Adaptive Value of Phenological Traits in Stressful Environments: Predictions Based on Seed Production and Laboratory Natural Selection

Phenological traits often show variation within and among natural populations of annual plants. Nevertheless, the adaptive value of post-anthesis traits is seldom tested. In this study, we estimated the adaptive values of pre- and post-anthesis traits in two stressful environments (water stress and interspecific competition), using the selfing annual species Arabidopsis thaliana. By estimating seed production and by performing laboratory natural selection (LNS), we assessed the strength and nature (directional, disruptive and stabilizing) of selection acting on phenological traits in A. thaliana under the two tested stress conditions, each with four intensities. Both the type of stress and its intensity affected the strength and nature of selection, as did genetic constraints among phenological traits. Under water stress, both experimental approaches demonstrated directional selection for a shorter life cycle, although bolting time imposes a genetic constraint on the length of the interval between bolting and anthesis. Under interspecific competition, results from the two experimental approaches showed discrepancies. Estimation of seed production predicted directional selection toward early pre-anthesis traits and long post-anthesis periods. In contrast, the LNS approach suggested neutrality for all phenological traits. This study opens questions on adaptation in complex natural environment where many selective pressures act simultaneously

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Inférence des processus démographiques passés à partir de différents marqueurs génétiques pour des populations humaines aux modes de vie contrastés.

Reconstructing the demographic History of human populations remains a strongly investigated issue in many disciplines. In particular, the transition from hunting and gathering to plant and animal domestication during the Neolithic period is widely assumed by paleoanthropologists and archeologists to have driven recent human population expansions. Conversely, although demographic changes leave footprints on genetic polymorphism, few population genetic studies have found traces of Neolithic expansions in the current repartition of human genetic diversity, pointing rather toward more ancient (i.e. Middle or Upper Paleolithic) expansions. Here, we inferred the demographic history of multiple African and Eurasian populations with contrasted life styles, using several coalescent-based methods applied to different types of genetic markers. The analyses on autosomal and mitochondrial sequences revealed a Paleolithic expansion event for most populations, except for the ancestors of contemporary African hunter-gatherers. Using autosomal microsatellites, we also inferred a more recent expansion event, likely concomitant with the Neolithic transition, in sedentary farmer but not in nomadic herder populations. We also found that, in some cases, isolation and migration patterns can have an impact on coalescent-based inferences. Finally, using simulated data, we confirmed the fact that, when two consecutive expansions occur, sequence data generally give information about the oldest one while microsatellite data can bring information about the most recent one.Reconstruire l’histoire démographique de notre espèce est un défi pour de nombreuses disciplines. Notamment, l’émergence de l’agriculture et de l’élevage au Néolithique est largement considérée par les archéologues et paléoanthropologues comme le déclencheur des grandes expansions démographiques. A l’inverse, peu d’études de génétique des populations ont détecté des traces d’expansions néolithiques dans le polymorphisme génétique actuel, soulignant plutôt des expansions plus anciennes (Paléolithique moyen ou supérieur). Ici, nous avons inféré l’histoire démographique de populations d’Afrique et d’Eurasie aux modes de vie contrastés, à l’aide de plusieurs méthodes issues de la théorie de la coalescence appliquées à différents marqueurs génétiques. L’analyse de séquences autosomales et mitochondriales révèle une première expansion au Paléolithique, excepté chez les ancêtres des chasseurs-cueilleurs actuels en Afrique. Grâce aux microsatellites autosomaux, nous démontrons également une deuxième phase d’expansion plus récente, compatible avec la transition néolithique, chez les populations d’agriculteurs sédentaires mais pas chez les populations d’éleveurs nomades. Nous avons également montré que les processus de migration et d’isolation peuvent influencer dans une certaine mesure les inférences démographiques pour certaines populations. Enfin des analyses sur données simulées nous ont permis de tester les méthodes utilisées et ont confirmé le fait que, dans le cas de deux expansions successives au cours du temps, les données de séquences tendront à nous renseigner sur l’évènement le plus ancien tandis que les données microsatellites dévoileront l’évènement le plus récent

Inference of past historical events using ABC and MCMC methods on population genomics data sets. Applications to human populations

International audienceNew computer-intensive estimation techniques such as Approximate Bayesian Computation (ABC) and Monte Carlo Markov chains (MCMC) allows inferring unknown parts of the history of species from contemporary population genetics and genomics data. I will illustrate these possibilities with several examples. In this context, we performed a study on worldwide human populations, in which by applying MCMC methods on a large set of populations with different lifestyles (farmers, herder and hunter-gatherers), we were able to show that these lifestyles strongly impacted the expansion patterns of these populations: farmers show strong expansion signals, herders weak expansion and hunter-gatherers no expansion at all. Moreover we showed that rapidly mutating markers like microsatellites allowed us to infer the recent Neolithic expansion, while slowly mutating markers like sequences allowed us to infer a more ancient Paleolithic expansion. The validity of this approach was verified through a simulation study.More recently, we developed a parametric ABC method for whole-genome sequencing data. We studied which combinations of summary statistics allow best to infer the demographic processes occurring in the populations under study. We applied this method to human populations from the 1000 Genome project. Our first results show that we can infer contrasted results when comparing Eurasian and African populations

Grandmothering and cognitive resources are required for the emergence of menopause and extensive post-reproductive lifespan.

Menopause, the permanent cessation of ovulation, occurs in humans well before the end of the expected lifespan, leading to an extensive post-reproductive period which remains a puzzle for evolutionary biologists. All human populations display this particularity; thus, it is difficult to empirically evaluate the conditions for its emergence. In this study, we used artificial neural networks to model the emergence and evolution of allocation decisions related to reproduction in simulated populations. When allocation decisions were allowed to freely evolve, both menopause and extensive post-reproductive life-span emerged under some ecological conditions. This result allowed us to test various hypotheses about the required conditions for the emergence of menopause and extensive post-reproductive life-span. Our findings did not support the Maternal Hypothesis (menopause has evolved to avoid the risk of dying in childbirth, which is higher in older women). In contrast, results supported a shared prediction from the Grandmother Hypothesis and the Embodied Capital Model. Indeed, we found that extensive post-reproductive lifespan allows resource reallocation to increase fertility of the children and survival of the grandchildren. Furthermore, neural capital development and the skill intensiveness of the foraging niche, rather than strength, played a major role in shaping the age profile of somatic and cognitive senescence in our simulated populations. This result supports the Embodied Capital Model rather than the Grand-Mother Hypothesis. Finally, in simulated populations where menopause had already evolved, we found that reduced post-reproductive lifespan lead to reduced children's fertility and grandchildren's survival. The results are discussed in the context of the evolutionary emergence of menopause and extensive post-reproductive life-span

Talleres de juegos cooperativos para organizaciones sociales

Los Talleres de Juegos Cooperativos son una propuesta de extensión y de trabajo articulada entre el Equipo de Juegos Cooperativosdel Instituto Académico Pedagógico de Ciencias Sociales y el Instituto de Extensión de la Universidad Nacional de Villa María, a la vez de contar con la participación de docentes del grupo APASA la Universidad Nacional de Río Cuarto. En consecuencia, el ciclo de talleres inauguró su primera jornada el día 27 de abril del 2018 en el Patrimonio Histórico de Villa María, la actividad fue de carácter gratuito y contó con la presencia de ciento veinte participantes. El objetivo fundamental que dio origen a estos talleres, fue la posibilidad de acompañar y fortalecer las intervenciones comunitarias desde la Universidad, a partir de brindar herramientas lúdicas basadas en perspectivas críticas y en la propuesta del enfoque de “Juegos Cooperativos”, a aquellas organizaciones sociales y personas que en su quehacer cotidiano trabajan en espacios recreativos con niñas, niños o adolescentes. De acuerdo a ello, el primer taller se enfocó en la reflexión y desnaturalización de los sentidos que subyacen en los juegos; estos últimos, comprendidos como productos culturales que visibilizan valores e idiosincrasias sociales-históricas.Fil: Aminahuel, Aimé. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones y Transferencia de Villa María. Universidad Nacional de Villa María. Centro de Investigaciones y Transferencia de Villa María; ArgentinaFil: Lapasini, Carina Paola. Universidad Nacional de Villa María. Instituto Académico Pedagógico de Ciencias Sociales; ArgentinaFil: Achilli, Carla. Universidad Nacional de Villa María. Instituto Académico Pedagógico de Ciencias Sociales; ArgentinaFil: Peiretti, Josefina. Universidad Nacional de Villa María. Instituto Académico Pedagógico de Ciencias Sociales; Argentin

Le Rôle de l'odontologiste médico-légal à la lumière de l'I.R.C.G.N. (De la théorie à la pratique)

L'IRCGN est le laboratoire de police scientifique de la Gendarmerie Nationale française qui contribue dans le cadre d'enquétes judiciaires, à la révélation des preuves scientifiques et notamment l'identification de personnes retrouvées décédées suite à une disparition, à un crime ou suite à une catastrophe de masse. L'identification de ces victimes est une nécessité morale, légale et administrative pour l'établissement de l'acte de décès. Le rôle de l'odontologiste médico-légal est primordial au sein de l'équipe pluridisciplinaire d'identification humaine avec pour mission de comparer les odontogrammes post-mortem et ante-mortem dans un but d'identification. Par l'examen de la denture, et à la demande des enquêteurs, il s'attache à préciser, entre autre, l'origine humaine, l'âge, le sexe et l'origine ethnique. Par l'étude d'un cas, nous illustrons dans quelle mesure, les données dentaires apportent des informations pertinentes lors d'une reconstruction faciale. Quelques exemples d'identification médico-légale sont détaillés dans ce mémoire de thèse afin de montrer d'une part, le travail de l'odontologiste médico-légal, et de préciser d'autre part les motivations dans le choix des techniques utilisées au sein de l'IRCGN.The IRCGN is the lorensic laboratory of the French National Gendarmerie contributing through judicial surveys, the revelation of scientific evidence including identification of persons found dead after a disappearance, a crime or after mass disaster. The identification 01 these victims is a moral, legal and administrative setting the death certificate. The role 01 the dentist is crucial lorensic within the multidisciplinary team 01 human identification with the mission to compare odontograms post-mortem and ante-mortem identification purposes. By examination of the teeth, and at the request of investigators, he endeavors to clarify, among other things, human origin, age, sex and ethnicity. Through a case study, we illustrate how the dental data provide relevant information on a facial reconstruction. Sorne examples of forensic identification are detailed in this thesis to show the one hand, the work of forensic dentistry, and specify other motivations in the choice of techniques used in the IRCGN.MONTPELLIER-BU Médecine UPM (341722108) / SudocMONTPELLIER-BU Odontologie (341722110) / SudocSudocFranceF

Data from: Adaptive value of phenological traits in stressful environments: predictions based on seed production and laboratory natural selection

Phenological traits often show variation within and among natural populations of annual plants. Nevertheless, the adaptive value of post-anthesis traits is seldom tested. In this study, we estimated the adaptive values of pre- and post-anthesis traits in two stressful environments (water stress and interspecific competition), using the selfing annual species Arabidopsis thaliana. By estimating seed production and by performing laboratory natural selection (LNS), we assessed the strength and nature (directional, disruptive and stabilizing) of selection acting on phenological traits in A. thaliana under the two tested stress conditions, each with four intensities. Both the type of stress and its intensity affected the strength and nature of selection, as did genetic constraints among phenological traits. Under water stress, both experimental approaches demonstrated directional selection for a shorter life cycle, although bolting time imposes a genetic constraint on the length of the interval between bolting and anthesis. Under interspecific competition, results from the two experimental approaches showed discrepancies. Estimation of seed production predicted directional selection toward early pre-anthesis traits and long post-anthesis periods. In contrast, the LNS approach suggested neutrality for all phenological traits. This study opens questions on adaptation in complex natural environment where many selective pressures act simultaneously