scholarly journals Food and fitness: associations between crop yields and life-history traits in a longitudinally monitored pre-industrial human population

2012 ◽  
Vol 279 (1745) ◽  
pp. 4165-4173 ◽  
Author(s):  
Adam D. Hayward ◽  
Jari Holopainen ◽  
Jenni E. Pettay ◽  
Virpi Lummaa
Keyword(s):  
Natural Selection ◽  
Crop Yields ◽  
Economic Status ◽  
Food Shortage ◽  
Human Populations ◽  
Fitness Traits ◽  
Animal Populations ◽  
Specific Mortality ◽  
Selection For ◽  
The Impact

Severe food shortage is associated with increased mortality and reduced reproductive success in contemporary and historical human populations. Studies of wild animal populations have shown that subtle variation in environmental conditions can influence patterns of mortality, fecundity and natural selection, but the fitness implications of such subtle variation on human populations are unclear. Here, we use longitudinal data on local grain production, births, marriages and mortality so as to assess the impact of crop yield variation on individual age-specific mortality and fecundity in two pre-industrial Finnish populations. Although crop yields and fitness traits showed profound year-to-year variation across the 70-year study period, associations between crop yields and mortality or fecundity were generally weak. However, post-reproductive individuals of both sexes, and individuals of lower socio-economic status experienced higher mortality when crop yields were low. This is the first longitudinal, individual-based study of the associations between environmental variation and fitness traits in pre-industrial humans, which emphasizes the importance of a portfolio of mechanisms for coping with low food availability in such populations. The results are consistent with evolutionary ecological predictions that natural selection for resilience to food shortage is likely to weaken with age and be most severe on those with the fewest resources.

Survival analyses

2021 ◽  
pp. 229-244
Author(s):  
Sarah Cubaynes ◽  
Simon Galas ◽  
Myriam Richaud ◽  
Ana Sanz Aguilar ◽  
Roger Pradel ◽  
...  
Keyword(s):  
Survival Data ◽  
Complex Life Cycle ◽  
Mortality Data ◽  
Human Populations ◽  
Imperfect Detection ◽  
Survival Analyses ◽  
Kaplan Meier ◽  
Animal Populations ◽  
Free Ranging ◽  
The Impact

Survival analyses are a key tool for demographers, ecologists, and evolutionary biologists. This chapter presents the most common methods and illustrates their use for species across the Tree of Life. It discusses the challenges associated with various types of survival data, how to model species with a complex life cycle, and includes the impact of environmental factors and individual heterogeneity. It covers the analysis of ‘known-fate’ data collected in lab conditions, using the Kaplan–Meier estimator and Cox’s proportional hazard regression analysis. Alternatively, survival data collected on free-ranging populations usually involve individuals missing at certain monitoring occasions and unknown time at death. The chapter provides an overview of capture–mark–recapture (CMR) models, from single-state to multi-state and multi-event models, and their use in animal and plant demography to estimate demographic parameters while correcting for imperfect detection of individuals. It discusses various inference frameworks available to implement CMR models using a frequentist or Bayesian approach. Only humans are an exception among free-ranging populations, with the existence of several consequent databases with perfect knowledge of age and cause of death for all individuals. The chapter presents an overview of the most common models used to describe mortality patterns over age and time using human mortality data. Throughout, focus is placed on eight case studies, which involve lab organisms, free-ranging animal populations, plant populations, and human populations. Each example includes data and codes, together with step-by-step guidance to run the survival analysis.

The impact of novel lyssavirus discovery

2017 ◽  
Vol 38 (1) ◽  
pp. 17 ◽  
Author(s):  
Ashley C Banyard ◽  
Anthony R Fooks
Keyword(s):  
Rabies Virus ◽  
Human Exposure ◽  
Animal Health ◽  
Potential Effect ◽  
Human Populations ◽  
Human Society ◽  
Scientific Interest ◽  
Animal Populations ◽  
Potential Impact ◽  
The Impact

The global discovery of novel lyssaviruses is of continued scientific interest through its importance to both public and animal health. Lyssaviruses cause an invariably fatal encephalitis that is more commonly known as rabies. The term rabies has a long history in human society, as rabies virus (RABV) is the only pathogen that is associated with 100% fatality once the onset of clinical disease has started. Although predominantly associated across the globe with domestic and feral dog populations, the association of bats is clear. Whilst evolutionarily associated with bats, RABV is most commonly transmitted to human populations through the bite of an infected dog and dogs are considered the primary reservoir of disease. Indeed, RABV does cause more than an estimated 70000 deaths every year globally in human populations and whilst this is largely in areas where the disease is endemic, areas that remain free of rabies must remain vigilant to the risk of re-incursion of disease. Characterisation of novel lyssaviruses is of importance on several levels. Not least to investigate the pathogenesis and potential transmission routes of different lyssavirus species but also to assess the potential effect of post-exposure treatments and vaccination should human exposure occur. Bat lyssaviruses and the problems associated with novel discoveries and the potential impact they have on both human and animal populations are discussed.

scholarly journals Computational and Functional Analysis of the Virus-Receptor Interface Reveals Host Range Trade-Offs in New World Arenaviruses

2015 ◽  
Vol 89 (22) ◽  
pp. 11643-11653 ◽  
Author(s):  
Scott A. Kerr ◽  
Eleisha L. Jackson ◽  
Oana I. Lungu ◽  
Austin G. Meyer ◽  
Ann Demogines ◽  
...  
Keyword(s):  
Natural Selection ◽  
New World ◽  
New Host ◽  
Virus Receptor ◽  
Computational Docking ◽  
Trade Offs ◽  
Animal Populations ◽  
Machupo Virus ◽  
Selection For ◽  
New Host Species

ABSTRACTAnimal viruses frequently cause zoonotic disease in humans. As these viruses are highly diverse, evaluating the threat that they pose remains a major challenge, and efficient approaches are needed to rapidly predict virus-host compatibility. Here, we develop a combined computational and experimental approach to assess the compatibility of New World arenaviruses, endemic in rodents, with the host TfR1 entry receptors of different potential new host species. Using signatures of positive selection, we identify a small motif on rodent TfR1 that conveys species specificity to the entry of viruses into cells. However, we show that mutations in this region affect the entry of each arenavirus differently. For example, a human single nucleotide polymorphism (SNP) in this region, L212V, makes human TfR1 a weaker receptor for one arenavirus, Machupo virus, but a stronger receptor for two other arenaviruses, Junin and Sabia viruses. Collectively, these findings set the stage for potential evolutionary trade-offs, where natural selection for resistance to one virus may make humans or rodents susceptible to other arenavirus species. Given the complexity of this host-virus interplay, we propose a computational method to predict these interactions, based on homology modeling and computational docking of the virus-receptor protein-protein interaction. We demonstrate the utility of this model for Machupo virus, for which a suitable cocrystal structural template exists. Our model effectively predicts whether the TfR1 receptors of different species will be functional receptors for Machupo virus entry. Approaches such at this could provide a first step toward computationally predicting the “host jumping” potential of a virus into a new host species.IMPORTANCEWe demonstrate how evolutionary trade-offs may exist in the dynamic evolutionary interplay between viruses and their hosts, where natural selection for resistance to one virus could make humans or rodents susceptible to other virus species. We present an algorithm that predicts which species have cell surface receptors that make them susceptible to Machupo virus, based on computational docking of protein structures. Few molecular models exist for predicting the risk of spillover of a particular animal virus into humans or new animal populations. Our results suggest that a combination of evolutionary analysis, structural modeling, and experimental verification may provide an efficient approach for screening and assessing the potential spillover risks of viruses circulating in animal populations.

scholarly journals Food production in an age of global warming and weirding

2018 ◽  
Vol 40 (4) ◽  
pp. 9-12
Author(s):  
Stuart Thompson
Keyword(s):  
Climate Change ◽  
Global Warming ◽  
Food Production ◽  
Crop Yields ◽  
Human Populations ◽  
Water Supplies ◽  
Competing Demands ◽  
Rainfall Patterns ◽  
The Impact ◽  
Do So

Some estimates suggest that we will need to double food production by 2050, and do so despite the effects of climate change on crop yields. The competing demands of agriculture and human populations upon water supplies can only become more extreme with time and are likely to be exacerbated by the impact of increased evaporation due to global warming and changes to rainfall patterns. Therefore, this article will examine some of the ways that we can produce food using less water.

scholarly journals The impact of natural selection on the evolution and function of placentally expressed galectins

2018 ◽  
Author(s):  
Zackery A. Ely ◽  
Jiyun M. Moon ◽  
Gregory R. Sliwoski ◽  
Amandeep K. Sangha ◽  
Xing-Xing Shen ◽  
...  
Keyword(s):  
Natural Selection ◽  
Protein Structure ◽  
Genomic Variation ◽  
Human Populations ◽  
Carbohydrate Binding ◽  
Sequence Evolution ◽  
Placental Development ◽  
Human Genetic Disease ◽  
3D Protein Structure ◽  
The Impact

AbstractImmunity genes have repeatedly experienced natural selection during mammalian evolution. Galectins are carbohydrate-binding proteins that regulate diverse immune responses, including maternal-fetal immune tolerance in placental pregnancy. Seven human galectins, four conserved across vertebrates and three specific to primates, are involved in placental development. To comprehensively study the molecular evolution of these galectins both across mammals and within humans, we conducted a series of between-and within-species evolutionary analyses. By examining patterns of sequence evolution between species, we found that primate-specific galectins showed uniformly high substitution rates, whereas two of the four other galectins experienced accelerated evolution in primates. By examining human population genomic variation, we found that galectin genes and variants, including variants previously linked to immune diseases, showed signatures of recent positive selection in specific human populations. By examining one nonsynonymous variant in Galectin-8 previously associated with autoimmune diseases, we further discovered that it is tightly linked to three other nonsynonymous variants; surprisingly, the global frequency of this four-variant haplotype is ∼50%. To begin understanding the impact of this major haplotype on Galectin-8 protein structure, we modeled its 3D protein structure and found that it differed substantially from the reference protein structure. These results suggest that placentally expressed galectins experienced both ancient and more recent selection in a lineage-and population-specific manner. Furthermore, our discovery that the major Galectin-8 haplotype is structurally distinct from and more commonly found than the reference haplotype illustrates the significance of understanding the evolutionary processes that sculpted variants associated with human genetic disease.

scholarly journals The Impact of Natural Selection on the Evolution and Function of Placentally Expressed Galectins

2019 ◽  
Vol 11 (9) ◽  
pp. 2574-2592 ◽  
Author(s):  
Zackery A Ely ◽  
Jiyun M Moon ◽  
Gregory R Sliwoski ◽  
Amandeep K Sangha ◽  
Xing-Xing Shen ◽  
...  
Keyword(s):  
Natural Selection ◽  
Protein Structure ◽  
Genomic Variation ◽  
Human Populations ◽  
Carbohydrate Binding ◽  
Sequence Evolution ◽  
Placental Development ◽  
Human Genetic Disease ◽  
3D Protein Structure ◽  
The Impact

Abstract Immunity genes have repeatedly experienced natural selection during mammalian evolution. Galectins are carbohydrate-binding proteins that regulate diverse immune responses, including maternal–fetal immune tolerance in placental pregnancy. Seven human galectins, four conserved across vertebrates and three specific to primates, are involved in placental development. To comprehensively study the molecular evolution of these galectins, both across mammals and within humans, we conducted a series of between- and within-species evolutionary analyses. By examining patterns of sequence evolution between species, we found that primate-specific galectins showed uniformly high substitution rates, whereas two of the four other galectins experienced accelerated evolution in primates. By examining human population genomic variation, we found that galectin genes and variants, including variants previously linked to immune diseases, showed signatures of recent positive selection in specific human populations. By examining one nonsynonymous variant in Galectin-8 previously associated with autoimmune diseases, we further discovered that it is tightly linked to three other nonsynonymous variants; surprisingly, the global frequency of this four-variant haplotype is ∼50%. To begin understanding the impact of this major haplotype on Galectin-8 protein structure, we modeled its 3D protein structure and found that it differed substantially from the reference protein structure. These results suggest that placentally expressed galectins experienced both ancient and more recent selection in a lineage- and population-specific manner. Furthermore, our discovery that the major Galectin-8 haplotype is structurally distinct from and more commonly found than the reference haplotype illustrates the significance of understanding the evolutionary processes that sculpted variants associated with human genetic disease.

scholarly journals Differences in local population history at the finest level: the case of the Estonian population

2020 ◽  
Vol 28 (11) ◽  
pp. 1580-1591 ◽  
Author(s):  
Vasili Pankratov ◽  
Francesco Montinaro ◽  
Alena Kushniarevich ◽  
Georgi Hudjashov ◽  
Flora Jay ◽  
...  
Keyword(s):  
Natural Selection ◽  
Genetic Structure ◽  
Population Size ◽  
Effective Population Size ◽  
Local Population ◽  
Population History ◽  
Human Populations ◽  
Effective Population ◽  
The Impact ◽  
Estonian Population

Abstract Several recent studies detected fine-scale genetic structure in human populations. Hence, groups conventionally treated as single populations harbour significant variation in terms of allele frequencies and patterns of haplotype sharing. It has been shown that these findings should be considered when performing studies of genetic associations and natural selection, especially when dealing with polygenic phenotypes. However, there is little understanding of the practical effects of such genetic structure on demography reconstructions and selection scans when focusing on recent population history. Here we tested the impact of population structure on such inferences using high-coverage (~30×) genome sequences of 2305 Estonians. We show that different regions of Estonia differ in both effective population size dynamics and signatures of natural selection. By analyzing identity-by-descent segments we also reveal that some Estonian regions exhibit evidence of a bottleneck 10–15 generations ago reflecting sequential episodes of wars, plague and famine, although this signal is virtually undetected when treating Estonia as a single population. Besides that, we provide a framework for relating effective population size estimated from genetic data to actual census size and validate it on the Estonian population. This approach may be widely used both to cross-check estimates based on historical sources as well as to get insight into times and/or regions with no other information available. Our results suggest that the history of human populations within the last few millennia can be highly region specific and cannot be properly studied without taking local genetic structure into account.

scholarly journals CAN CULLING TO PREVENT MONKEYPOX INFECTION BE COUNTER-PRODUCTIVE? SCENARIOS FROM A THEORETICAL MODEL

2012 ◽  
Vol 20 (03) ◽  
pp. 259-283 ◽  
Author(s):  
JEAN M. TCHUENCHE ◽  
CHRIS T. BAUCH
Keyword(s):  
Control Strategies ◽  
Theoretical Models ◽  
Transmission Model ◽  
Human Populations ◽  
Contact Rate ◽  
Disease Dynamics ◽  
Human Contact ◽  
Animal Populations ◽  
The Impact ◽  
Animal Reservoirs

In the last two decades, monkeypox outbreaks in human populations in Africa and North America have reminded us that smallpox is not the only poxvirus with potential to cause harm in human populations. Monkeypox transmission is sustained in animal reservoirs, and animal–human contacts are responsible for sporadic outbreaks in humans. Here, we develop and analyze a deterministic epizootic (animal-based) transmission model capturing disease dynamics in an animal population, disease dynamics in an age-structured human population, and their coupling through animal–human contacts. We develop a single-patch model as well as a two-patch meta-population extension. We derive mathematical expressions for the basic reproduction number, which governs the likelihood of a large outbreak. We also investigate the effectiveness of culling strategies and the impact of changes in the animal–human contact rate. Numerical analysis of the model suggests that, for some parameter values, culling can actually have the counter-productive outcome of increasing monkeypox infection in children, if animal reproduction is a density-dependent process. The likelihood of this happening, as well as the prevalence of monkeypox in humans, depends sensitively on the animal–human contact rate. We also find that ignoring age structure in human populations can lead to overestimating the transmissibility of monkeypox in humans. The effectiveness of monkeypox control strategies such as culling can strongly depend on the details of demography and epidemiology in the animal reservoirs that sustain it. Therefore, to better understand how to prevent and control monkeypox outbreaks in humans, better empirical data from wild animal populations where monkeypox is endemic must be collected, and these data must be incorporated into highly structured theoretical models.

HOW CLIMATE CHANGE CAN INFLUENCE THE AGRICULTURE IN UKRAINE: A REVIEW

2020 ◽  
Author(s):  
N. Maidanovych ◽  
Keyword(s):  
Climate Change ◽  
Crop Yields ◽  
Soil Surface ◽  
Winter Period ◽  
Negative Consequences ◽  
Resource Saving ◽  
Impact Of Climate Change ◽  
Positive Effects ◽  
Average Annual Temperature ◽  
The Impact

The purpose of this work is to review and analyze the main results of modern research on the impact of climate change on the agro-sphere of Ukraine. Results. Analysis of research has shown that the effects of climate change on the agro-sphere are already being felt today and will continue in the future. The observed climate changes in recent decades have already significantly affected the shift in the northern direction of all agro-climatic zones of Europe, including Ukraine. From the point of view of productivity of the agro-sphere of Ukraine, climate change will have both positive and negative consequences. The positives include: improving the conditions of formation and reducing the harvesting time of crop yields; the possibility of effective introduction of late varieties (hybrids), which require more thermal resources; improving the conditions for overwintering crops; increase the efficiency of fertilizer application. Model estimates of the impact of climate change on wheat yields in Ukraine mainly indicate the positive effects of global warming on yields in the medium term, but with an increase in the average annual temperature by 2 ° C above normal, grain yields are expected to decrease. The negative consequences of the impact of climate change on the agrosphere include: increased drought during the growing season; acceleration of humus decomposition in soils; deterioration of soil moisture in the southern regions; deterioration of grain quality and failure to ensure full vernalization of grain; increase in the number of pests, the spread of pathogens of plants and weeds due to favorable conditions for their overwintering; increase in wind and water erosion of the soil caused by an increase in droughts and extreme rainfall; increasing risks of freezing of winter crops due to lack of stable snow cover. Conclusions. Resource-saving agricultural technologies are of particular importance in the context of climate change. They include technologies such as no-till, strip-till, ridge-till, which make it possible to partially store and accumulate mulch on the soil surface, reduce the speed of the surface layer of air and contribute to better preservation of moisture accumulated during the autumn-winter period. And in determining the most effective ways and mechanisms to reduce weather risks for Ukrainian farmers, it is necessary to take into account the world practice of climate-smart technologies.

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