animal trial, 24 pigs are divided into a long- or short-gap EA group (LGEA and SGEA, respectively) and randomized to receive BTX-A or isotonic saline injections. In the LGEA group, injections are given endoscopically in the esophageal musculature. After seven days, a 3 cm esophageal resection and primary anastomosis is performed. In the SGEA group, a 1 cm esophageal resection and primary anastomosis is performed, followed by intraoperative injections of BTX-A or isotonic saline. After 14 days, stricture formation, presence of leakage, and esophageal compliance is assessed using endoscopic and manometric techniques, and in vivo and ex vivo contrast radiography. Tissue elongation is evaluated in a stretch-tension test, and the esophagus is assessed histologically to evaluate anastomotic healing. ETHICS AND DISSEMINATION: The study complies with the ARRIVE guidelines for animal studies and has been approved by the Danish Animal Experimentation Council. Results will be published in peer-reviewed journals and presented at national and international conferences. HIGHLIGHTS: The optimal management of long-gap esophageal atresia remains controversialPrimary anastomosis could improve functional outcomes and reduce complicationsBotulinum Toxin Type A decreases tissue tension and could facilitate anastomosisReduced tension could further abate the risk for anastomotic stricture and leakageWe present a model to evaluate the method in long- and short-gap esophageal atresia.

Genome of Pestera Muierii skull shows high diversity and low mutational load in pre-glacial Europe.

Few complete human genomes from the European Early Upper Palaeolithic (EUP) have been sequenced. Using novel sampling and DNA extraction approaches, we sequenced the genome of a woman from "Pestera Muierii," Romania who lived ∼34,000 years ago to 13.5× coverage. The genome shows similarities to modern-day Europeans, but she is not a direct ancestor. Although her cranium exhibits both modern human and Neanderthal features, the genome shows similar levels of Neanderthal admixture (∼3.1%) to most EUP humans but only half compared to the ∼40,000-year-old Pestera Oase 1. All EUP European hunter-gatherers display high genetic diversity, demonstrating that the severe loss of diversity occurred during and after the Last Glacial Maximum (LGM) rather than just during the out-of-Africa migration. The prevalence of genetic diseases is expected to increase with low diversity; however, pathogenic variant load was relatively constant from EUP to modern times, despite post-LGM hunter-gatherers having the lowest diversity ever observed among Europeans.

Simulation capacity building in rural Indian hospitals: a 1-year follow-up qualitative analysis.

Introduction: The benefits of simulation-based medical training are well described. The most effective way to plant and scale simulation training in rural locations remains undescribed. We sought to plant simulation training programmes for anaesthesia emergencies in two rural Indian hospitals. Methods: Two Indian consultant anaesthetists without experience in medical simulation underwent a 3-day course at the Boston Children's Hospital's (BCH) Simulator Program. They returned to their institutions and launched simulation programmes with an airway manikin and mock patient monitor. The 1-year experience was evaluated using individual, in-depth interviews of simulation facilitators. Three staff members (responsible for facilitating medical simulations over the prior year) at two rural hospitals in India were interviewed. None attended the BCH training; instead, they received on-the-job training from the BCH-trained, consultant anaesthetist colleagues. Results: Successes included organisational adoption of simulation training with exercises 1 year after the initial BCH-training, increased interdisciplinary teamwork and improved clinical competency in managing emergencies. Barriers to effective, local implementation of simulation programmes fell into three categories: time required to run simulations, fixed and rigid roles, and variable resources. Thematic improvement requests were for standardised resources to help train simulation facilitators and demonstrate to participants a well-run simulation, in addition to context-sensitive scenarios. Conclusion: An in-person training of simulation facilitators to promote medical simulation programmes in rural hospitals produced ongoing simulation programmes 1 year later. In order to make these programmes sustainable, however, increased investment in developing simulation facilitators is required. In particular, simulation facilitators must be prepared to formally train other simulation facilitators, too.

Robust genome-wide ancestry inference for heterogeneous datasets: illustrated using the 1,000 genome project with 3D facial images.

Estimates of individual-level genomic ancestry are routinely used in human genetics, and related fields. The analysis of population structure and genomic ancestry can yield insights in terms of modern and ancient populations, allowing us to address questions regarding admixture, and the numbers and identities of the parental source populations. Unrecognized population structure is also an important confounder to correct for in genome-wide association studies. However, it remains challenging to work with heterogeneous datasets from multiple studies collected by different laboratories with diverse genotyping and imputation protocols. This work presents a new approach and an accompanying open-source toolbox that facilitates a robust integrative analysis for population structure and genomic ancestry estimates for heterogeneous datasets. We show robustness against individual outliers and different protocols for the projection of new samples into a reference ancestry space, and the ability to reveal and adjust for population structure in a simulated case-control admixed population. Given that visually evident and easily recognizable patterns of human facial characteristics co-vary with genomic ancestry, and based on the integration of three different sources of genome data, we generate average 3D faces to illustrate genomic ancestry variations within the 1,000 Genome project and for eight ancient-DNA profiles, respectively.

Illuminating Genetic Mysteries of the Dead Sea Scrolls.

The discovery of the 2,000-year-old Dead Sea Scrolls had an incomparable impact on the historical understanding of Judaism and Christianity. "Piecing together" scroll fragments is like solving jigsaw puzzles with an unknown number of missing parts. We used the fact that most scrolls are made from animal skins to "fingerprint" pieces based on DNA sequences. Genetic sorting of the scrolls illuminates their textual relationship and historical significance. Disambiguating the contested relationship between Jeremiah fragments supplies evidence that some scrolls were brought to the Qumran caves from elsewhere; significantly, they demonstrate that divergent versions of Jeremiah circulated in parallel throughout Israel (ancient Judea). Similarly, patterns discovered in non-biblical scrolls, particularly the Songs of the Sabbath Sacrifice, suggest that the Qumran scrolls represent the broader cultural milieu of the period. Finally, genetic analysis divorces debated fragments from the Qumran scrolls. Our study demonstrates that interdisciplinary approaches enrich the scholar's toolkit.

The Neolithic Pitted Ware culture foragers were culturally but not genetically influenced by the Battle Axe culture herders.

OBJECTIVES: In order to understand contacts between cultural spheres in the third millennium BC, we investigated the impact of a new herder culture, the Battle Axe culture, arriving to Scandinavia on the people of the sub-Neolithic hunter-gatherer Pitted Ware culture. By investigating the genetic make-up of Pitted Ware culture people from two types of burials (typical Pitted Ware culture burials and Battle Axe culture-influenced burials), we could determine the impact of migration and the impact of cultural influences. METHODS: We sequenced and analyzed the genomes of 25 individuals from typical Pitted Ware culture burials and from Pitted Ware culture burials with Battle Axe culture influences in order to determine if the different burial types were associated with different gene-pools. RESULTS: The genomic data show that all individuals belonged to one genetic population-a population associated with the Pitted Ware culture-irrespective of the burial style. CONCLUSION: We conclude that the Pitted Ware culture communities were not impacted by gene-flow, that is, via migration or exchange of mates. These different cultural expressions in the Pitted Ware culture burials are instead a consequence of cultural exchange.

Decentralization and Regionalization of Surgical Care: A Review of Evidence for the Optimal Distribution of Surgical Services in Low- and Middle-Income Countries.

BACKGROUND: While recommendations for the optimal distribution of surgical services in high-income countries (HICs) exist, it is unclear how these translate to resource-limited settings. Given the significant shortage and maldistribution of surgical workforce and infrastructure in many low- and middle-income countries (LMICs), the optimal role of decentralization versus regionalization (centralization) of surgical care is unknown. The aim of this study is to review evidence around interventions aimed at redistributing surgical services in LMICs, to guide recommendations for the ideal organization of surgical services. METHODS: A narrative-based literature review was conducted to answer this question. Studies published in English between 1997 and 2017 in PubMed, describing interventions to decentralize or regionalize a surgical procedure in a LMIC, were included. Procedures were selected using the Disease Control Priorities' (DCP3) Essential Surgery Package list. Intervention themes and outcomes were analyzed using a narrative, thematic synthesis approach. Primary outcomes included mortality, complications, and patient satisfaction. Secondary outcomes included input measures: workforce and infrastructure, and process measures: facility-based care, surgical volume, and referral rates. RESULTS: Thirty-five studies were included. Nine (33%) of the 27 studies describing decentralization showed an improvement in primary outcomes. The procedures associated with improved outcomes after decentralization included most obstetric, gynecological, and family planning services as well as some minor general surgery procedures. Out of 8 studies on regionalization (centralization), improved outcomes were shown for trauma care in one study and cataract extraction in one study. CONCLUSION: Interventions aimed at decentralizing obstetric care to the district hospital and health center levels have resulted in mortality benefits in several countries. However, more evidence is needed to link service distribution to patient outcomes in order to provide recommendations for the optimal organization of other surgical procedures in LMICs. Considerations for the optimal distribution of surgical procedures should include the acuity of the condition for which the procedure is indicated, anticipated case volume, and required level of technical skills, resources, and infrastructure. These attributes should be considered within the context of each country.

'We are all serving the same Ugandans': A nationwide mixed-methods evaluation of private sector surgical capacity in Uganda.

INTRODUCTION: Half of all Ugandans (49%) turn to the private or private-not-for-profit (PNFP) sectors when faced with illness, yet little is known about the capacity of these sectors to deliver surgical services. We partnered with the Ministry of Health to conduct a nationwide mixed-methods evaluation of private and PNFP surgical capacity in Uganda. METHODS: A standardized validated facility assessment tool was utilized to assess facility infrastructure, service delivery, workforce, information management, and financing at a randomized nationally representative sample of 16 private and PNFP hospitals. Semi-structured interviews were conducted to qualitatively explore facilitating factors and barriers to surgical, obstetric and anaesthesia (SOA) care. Hospitals walk-throughs and retrospective reviews of operative logbooks were completed. RESULTS: Hospitals had a median of 177 beds and two operating rooms. Ten hospitals (62.5%) were able to perform all Bellwether procedures (cesarean section, laparotomy and open fracture treatment). Thirty-day surgical volume averaged 102 cases per facility. While most hospitals had electricity, oxygen, running water, and necessary equipment, many reported pervasive shortages of blood, surgical consumables, and anesthetic drugs. Several themes emerged from the qualitative analysis: (1) geographic distance and limited transportation options delay reaching care; (2) workforce shortages impede the delivery of surgical care; (3) emergency and obstetric volume overwhelm the surgical system; (4) medical and non-medical costs delay seeking, reaching, and receiving care; and (5) there is poor coordination of care with insufficient support systems. CONCLUSION: As in Uganda's public sector, barriers to surgery in private and PNFP hospitals in Uganda are cross-cutting and closely tied to resource availability. Critical policy and programmatic developments are essential to build and strengthen Ugandan surgical capacity across all sectors.

The genomic ancestry of the Scandinavian Battle Axe Culture people and their relation to the broader Corded Ware horizon.

The Neolithic period is characterized by major cultural transformations and human migrations, with lasting effects across Europe. To understand the population dynamics in Neolithic Scandinavia and the Baltic Sea area, we investigate the genomes of individuals associated with the Battle Axe Culture (BAC), a Middle Neolithic complex in Scandinavia resembling the continental Corded Ware Culture (CWC). We sequenced 11 individuals (dated to 3330-1665 calibrated before common era (cal BCE)) from modern-day Sweden, Estonia, and Poland to 0.26-3.24× coverage. Three of the individuals were from CWC contexts and two from the central-Swedish BAC burial 'Bergsgraven'. By analysing these genomes together with the previously published data, we show that the BAC represents a group different from other Neolithic populations in Scandinavia, revealing stratification among cultural groups. Similar to continental CWC, the BAC-associated individuals display ancestry from the Pontic-Caspian steppe herders, as well as smaller components originating from hunter-gatherers and Early Neolithic farmers. Thus, the steppe ancestry seen in these Scandinavian BAC individuals can be explained only by migration into Scandinavia. Furthermore, we highlight the reuse of megalithic tombs of the earlier Funnel Beaker Culture (FBC) by people related to BAC. The BAC groups likely mixed with resident middle Neolithic farmers (e.g. FBC) without substantial contributions from Neolithic foragers.

Megalithic tombs in western and northern Neolithic Europe were linked to a kindred society.

Paleogenomic and archaeological studies show that Neolithic lifeways spread from the Fertile Crescent into Europe around 9000 BCE, reaching northwestern Europe by 4000 BCE. Starting around 4500 BCE, a new phenomenon of constructing megalithic monuments, particularly for funerary practices, emerged along the Atlantic façade. While it has been suggested that the emergence of megaliths was associated with the territories of farming communities, the origin and social structure of the groups that erected them has remained largely unknown. We generated genome sequence data from human remains, corresponding to 24 individuals from five megalithic burial sites, encompassing the widespread tradition of megalithic construction in northern and western Europe, and analyzed our results in relation to the existing European paleogenomic data. The various individuals buried in megaliths show genetic affinities with local farming groups within their different chronological contexts. Individuals buried in megaliths display (past) admixture with local hunter-gatherers, similar to that seen in other Neolithic individuals in Europe. In relation to the tomb populations, we find significantly more males than females buried in the megaliths of the British Isles. The genetic data show close kin relationships among the individuals buried within the megaliths, and for the Irish megaliths, we found a kin relation between individuals buried in different megaliths. We also see paternal continuity through time, including the same Y-chromosome haplotypes reoccurring. These observations suggest that the investigated funerary monuments were associated with patrilineal kindred groups. Our genomic investigation provides insight into the people associated with this long-standing megalith funerary tradition, including their social dynamics.

Four millennia of Iberian biomolecular prehistory illustrate the impact of prehistoric migrations at the far end of Eurasia.

Population genomic studies of ancient human remains have shown how modern-day European population structure has been shaped by a number of prehistoric migrations. The Neolithization of Europe has been associated with large-scale migrations from Anatolia, which was followed by migrations of herders from the Pontic steppe at the onset of the Bronze Age. Southwestern Europe was one of the last parts of the continent reached by these migrations, and modern-day populations from this region show intriguing similarities to the initial Neolithic migrants. Partly due to climatic conditions that are unfavorable for DNA preservation, regional studies on the Mediterranean remain challenging. Here, we present genome-wide sequence data from 13 individuals combined with stable isotope analysis from the north and south of Iberia covering a four-millennial temporal transect (7,500-3,500 BP). Early Iberian farmers and Early Central European farmers exhibit significant genetic differences, suggesting two independent fronts of the Neolithic expansion. The first Neolithic migrants that arrived in Iberia had low levels of genetic diversity, potentially reflecting a small number of individuals; this diversity gradually increased over time from mixing with local hunter-gatherers and potential population expansion. The impact of post-Neolithic migrations on Iberia was much smaller than for the rest of the continent, showing little external influence from the Neolithic to the Bronze Age. Paleodietary reconstruction shows that these populations have a remarkable degree of dietary homogeneity across space and time, suggesting a strong reliance on terrestrial food resources despite changing culture and genetic make-up.

Population genomics of Mesolithic Scandinavia: Investigating early postglacial migration routes and high-latitude adaptation.

Scandinavia was one of the last geographic areas in Europe to become habitable for humans after the Last Glacial Maximum (LGM). However, the routes and genetic composition of these postglacial migrants remain unclear. We sequenced the genomes, up to 57× coverage, of seven hunter-gatherers excavated across Scandinavia and dated from 9,500-6,000 years before present (BP). Surprisingly, among the Scandinavian Mesolithic individuals, the genetic data display an east-west genetic gradient that opposes the pattern seen in other parts of Mesolithic Europe. Our results suggest two different early postglacial migrations into Scandinavia: initially from the south, and later, from the northeast. The latter followed the ice-free Norwegian north Atlantic coast, along which novel and advanced pressure-blade stone-tool techniques may have spread. These two groups met and mixed in Scandinavia, creating a genetically diverse population, which shows patterns of genetic adaptation to high latitude environments. These potential adaptations include high frequencies of low pigmentation variants and a gene region associated with physical performance, which shows strong continuity into modern-day northern Europeans.