Human Demography Research Articles

Morphological human bone features and demography controlling damage accumulation and fracture: a finite element study

Prediction of bone fracture risk is clinically challenging. Computational modeling plays a vital role in understanding bone structure and diagnosing bone diseases, leading to novel therapies. The research objectives were to demonstrate the anisotropic structure of the bone at the micro-level taking into consideration the density and subject demography, such as age, gender, body mass index (BMI), height, weight, and their roles in damage accumulation. Out of 438 developed 3D bone models at the micro-level, 46.12% were female. The age distribution ranged from 23 to 95 years. The research unfolds in two phases: micro-morphological features examination and stress distribution investigation. Models were developed using Mimics 22.0 and SolidWorks. The anisotropic material properties were defined before importing into Ansys for simulation. Computational simulations further uncovered variations in maximum von-Misses stress, highlighting that young Black males experienced the highest stress at 127.852 ± 10.035 MPa, while elderly Caucasian females exhibited the least stress at 97.224 ± 14.504 MPa. Furthermore, age-related variations in stress levels for both normal and osteoporotic bone micro models were elucidated, emphasizing the intricate interplay of demographic factors in bone biomechanics. Additionally, a prediction equation for bone density incorporating demographic variables was proposed, offering a personalized modeling approach. In general, this study, which carefully examines the complexities of how bones behave at the micro-level, emphasizes the need for an enhanced approach in orthopedics. We suggest taking individual characteristics into account to make therapeutic interventions more precise and effective.

DORA: an interactive map for the visualization and analysis of ancient human DNA and associated data.

The ability to sequence ancient genomes has revolutionized the way we study evolutionary history by providing access to the most important aspect of evolution-time. Until recently, studying human demography, ecology, biology, and history using population genomic inference relied on contemporary genomic datasets. Over the past decade, the availability of human ancient DNA (aDNA) has increased rapidly, almost doubling every year, opening the way for spatiotemporal studies of ancient human populations. However, the multidimensionality of aDNA, with genotypes having temporal, spatial and genomic coordinates, and integrating multiple sources of data, poses a challenge for developing meta-analyses pipelines. To address this challenge, we developed a publicly-available interactive tool, DORA, which integrates multiple data types, genomic and non-genomic, in a unified interface. This web-based tool enables browsing sample metadata alongside additional layers of information, such as population structure, climatic data, and unpublished samples. Users can perform analyses on genotypes of these samples, or export sample subsets for external analyses. DORA integrates analyses and visualizations in a single intuitive interface, resolving the technical issues of combining datasets from different sources and formats, and allowing researchers to focus on the scientific questions that can be addressed through analysis of aDNA datasets.

Conditional frequency spectra as a tool for studying selection on complex traits in biobanks.

Natural selection on complex traits is difficult to study in part due to the ascertainment inherent to genome-wide association studies (GWAS). The power to detect a trait-associated variant in GWAS is a function of frequency and effect size - but for traits under selection, the effect size of a variant determines the strength of selection against it, constraining its frequency. To account for GWAS ascertainment, we propose studying the joint distribution of allele frequencies across populations, conditional on the frequencies in the GWAS cohort. Before considering these conditional frequency spectra, we first characterized the impact of selection and non-equilibrium demography on allele frequency dynamics forwards and backwards in time. We then used these results to understand conditional frequency spectra under realistic human demography. Finally, we investigated empirical conditional frequency spectra for GWAS variants associated with 106 complex traits, finding compelling evidence for either stabilizing or purifying selection. Our results provide insight into polygenic score portability and other properties of variants ascertained with GWAS, highlighting the utility of conditional frequency spectra.

Urban trees as a lever for citizen engagement in public consultation processes: the case of Paris, France.

In the present context of increasing human population demography, worldwide social crises, and rapid ecological global change, large cities are facing major socio-environmental challenges. This convokes authorities to adapt their governance and urban planning to reconcile urban development, ecological systems, and city dwellers in the most sustainable way. To achieve such goals, local officials have to associate all local actors, including city-dwellers, to the decision-making process through participatory governance and/or participatory systems. Here, we elaborated an original pilot project governance system for a "Participatory System Combining Town Planning and Science" (the 2PS-CiTy), as part of the revision of the Local Urban Plan (LUP) of Paris, France, into a Bioclimatic LUP held from 2020 to 2024. By implementing 2PS-CiTy, we aimed to answer "How to turn trees into a lever for inhabitants' engagement in urban consultation systems?" Trees were chosen because they are emblematic elements of nature with significant roles in ecosystemic services such as urban climate regulation. Parisians were invited to (i) share in the first questionnaire some information on their knowledge about the LUP and their engagement in it, (ii) identify urban trees they consider remarkable, (iii) explain their choice in a second questionnaire, (iv) contribute to the urban consultation as part of the LUP revision, and finally, (v) give their feedback during a dedicated survey. Out of the 41 Parisians who took part in 2PS-City, 83% declared they were motivated to participate because they could contribute to the tree census, which in turn can constructively contribute to the Parisian LUP revision to bring more nature and sustainability in town. This study demonstrates that trees can be used as a lever for inhabitants' engagement in urban consultation systems to make cities more sustainable. Our survey also showed that the 2PS-CiTy governance system could be improved by (1) developing a participatory culture among decision-makers and (2) preventing nowadays silo governance from developing the most promising public governance systems that involve the departments of green space, urban planning, and local democracy.

Characterizing personalized ecologies

AbstractPeople have unique sets of direct sensory interactions with wild species, which change through their days, weeks, seasons, and lifetimes. Despite having important influences on their health and well‐being and their attitudes towards nature, these personalized ecologies remain surprisingly little studied and are poorly understood. However, much can be inferred about personalized ecologies by considering them from first principles (largely macroecological), alongside insights from research into the design and effectiveness of biodiversity monitoring programmes, knowledge of how animals respond to people, and studies of human biology and demography. Here I first review how three major sets of drivers, opportunity, capability and motivation, shape people's personalized ecologies. Second, I then explore the implications of these mechanisms for how more passively and more actively practical improvements can be made in people's personalized ecologies. Particularly in light of the declines in the richness of these ecologies that are being experienced in much of the world (the so‐called ‘extinction of experience’), and the significant consequences, marked improvement in many people's interactions and experiences with nature may be key to the future of biodiversity.

Informing climate-health adaptation options through mapping the needs and potential for integrated climate-driven early warning forecasting systems in South Asia-A scoping review.

Climate change is widely recognised to threaten human health, wellbeing and livelihoods, including through its effects on the emergence, spread and burdens of climate-and water-sensitive infectious diseases. However, the scale and mechanisms of the impacts are uncertain and it is unclear whether existing forecasting capacities will foster successful local-level adaptation planning, particularly in climate vulnerable regions in developing countries. The purpose of this scoping review was to characterise and map priority climate- and water-sensitive diseases, map existing forecasting and surveillance systems in climate and health sectors and scope out the needs and potential to develop integrated climate-driven early warning forecasting systems for long-term adaptation planning and interventions in the south Asia region. We searched Web of Science Core Collection, Scopus and PubMed using title, abstract and keywords only for papers focussing on climate-and water-sensitive diseases and explicit mention of either forecasting or surveillance systems in south Asia. We conducted further internet search of relevant national climate adaptation plans and health policies affecting disease management. We identified 187 studies reporting on climate-sensitive diseases and information systems in the south Asia context published between 1992 and 2024. We found very few robust, evidenced-based forecasting systems for climate- and water- sensitive infectious diseases, which suggests limited operationalisation of decision-support tools that could inform actions to reduce disease burdens in the region. Many of the information systems platforms identified focussed on climate-sensitive vector-borne disease systems, with limited tools for water-sensitive diseases. This reveals an opportunity to develop tools for these neglected disease groups. Of the 34 operational platforms identified across the focal countries, only 13 (representing 38.2%) are freely available online and all were developed and implemented by the human health sector. Tools are needed for other south Asian countries (Afghanistan, Sri Lanka, Bhutan) where the risks of infectious diseases are predicted to increase substantially due to climate change, drought and shifts in human demography and use of ecosystems. Altogether, the findings highlight clear opportunities to invest in the co-development and implementation of contextually relevant climate-driven early warning tools and research priorities for disease control and adaptation planning.

The use of GNSS technology in smartphones to collect sensitive data on human mobility practices: Ethical challenges and potential solutions.

The advent of mobile smartphones and similar technology has opened new opportunities for studying human mobility within psychology and companion disciplines such as human geography, demography, and sociology. This article examines how such research raises novel ethical concerns. To do so, we outline two research projects: one based in Northern Ireland (The Belfast Mobility Project) and the other in Chile (The Norm-Contact Mobility Project), drawing concrete examples of the ethical challenges encountered throughout both projects, which used global navigational satellite systems as a tool for data collection. We discuss new threats to participant confidentiality and anonymity, problems of "unanticipated" data collection and exploitation, emerging difficulties in achieving properly informed consent, and concerns regarding the representation of vulnerable populations with limited access to smartphones and a legitimate fear of surveillance. We also reflect on the different measures we took to tackle these challenges and discuss the importance of implementing wider changes in the protocols associated with basic ethical research principles. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Human settlement density, not late Holocene climate change, influenced Artiodactyla species abundance in northeastern California faunal assemblages

Variation in late Holocene artiodactyl (e.g., deer, pronghorn, bighorn sheep) hunting in northern California has often been examined from a behavioral ecological perspective to understand past foraging and land-use practices and related changes in human behavior, including settlement patterns, technological change, social signaling, large-scale resource intensification, and anthropogenic resource depression. However, rarely are past climate records and proxies of human population density coupled with zooarchaeological estimates of artiodactyl abundance to evaluate the ecological and anthropogenic drivers of changes in species representation over time. To better understand changes in human behavior related to past large game hunting, we disentangle the causal relationships between late Holocene climate change, human demography, and artiodactyl abundance to assess whether climate change, human hunting, or both impacted the abundance of artiodactyls in zooarchaeological assemblages from northeastern California. We evaluate how climatic variability and inferred human settlement density impacted artiodactyl abundance using modeled paleoclimatic reconstructions, distributions of radiocarbon dates, and faunal data derived from 35 archaeological sites and 37,319 individual faunal specimens. Using piecewise structural equation models, we assess the direct and mediating effects between climate, human settlement density, and artiodactyl abundance and determine the individual effects of these variables on large game species representation in zooarchaeological assemblages. We find that expanding human settlement density and related increases in logistical foraging—not late Holocene climate change—directly impacts the relative abundance of artiodactyls in these assemblages. Moreover, our findings reveal that the effects of climate change are entirely mediated through human settlement density. While our study is unable to decipher if observed changes in human behavior were motivated by goals related to energetic maximization or costly signaling, our study does provide a useful framework for separating the effects of human- and climate-induced explanations for variation in species composition in faunal assemblages.

Mapping the literature on Gen Z purchasing behavior: A bibliometric analysis using VOSviewer

Generation Z makes up the largest proportion of the world’s population and owns active spending power. Born in the internet information age, they have diverse values and consumer behaviors compared to other cohorts of generations. While there has been a significant increase in research on the purchasing behavior of Generation Z in recent years, there are particularly few bibliometric studies in this field. This study aims to sort out the current research status on the purchasing behavior of Generation Z, identify the evolution of purchasing behavior research of Generation Z, determine key research hotspots, and explore future research directions and priority suggestions by analyzing the current literature. The bibliometric analysis is based on the citation information of 638 literature items about Generation Z purchasing behavior in the Scopus database. The results sort out the knowledge structure of the purchasing behavior domain of Generation Z and draw a visual map of the network. Four popular research themes are identified based on keyword co-occurrence analysis, namely the influencing factors of Generation Z consumption behavior, the comparative study with other generations of consumers, the analysis from the perspective of human demography, and the study of sustainable consumption behavior. Studies on Generation Z consumers’ spending habits from 2001 to 2022 may be divided into three stages related to the growth process of Generation Z. Future research should focus on the influence of social media on the purchasing behavior of Generation Z and the sustainability of their consumption patterns.

Pathways for socio-economic system transitions expressed as a Markov chain.

Cross-impact balance (CIB) analysis provides a system-theoretical view of scenarios useful for investigating complex socio-economic systems. CIB can synthesize a variety of qualitative or quantitative inputs and return information suggestive of system evolution. Current software tools for CIB are limited to identifying system attractors as well as describing system evolution from only one scenario of initial conditions at a time. Through this study, we enhance CIB by developing and applying a method that considers all possible system evolutions as transitions in a Markov chain. We investigated a simple three-variable system (27 possible scenarios) of the demographic transition and were able to generally replicate the findings of traditional CIB. Through our experiments with four possible approaches to produce CIB Markov chains, we found that information about transition pathways is gained; however, information about system attractors may be lost. Through a comparison of model results to a recent literature review on human demography, we found that low-income countries are more likely to remain stuck in a demographic trap if economic development is not prioritized alongside educational gains. Future work could test our comparative methodological findings for systems comprised of more than three variables.

Epidemiological connectivity between humans and animals across an urban landscape.

Urbanization is predicted to be a key driver of disease emergence through human exposure to novel, animal-borne pathogens. However, while we suspect that urban landscapes are primed to expose people to novel animal-borne diseases, evidence for the mechanisms by which this occurs is lacking. To address this, we studied how bacterial genes are shared between wild animals, livestock, and humans (n = 1,428) across Nairobi, Kenya-one of the world's most rapidly developing cities. Applying a multilayer network framework, we show that low biodiversity (of both natural habitat and vertebrate wildlife communities), coupled with livestock management practices and more densely populated urban environments, promotes sharing of Escherichia coli-borne bacterial mobile genetic elements between animals and humans. These results provide empirical support for hypotheses linking resource provision, the biological simplification of urban landscapes, and human and livestock demography to urban dynamics of cross-species pathogen transmission at a landscape scale. Urban areas where high densities of people and livestock live in close association with synanthropes (species such as rodents that are more competent reservoirs for zoonotic pathogens) should be prioritized for disease surveillance and control.

Climate-driven habitat shifts of high-ranked prey species structure Late Upper Paleolithic hunting

Changing climates in the past affected both human and faunal population distributions, thereby structuring human diets, demography, and cultural evolution. Yet, separating the effects of climate-driven and human-induced changes in prey species abundances remains challenging, particularly during the Late Upper Paleolithic, a period marked by rapid climate change and marked ecosystem transformation. To disentangle the effects of climate and hunter-gatherer populations on animal prey species during the period, we synthesize disparate paleoclimate records, zooarchaeological data, and archaeological data using ecological methods and theory to test to what extent climate and anthropogenic impacts drove broad changes in human subsistence observed in the Late Upper Paleolithic zooarchaeological records. We find that the observed changes in faunal assemblages during the European Late Upper Paleolithic are consistent with climate-driven animal habitat shifts impacting the natural abundances of high-ranked prey species on the landscape rather than human-induced resource depression. The study has important implications for understanding how past climate change impacted and structured the diet and demography of human populations and can serve as a baseline for considerations of resilience and adaptation in the present.

Prehistoric human migration between Sundaland and South Asia was driven by sea-level rise

Rapid sea-level rise between the Last Glacial Maximum (LGM) and the mid-Holocene transformed the Southeast Asian coastal landscape, but the impact on human demography remains unclear. Here, we create a paleogeographic map, focusing on sea-level changes during the period spanning the LGM to the present-day and infer the human population history in Southeast and South Asia using 763 high-coverage whole-genome sequencing datasets from 59 ethnic groups. We show that sea-level rise, in particular meltwater pulses 1 A (MWP1A, ~14,500–14,000 years ago) and 1B (MWP1B, ~11,500–11,000 years ago), reduced land area by over 50% since the LGM, resulting in segregation of local human populations. Following periods of rapid sea-level rises, population pressure drove the migration of Malaysian Negritos into South Asia. Integrated paleogeographic and population genomic analysis demonstrates the earliest documented instance of forced human migration driven by sea-level rise.

Biocultural perspectives of infectious diseases and demographic evolution: Tuberculosis and its comorbidities through history.

Anthropologists recognize the importance of conceptualizing health in the context of the mutually evolving nature of biology and culture through the biocultural approach, but biocultural anthropological perspectives of infectious diseases and their impacts on humans (and vice versa) through time are relatively underrepresented. Tuberculosis (TB) has been a constant companion of humans for thousands of years and has heavily influenced population health in almost every phase of cultural and demographic evolution. TB in human populations has been dramatically influenced by behavior, demographic and epidemiological shifts, and other comorbidities through history. This paper critically discusses TB and some of its major comorbidities through history within a biocultural framework to show how transitions in human demography and culture affected the disease-scape of TB. In doing so, I address the potential synthesis of biocultural and epidemiological transition theory to better comprehend the mutual evolution of infectious diseases and humans.

Modelling the West Nile virus force of infection in the European human population

West Nile virus (WNV) is among the most recent emerging mosquito-borne pathogens in Europe where each year hundreds of human cases are recorded. We developed a relatively simple technique to model the WNV force of infection (FOI) in the human population to assess its dependence on environmental and human demographic factors. To this aim, we collated WNV human case-based data reported to the European Surveillance System from 15 European Countries during the period 2010–2021. We modelled the regional WNV FOI for each year through normal distributions and calibrated the constituent parameters, namely average (peak timing), variance and overall intensity, to observed cases. Finally, we investigated through regression models how these parameters are associated to a set of climatic, environmental and human demographic covariates. Our modelling approach shows good agreement between expected and observed epidemiological curves. We found that FOI magnitude is positively associated with spring temperature and larger in more anthropogenic semi-natural areas, while FOI peak timing is negatively related to summer temperature. Unsurprisingly, FOI is estimated to be greater in regions with a larger fraction of elderly people, who are more likely to contract severe infections. Our results confirm that temperature plays a key role in shaping WNV transmission in Europe and provide some interesting hints on how human presence and demography might affect WNV burden. This simple yet reliable approach could be easily adopted for early warning and to address epidemiological investigations of other vector-borne diseases, especially where eco-epidemiological data are scarce.

The loss of biodiversity in Madagascar is contemporaneous with major demographic events

Only 400km off the coast of East Africa, the island of Madagascar is one of the last large land masses to have been colonized by humans. While many questions surround the human occupation of Madagascar, recent studies raise the question of human impact on endemic biodiversity and landscape transformation. Previous genetic and linguistic analyses have shown that the Malagasy population has emerged from an admixture that happened during the last millennium, between Bantu-speaking African populations and Austronesian-speaking Asian populations. By studying the sharing of chromosome segments between individuals (IBD determination), local ancestry information, and simulated genetic data, we inferred that the Malagasy ancestral Asian population was isolated for more than 1,000 years with an effective size of just a few hundred individuals. This isolation ended around 1,000 years before present (BP) by admixture with a small African population. Around the admixture time, there was a rapid demographic expansion due to intrinsic population growth of the newly admixed population, which coincides with extensive changes in Madagascar's landscape and the extinction of all endemic large-bodied vertebrates. Therefore, our approach can provide new insights into past human demography and associated impacts on ecosystems.

Developing a Geocultural Database of Quaternary Palaeoenvironmental Sites and Archaeological Sites in Southeast Arabia: Inventory, Endangerment Assessment, and a Roadmap for Conservation

Quaternary palaeoenvironmental (QP) sites in Southeast Arabia are important not only to understand the history of global climate change but also to study how ancient humans adapted to a changing natural environment. These sites, however, are currently missing from conservation frameworks despite reports of destroyed sites and sites under imminent threat. This study presents the Geocultural Database of Southeast Arabia, the first open-access database on QP sites in this region, created as a comprehensive inventory of regional QP sites and a tool to analyse QP records and archaeological records. The endangerment assessment of QP sites in this database reveals that 13% of QP sites have already been destroyed and 15% of them are under imminent threat of destruction, primarily due to urban development and infrastructure development. Chronological and spatial analyses of QP and archaeological sites and records highlight the intricate relationship between palaeoenvironment and archaeology and emphasise the need for sub-regional-scale studies to understand the variation of climatic conditions within the region, especially to study changes in the ancient human demography. This database illustrates the potential of a geocultural approach that combines archaeological heritage with Quaternary geoheritage as a way forward for the conservation of QP sites at risk.

ARCHAEOGENETICS AND HEALTH GEOGRAPHY OF DISEASE IN ASSESSING THE EFFECTS OF PANDEMICS

Recent outbreaks of various deadliest diseases provide a histrionic example of the destruction and dread of epidemics, especially those brought on by newly discovered or remerging diseases. Most research on epidemic diseases is dominated by a focus on managing and preventing infections in living populations. Therefore, a systematic study is critically needed to mitigate the risk and impacts of pandemics before it hits globally in an unprecedented manner. In this regard, the historical study of epidemics, alongside the investigation of the health geography, adds temporal depth to our understanding of the causes and effects of diseases essential for making future predictions about how diseases may affect human biology and demography. This review summarizes some of the advancements in our knowledge of the genetic foundations of diseases, recent human changes, and long evolutionary history that can all contribute to understanding how and why people become vulnerable to epidemics. Analyzing the recent COVID-19 pandemic and Cancer data in this review, it has become evident that evolutionary genetics gradually increase our understanding of geographies of disease by combining the knowledge with the evolutionary history recorded in the human genomes. The increasing availability of diverse genetic information from different populations will help us define an individual's disease risk more precisely in the future.

Climate change, migrations, and the peopling of sine-Saloum mangroves (Senegal) in the past 6000 years

We present a reconstruction of human demography and shell fishing activity in the Sine-Saloum mangrove Delta (Senegal) in the past 6000 years using the summed probability density (SPD) of radiocarbon dates in archaeological shell middens. We explore how this local history relates to the climatic and political history of West Africa. We find that traces of human presence were scarce from 6000 to 2000 yr BP, partly because the geomorphology of the estuary was less favorable to human settlements at that time. A specialized shell fishing population migrated massively to the Sine-Saloum around 2000 yr BP, at the end of the aridification trend that followed the African humid period. This population, likely coming from the northern coast in search of land and resources, fleeing from aridity and the subsequent warfare, found refuge in the coastal mangroves and reached a maximum activity at about 1700 yr BP. This period corresponds to the beginning of trans-Saharan trade, and to a political complexification that would give rise to the Ghana empire. The incoming migration may have occurred in two waves as suggested by two peaks in the SPD curve at 200–400 CE and 600–800 CE and by cultural differences within the Delta. Most sites in the Sine-Saloum islands were abandoned in the early 15th century, before the arrival of Europeans, possibly because intensive shell fishing was not sustainable anymore, or because of the regional political destabilization associated to the fall of the Ghana empire and the beginning of the Mali empire. Shortly after, in agreement with oral traditions, a new population lead by the Manding Guelwars, moved to the Sine Saloum after a military defeat and founded the modern towns. They had a reduced shellfishing activity compared to previous inhabitants, possibly because activities were more oriented to the new trade with Europeans or to a prosperous agriculture in more humid climatic conditions that prevailed from 1500 to 1800 CE.

Human density and sampling time explain richness of anurans in the brazilian biomes

Anuran richness patterns are strongly influenced by environmental factors. However, investigations on this issue have focused on the influence of abiotic factors without considering the joint effect of many existing variables, including the data sampling methodology and human demography. In this study we investigated the relationship between 21 environmental variables and anuran richness in brazilian biomes. Environmental variables represent a combination of human demographics, topographic, climatic and vegetation characteristics, and data sampling methodologies. We used principal component factorization and regressive and autoregressive models to select the most relevant variables for explaining anuran richness. Richness was correlated with demographic density, vegetation, accumulated rainfall, accumulated rainfall in the third and fourth quarter of the year, and accumulated rainfall in the first and second half of the year. However, the regressive and autoregressive models showed that human demographic density, sampling time, and sampling methodology were the best predictors of anuran richness. Our results highlight the importance of considering the effects of the human footprint and the methodology used for data collection on anuran species richness.