Simulating the evolution of height in the Netherlands in recent history

The Dutch have a remarkable history when it comes to height. From being one of the shortest European populations in the 19th Century, the Dutch grew some 20 cm and are currently the tallest population in the world. Wealth, hygiene, and diet are well-established contributors to this major increase in height. Some have suggested that natural selection may also contribute to the trend, but evidence is weak. Here, we investigate the potential role of natural selection in the increase in height through simulations. We first ask what if natural selection was solely responsible for the observed increase in height? If the increase in average height was fully due to natural selection on male height, then across six consecutive generations, men who were two standard deviation above average height would need to have eight times more children on average. If selection acted only through those who have the opportunity to reproduce, then reproduction would need to be restricted to the tallest third (37%) of the population in order to give rise to the stark increase in height over time. No linear relationship between height and child mortality is able to account for the increase over time. We then present simulations based on previously observed estimates of partnership, mortality, selection and heritability and show that natural selection had a negligible effect (estimates from 0.07 to 0.36 cm) on the increase in height in the period 1850 to 2000. Our simulations highlight the plasticity of height and how remarkable the trend in height is in evolutionary terms. Only by using a combination of methods and insights from different disciplines, including biology, demography, and history are we potentially able to address how much of the increase in height is due to natural selection versus other causes.</p

Proof of principle : the adaptive geometry of social foragers

Acknowledgments We thank Cape Nature for permission to undertake the study. We thank Dr Matt Grove and two anonymous referees for comments and suggestions that improved the manuscript substantially. This research was funded by grants from the Leakey Foundation, National Science and Engineering Research Council, Canada to S.P.H. and L.B., and by the National Research Foundation, South Africa to S.P.H. His co-authors dedicate this paper to the memory of P.M.R.C. The authors declare no competing interests.Peer reviewedPostprin

Social Structure Facilitated the Evolution of Care-giving as a Strategy for Disease Control in the Human Lineage

Humans are the only species to have evolved cooperative care-giving as a strategy for disease control. A synthesis of evidence from the fossil record, paleogenomics, human ecology, and disease transmission models, suggests that care-giving for the diseased evolved as part of the unique suite of cognitive and socio-cultural specializations that are attributed to the genus Homo. Here we demonstrate that the evolution of hominin social structure enabled the evolution of care-giving for the diseased. Using agent-based modeling, we simulate the evolution of care-giving in hominin networks derived from a basal primate social system and the three leading hypotheses of ancestral human social organization, each of which would have had to deal with the elevated disease spread associated with care-giving. We show that (1) care-giving is an evolutionarily stable strategy in kin-based cooperatively breeding groups, (2) care-giving can become established in small, low density groups, similar to communities that existed before the increases in community size and density that are associated with the advent of agriculture in the Neolithic, and (3) once established, care-giving became a successful method of disease control across social systems, even as community sizes and densities increased. We conclude that care-giving enabled hominins to suppress disease spread as social complexity, and thus socially-transmitted disease risk, increased

Individual-level movement bias leads to the formation of higher-order social structure in a mobile group of baboons

Sherpa Romeo green journal. Open access article. Creative Commons Attribution 4.0 International LIcense (CC BY 4.0) applies.In mobile social groups, influence patterns driving group movement can vary between democratic and despotic. The arrival at any single pattern of influence is thought to be underpinned by both environmental factors and group composition. To identify the specific patterns of influence driving travel decision-making in a chacma baboon troop, we used spatially explicit data to extract patterns of individual movement bias. We scaled these estimates of individual-level bias to the level of the group by constructing an influence network and assessing its emergent structural properties. Our results indicate that there is heterogeneity in movement bias: individual animals respond consistently to particular group members, and higher-ranking animals are more likely to influence the movement of others. This heterogeneity resulted in a group-level network structure that consisted of a single core and two outer shells. Here, the presence of a core suggests thatasetofhighlyinterdependentanimalsdroveroutinegroup movements. These results suggest that heterogeneity at the individual level can lead to group-level influence structures, and that movement patterns in mobile social groups can add to the exploration of both how these structures develop (i.e. mechanistic aspects) and what consequences they have for individual- and group-level outcomes (i.e. functional aspects).Ye

Sick and tired : sickness behaviour, polyparasitism and food stress in a gregarious mammal

Although sickness behaviour in response to non-lethal parasites has been documented in wild animals, it remains unclear how social and environmental stress might also shape an animal’s behavioural response to parasitism, nor do we know whether simultaneous infection with more than one parasite changes the way animals respond. Here, we combine physiological, environmental, behavioural and parasite measures to investigate behavioural responses to infection in wild vervet monkeys (Chlorocebus pygerythrus) living in a semi-arid region of South Africa. We quantified both activity budget and behavioural predictability to investigate the occurrence of sickness behaviour and infection with two non-lethal gastrointestinal parasite genera. Higher parasite load was linked to an increase in the time spent resting. However, the nature of the relationship with other behaviours was contingent on both the parasite genus in question and parasite species interacted, highlighting the importance of considering co-infection. Overall, food availability was the dominant predictor of behavioural change suggesting that, for monkeys living in a more extreme environment, coping with ecological stress may override the ability to modulate behaviour in response to other physiological stressors. Our findings provide insight into how animals living in harsh environments find ways to cope with parasite infection, avoidance and transmission. SIGNIFICANCE STATEMENT : Sickness behaviour is a suite of behaviours that occur in response to infection that may serve as an adaptive response to cope with infection. For wild animals, the ability to express sickness behaviour will be modulated by the presence of other competing stressors. Hence, the patterns shown are likely to be more complex than under captive conditions, which is where most of our knowledge of sickness behaviour comes from. Using physiological, environmental, behavioural and parasite measures, we demonstrate that although vervet monkeys (Chlorocebus pygerythrus) living in a semi-arid region of South Africa do exhibit sickness behaviours, this is contingent on the parasite genus in question. Further, food availability was the dominant predictor of behavioural change suggesting that, for monkeys living in a more extreme environment, coping with severe ecological stress may override the ability to express sickness behaviour in an adaptive fashion.National Research Foundation (South Africa), Natural Science and Engineering Research Council of Canada (NSERC) Discovery Grants, the Canada Research Chairs Program, a Leakey Foundation Franklin Mosher Baldwin Memorial Fellowship and a Senior Post-doctoral Fellowship at the University of Pretoria.http://link.springer.com/journal/265hj2022Mammal Research Institut

A Large Scale Survey of NGC1333

We observed the clustered star forming complex NGC1333 with the BIMA and FCRAO telescopes in the transitions HCO+(1-0) and N2H+(1-0) over an 11'x11' area with resolution ~10" (0.015pc). The N2H+ emission follows very closely the submillimeter dust continuum emission, while HCO+ emission appears more spatially extended and also traces outflows. We have identified 93 N2H+ cores using the CLUMPFIND algorithm, and we derive N2H+ core masses between 0.05 and 2.5M_sun, with uncertainties of a factor of a few, dominated by the adopted N2H+ abundance. From a comparison with virial masses, we argue that most of these N2H+ cores are likely to be bound, even at the lowest masses, suggesting that the cores do not trace transient structures, and implies the entire mass distribution consists of objects that can potentially form stars. We find that the mass distribution of N2H+ cores resembles the field star IMF, which suggests that the IMF is locked in at the pre-stellar stage of evolution. We find that the N2H+ cores associated with stars identified from Spitzer infrared images have a flat mass distribution. This might be because lower mass cores lose a larger fraction of their mass when forming a star. Even in this clustered environment, we find no evidence for ballistic motions of the cores relative to their lower density surroundings traced by isotopic CO emission, though this conclusion must remain tentative until the surroundings are observed at the same high resolution as the N2H+.Comment: 35 pages, 13 figure

Initial conditions for star formation in clusters: physical and kinematical structure of the starless core Oph A-N6

We present high spatial (<300 AU) and spectral (0.07 km/s) resolution Submillimeter Array observations of the dense starless cluster core Oph A-N6, in the 1 mm dust continuum and the 3-2 line of N2H+ and N2D+. The dust continuum observations reveal a compact source not seen in single-dish observations, of size ~1000 AU and mass 0.005-0.01 M\odot. The combined line and single-dish observations reveal a core of size 3000 \times 1400 AU elongated in a NW-SE direction, with almost no variation in either line width or line center velocity across the map, and very small non-thermal motions. The deuterium fraction has a peak value of ~0.15 and is >0.05 over much of the core. The N2H+ column density profile across the major axis of Oph A-N6 is well represented by an isothermal cylinder, with temperature 20 K, peak density 7.1 \times 10^6 cm^{-3}, and N2H+ abundance 2.7 \times 10^{-10}. The mass of Oph A-N6 is estimated to be 0.29 M\odot, compared to a value of 0.18 M\odot from the isothermal cylinder analysis, and 0.63 M\odot for the critical mass for fragmentation of an isothermal cylinder. Compared to isolated low-mass cores, Oph A-N6 shows similar narrow line widths and small velocity variation, with a deuterium fraction similar to "evolved" dense cores. It is significantly smaller than isolated cores, with larger peak column and volume density. The available evidence suggests Oph A-N6 has formed through the fragmentation of the Oph A filament and is the precursor to a low-mass star. The dust continuum emission suggests it may already have begun to form a star.Comment: 42 pages, 12 figures, accepted by Ap

Evaluating the Lethal Means of Non-Fatal Suicide Attempts Presenting to Washington State Emergency Departments Before and During the COVID-19 Pandemic

Thesis (Master's)--University of Washington, 2022Introduction: During the COVID-19 pandemic, concerns about increasing mental health conditions have emerged due to intersecting stressors associated with COVID-19 morbidity and mortality as well as disease mitigation efforts such as stay-at-home orders, school closures, and social distancing. However, little is known regarding the COVID-19 pandemic’s impact on suicidal behavior in Washington. Methods: This observational longitudinal study utilized 7,765 Washington Emergency Department (ED) visit records from 2019 to 2021 to describe the lethal means utilized for non-fatal suicide attempts and investigate if the utilization of lethal means for suicide attempts has changed during the COVID-19 pandemic. Data on lethal mean utilization were collected from visit records using a novel, automated classification approach leveraging ICD-10 diagnostic codes and clinical free-text fields. Results: Poisoning was the most identified lethal mean among non-fatal suicide attempt visit records during the study period (n = 5833), followed by Other (n = 1010), No Lethal Mean detected (n = 601), Suffocation (n = 356), and Firearms (n = 68). There were a few instances where non-fatal suicide attempt visit counts and proportion of all ED visits increased relative to before the COVID-19 pandemic such as for poisoning (+13.7%, Visit Ratio = 1.23 [1.1, 1.37]), other (+28.8%, Visit Ratio = 1.39 [1.04, 1.86]), and total suicide attempts (+16.3%, 1.26 [1.14, 1.39]) during Winter 2021 (2/21 – 3/20/2021). School age youth (12 – 17 years) appeared to be most impacted as non-fatal suicide attempts accounted for the largest share of ED visits (across all subgroups examined), and they experienced the greatest number of statistically significant elevated visit ratios for suicide attempts during the COVID-19 pandemic (n = 12). Conclusions: This study developed a novel approach to identify the utilization of lethal means for non-fatal suicide attempts using population-based ED data. This approach could be valuable in monitoring real-time changes in population-level suicidal behaviors and evaluating the impact of lethal mean restriction policies

Spatial simulations of infectious disease: environment, behaviour, and their interaction in a primate population

Recent trends in emerging and re-emerging human infectious disease indicate that zoonotic diseases are on the rise (e.g., SARS, Swine Flu, Bird flu, Ebola, and Lyme disease), creating large economic and social costs. The increasingly dominant role that humans are playing in changing the environment is thought to be a leading cause for this increasing emergence. In this dissertation, I investigated the effects of landscape level changes on a specific host parasite system: red colobus (Procolobus rufomitratus) and gastrointestinal nematode parasites within Kibale National Park, Uganda landscape. I first quantified the variation in forest recovery in the region and their effects on the resident primate community. Next, I explored the link between forest structure and red colobus movement patterns by 1) developing a new measure of habitat use (STBBD), quantifying the predilection of an animal to revisit habitat patches, and 2) testing between several hypotheses to explain red colobus movement patterns. Finally, I developed a spatially-explicit epidemiological model using the insights developed in forest structure and red colobus movement patterns. This model was used to assess the disease-related consequences of habitat fragmentation, quantifying the relative effects of the extent of habitat and its spatial configuration. My epidemiological model illustrate that by taking advantage of advances in spatial data analysis it is possible to expand the range of questions that can be addressed, developing a more spatially explicit understanding of infectious disease. I also argue that by including specific landscapes and host behaviours, these approaches increase the relevance of the results for disease management, allowing managers and researches to take a more proactive role and assess the effects of planned or predicted landscape changes on host-parasite dynamics.Les tendances récentes dans les maladies infectieuses humaines émergentes et réémergentes indiquent que les maladies zoonotiques sont à la hausse (par exemple, le SRAS, la grippe porcine, la grippe aviaire, le virus Ebola et la maladie de Lyme), générant d'importants coûts économiques et sociaux. Le rôle de plus en plus dominant que les humains jouent dans la transformation de l'environnement est considéré comme une des principales causes de cette émergence. Dans cette thèse, j'ai étudié les effets des changements au niveau du paysage sur un système hôte-parasite spécifique : le colobe roux (Procolobus rufomitratus) et les nématodes gastro-intestinaux dans le parc national de Kibale, en Ouganda. J'ai d'abord quantifié la variation de la reconstitution de la forêt dans la région et leurs effets sur la communauté des primates. Par la suite, j'ai exploré le lien entre la structure de la forêt et les habitudes de déplacement des colobes roux par 1) l'élaboration d'une nouvelle mesure de l' utilisation de l'habitat (ST-BBD), la quantification de la prédilection d'un animal de revisiter des parcelles d'habitat, et 2 ) des tests avec plusieurs hypothèses afin d'expliquer les habitudes de déplacement des colobes roux. Enfin, j'ai développé un modèle épidémiologique spatialement explicite en utilisant les idées développées dans la structure de la forêt et l'utilisation du territoire des colobes roux. Ce modèle a été utilisé pour évaluer les conséquences des maladies liées à la perte d'habitat, en quantifiant les effets relatifs de la fragmentation et de l'ampleur de la perte. Mes modèles épidémiologiques montrent que, en prenant avantage de l'amélioration des techniques d'analyse spatiale, il est possible d'élargir l'éventail de questions qui peuvent être abordées, en développant une compréhension plus spatialement explicite des maladies infectieuses. Je soutiens également que, en sélectionnant spécifiquement des paysages et des comportements de l'hôte, ces approches augmentent la pertinence des résultats à la gestion de la maladie, permettant aux gestionnaires et aux chercheurs de jouer un rôle plus proactif et d'évaluer les effets des changements prévus ou planifiés du paysage sur la dynamique hôte-parasite