Demographic History Research Articles

Cultural-Environmental Systems and the Archaeology of Climate Change and Social Complexity: Midwest and Southeast United States

The investigation of dynamic fully integrated cultural-environmental systems is one grand challenge facing archaeologists in this century. In the Midwest and Southeast United States, archaeologists recently increased their study of Mississippian social systems (ca. AD 1000–1600) in relationship to paleoclimate and paleoenvironmental data. Significant differences in chronological control between archaeological chronologies and paleoenvironmental records pose challenges to the study of cultural-environmental systems in this region and often result in equifinal results. Three major lines of paleoenvironmental records are reviewed: bald cypress tree-ring records, the Living Blended Drought Atlas (LBDA), and lake-bottom sediment cores. The strongest approaches include local and regional multiproxy environmental records from the same location as a well-investigated archaeological site(s) or region(s). In the rare case where the cores also encode a regional population history, it may be possible to develop stronger inferences that consider variation within and between communities and their vulnerability to climate change and environmental catastrophes.

Genetic diversity and structure of Persicaria amphibia (Polygonaceae) in South Korea using genotyping by sequencing.

Persicaria amphibia, a member of the Polygonaceae family, exists both aquatic and terrestrial forms. It is native to North America, Asia, Europe, and some parts of Africa. This study aimed to determine the genetic diversity within and among populations of P. amphibia and the distribution characteristics of each population to investigate insights into the genetic structure and conservation of P. amphibia. In this study, the genetic diversity and structure of 84 P. amphibia individuals from 7 populations in South Korea were analyzed using genotyping-by-sequencing (GBS). We used 2,469 single nucleotide polymorphisms (SNPs) to analyze genetic diversity, principal components, structure, and phylogeny. Our results showed a mean observed heterozygosity and mean expected heterozygosity of 0.34409 and 0.34082, respectively. Genetic diversity analysis indicated that the variation among populations (60.08%) was greater than that within populations (39.92%). Fixation index values, principal components analysis, structure, and phylogeny analyses showed that the population in Gyodongdo, Ganghwa Island was highly different. These results provide important insights for better understand the population history and genetic structure of P. amphibia.

Admixture With Cultivated Sunflower Likely Facilitated Establishment and Spread of Wild Sunflower (Helianthus annuus) in Argentina.

A better understanding of the genetic and ecological factors underlying successful invasions is critical to mitigate the negative impacts of invasive species. Here, we study the invasion history of Helianthus annuus populations from Argentina, with particular emphasis on the role of post-introduction admixture with cultivated sunflower (also H. annuus) and climate adaptation driven by large haploblocks. We conducted genotyping-by-sequencing of samples of wild populations as well as Argentinian cultivars and compared them with wild (including related annual Helianthus species) and cultivated samples from the native range. We also characterised samples for 11 known haploblocks associated with environmental variation in native populations to test whether haploblocks contributed to invasion success. Population genomics analyses supported two independent geographic sources for Argentinian populations, the central United States and Texas, but no significant contribution of related annual Helianthus species. We found pervasive admixture with cultivated sunflower, likely as result of post-introduction hybridization. Genomic scans between invasive populations and their native sources identified multiple genomic regions of divergence, possibly indicative of selection, in the invaded range. These regions significantly overlapped between the two native-invasive comparisons and showed disproportionally high crop ancestry, suggesting that crop alleles contributed to invasion success. We did not find evidence of climate adaptation mediated by haploblocks, yet outliers of genome scans were enriched in haploblock regions and, for at least two haploblocks, the cultivar haplotype was favoured in Argentina. Our results show that admixture with cultivated sunflower played a major role in the establishment and spread of H. annuus populations in Argentina.

The role of parental consanguinity and familial aggregation in development of multiple sclerosis: a case–control study

BackgroundSeveral studies pointed out the importance of genetic risk factors such as parental consanguinity (PC) and familial multiple sclerosis (FMS) in the risk of MS. This study aimed to investigate the PC and FMS among people with MS (pwMS) in Isfahan, Iran.MethodsThis case–control study was conducted on pwMS from the MS clinic of Kashani Hospital, Isfahan, Iran, in October 2023. A group of healthy controls (HC) were also recruited. Data on demographic and clinical characteristics and history of PC and FMS were collected from participants. The relationships between PC, FMS, and developing MS were assessed using multinomial logistic regression analysis. The odds ratio (OR) with a 95% confidence interval (CI) was computed.ResultsA total number of 4264 pwMS and 400 HCs were included. The prevalence of PC and FMS among pwMS were 29.3% and 24%, respectively. Multinomial logistic regression adjusted for age and sex indicated that the odds of developing MS were significantly associated with a history of PC (OR = 3.03, 95% CI 2.23 to 4.13, p < 0.001) and FMS (OR = 5.42, 95% CI 3.51 to 8.38, p < 0.001).ConclusionPC and FMS can increase the risk of developing MS. They should be considered along with other risk factors for developing MS. A comprehensive conclusion requires further research.

A Pleistocene Biogeography in Miniature: The Small‐Scale Evolutionary History of Podarcis lusitanicus (Squamata, Lacertidae)

ABSTRACTAimRecent literature is unveiling more complex responses of biodiversity to Pleistocenic climatic oscillations than those derived from initial models based solely on southern glacial macrorefugia. Here, we zoom in to delve into the genetic diversity and population structure of Podarcis lusitanicus, a lizard species native to the north‐western Iberian Peninsula.LocationNorth‐western Iberian Peninsula.TaxonPodarcis lusitanicus.MethodsUtilising a comprehensive multilocus approach, we explored the species' phylogeography and demographic history at a very fine spatial scale and timeframe. Concurrently, we evaluated both current and historical habitat suitability for the species, linking it to the observed demographic trends. We examined DNA sequences from two mitochondrial (cytb and ND4) and three nuclear genes (ACM4, MC1R and PDC) in 230 specimens collected from 21 populations spanning most of the species' distribution range.ResultsOur findings corroborate cytonuclear discordances in Podarcis, with nuclear genes failing to identify the mitochondrial clades in P. lusitanicus. Despite its separation from other Podarcis species approximately 4 million years ago, its diversification occurred much more recently, around 0.4 million years ago, resulting in three monophyletic lineages that are geographically coherent. This pattern suggests that some lineages of P. lusitanicus might have gone extinct after the split from the common ancestor. Pleistocene climatic oscillations profoundly influenced the demographic history of the species. During warmer periods, such as the Last Interglacial, populations expanded and came into secondary contact, whereas during the Last Glacial Maximum, populations contracted and became isolated in multiple micro‐refugia. The subsequent Mid‐Holocene warming facilitated population recovery, range expansion and lineage admixture.Main ConclusionsThis study underscores the intricate interplay between isolation and dispersal at a microscale, driven by Pleistocene climatic fluctuations, which have profoundly shaped the genetic structure and diversity of Iberian terrestrial biodiversity and may remain overlooked by biogeographic studies at coarser scales.

Adopting Covid-19 and Flu Testing Strategies In An Underserved Community

Abstract Introduction/Objective The COVID-19 pandemic has had a significant impact on communities worldwide, while little is known about how medically underserved minority communities perceive and experience COVID-19 and/or COVID- 19/Flu combined testing. This research target at a medically underserved community in east Harris County, Texas, and was designed to 1) understand the perception of the single COVID-19 test as well as the COVID-19 and flu combined test, 2) implement different testing strategies in collaboration with the local community. Methods/Case Report Residents in the eligible communities who are age ≥ 18 years or older are recruited through community engagement groups and community originations. Participant’s demographic information, perception and histories of vaccination and testing were collected through a cross-sectional questionnaire. Participants willing to undergo testing were assisted by community health workers, who then collected feedback on test acceptability via follow-up questionnaires. Results (if a Case Study enter NA) A total of 325 individuals participated in the study from Sept 2022-June 2023. 52% of participants are minority ethnicity, including 35% African American and 17% Latino. 11% of participants are uninsured and 32% of participants are from households with income lower than 25,000 a year. We surveyed our participants on their opinion of COVID-19 and Flu testing and vaccination, majority of our participants have had more experience in COVID-19 (92% had been tested and 93% had been vaccinated) than Flu (64% had been tested and 85% had been vaccinated). 96% consider COVID-19 testing tolerable, with major barrier of being tested is fear of painful sampling (49%). PCR testing is the dominant testing method in the community (&amp;gt; 40%) for COVID-19, while only 16% received antigen testing. Conclusion Our findings suggest that while participants recognized the role of COVID-19 testing, there were significant barriers to access and uptake of testing, including concerns about painful sampling, inconvenience, and a lack of trust in the healthcare system. Participants also expressed a desire for clearer information about testing and more accessible testing sites. Participants have less experience with Flu testing and many of whom had never been tested in the past. Our study highlights the need for targeted community education and outreach efforts to increase testing uptake. Development and implementation of these efforts would better prepare us for combating other commutable diseases of public health significance in the future.

American Indian census rolls: An underutilized source of historical demographic information on tribal populations

Historical information on tribal populations in the United States is incomplete. American Indians and Alaska Natives were not enumerated with the general population until the 1940 decennial census. However, Indian Census Rolls were produced for the period 1885 &amp;ndash; 1940 under the auspices of the Bureau of Indian Affairs in the U.S. The information given in the Indian Census Rolls varies but usually includes the roll number, age, gender, tribal identity, and relationship to the head of the family. In this paper, we present background information on Indian Census Rolls and demonstrate how the digitized microfiche census roll schedules can be assembled into an Excel file. We also provide examples of the potential uses of Indian Census Rolls. We conclude that Indian Census Rolls can not only help bridge the gaps in the historical demography of American Indians but also provide the basis for a clearer picture of the current and future demographic characteristics of American Indians.

Genetic relationships of populations of the Black Kite Milvus migrans (Accipitriformes: Accipitridae) in the east of its range in Asia and Australia

While the Black Kite Milvus migrans is one of the most widespread birds of prey, occurring over Eurasia, Africa and Australia, it remains poorly understood outside of Europe, with southeast Asian populations particularly mysterious as their taxonomy is based on outdated morphological data. The subspecies M. m. formosanus, described in 1920, is thought to inhabit Taiwan and Hainan; however, populations in these areas have experienced dramatic changes over the past fifty years. Furthermore, M. m. formosanus is the only officially recognised subspecies for which almost no genetic data is yet available. Based on two mitochondrial genes, we compared Taiwanese Black Kites with northeast Asian and Japanese M. m. lineatus, Indian M. m. govinda and Australian M. m. affinis to reconstruct details of their population history. While Indian and Australian Black Kites are descendants of the same population, they do not share common haplotypes, probably having diverged by the end of the last glaciation. The Japanese population is distinctive in showing genetic uniformity, and it may be isolated from the mainland population. Nesting Taiwanese kites carry two previously known M. m. lineatus haplogroups and a new haplogroup possibly inherited from M. m. formosanus previously occurring in the area. A recent decline in the local population, along with expansion of M. m. lineatus, most likely led to Taiwan now being inhabited by descendants of both subspecies, which form two genetically isolated populations in southern and northern Taiwan.

Theia 456: Tidally Shredding an Open Cluster

The application of clustering algorithms to the Gaia astrometric catalog has revolutionized our census of stellar populations in the milky Way, including the discovery of many new dispersed structures. We focus on one such structure, Theia 456 (COIN-Gaia-13), a loosely bound collection of ∼320 stars spanning ∼120 pc that has previously been shown to exhibit kinematic, chemical, and gyrochronal coherency, indicating a common origin. We obtain follow-up radial velocities and supplement these with Gaia astrometry to perform an in-depth dynamical analysis of Theia 456. By integrating stellar orbits through a Milky Way potential, we find the currently dispersed structure coalesced into a small cluster in the past. Via Bayesian modeling, we derive a kinematic age of 245 ± 3 Myr (statistical), a half-mass–radius of 9 ± 2 pc, and an initial one-dimensional velocity dispersion of 0.14 ± 0.02 km s−1. Our results are entirely independent of model isochrones, details of stellar evolution, and internal cluster dynamics, and the statistical precision in our age derivation rivals that of the most precise age-dating techniques known today, though our imperfect knowledge of the Milky Way potential and simple spherical model for Theia 456 at birth add additional uncertainties. Using posterior predictive checking, we confirm these results are robust under reasonable variations to the Milky Way potential. Such low-density structures that are disrupted by the Galactic tides before virializing may be ubiquitous, signifying that Theia 456 is a valuable benchmark for studying the dynamical history of stellar populations in the Milky Way.

Population Genomics of Adaptive Radiations: Exceptionally High Levels of Genetic Diversity and Recombination in an Endemic Spider From the Canary Islands.

The spider genus Dysdera has undergone a remarkable diversification in the oceanic archipelago of the Canary Islands, with ~60 endemic species having originated during the 20 million years since the origin of the archipelago. This evolutionary radiation has been accompanied by substantial dietary shifts, often characterised by phenotypic modifications encompassing morphological, metabolic and behavioural changes. Hence, these endemic spiders represent an excellent model for understanding the evolutionary drivers and to pinpoint the genomic determinants underlying adaptive radiations. Recently, we achieved the first chromosome-level genome assembly of one of the endemic species, D. silvatica, providing a high-quality reference sequence for evolutionary genomics studies. Here, we conducted a low coverage-based resequencing study of a natural population of D. silvatica from La Gomera island. Taking advantage of the new high-quality genome, we characterised genome-wide levels of nucleotide polymorphism, divergence and linkage disequilibrium, and inferred the demographic history of this population. We also performed comprehensive genome-wide scans for recent positive selection. Our findings uncovered exceptionally high levels of nucleotide diversity and recombination in this geographically restricted endemic species, indicative of large historical effective population sizes. We also identified several candidate genomic regions that are potentially under positive selection, highlighting relevant biological processes, such as vision and nitrogen extraction as potential adaptation targets. These processes may ultimately drive species diversification in this genus. This pioneering study of spiders that are endemic to an oceanic archipelago lays the groundwork for broader population genomics analyses aimed at understanding the genetic mechanisms driving adaptive radiation in island ecosystems.

Contrasting Genomic Diversity and Inbreeding Levels Among Two Closely Related Falcon Species With Overlapping Geographic Distributions.

Genomic resources are valuable to examine historical demographic patterns and their effects to better inform management and conservation of threatened species. We evaluated population trends and genome-wide variation in the near-threatened Orange-breasted Falcon (Falco deiroleucus) and its more common sister species, the Bat Falcon (F. rufigularis), to explore how the two species differ in genomic diversity as influenced by their contrasting long-term demographic histories. We generated and aligned whole genome resequencing data for 12 Orange-breasted Falcons and 9 Bat Falcons to an annotated Gyrfalcon (F. rusticolus) reference genome that retained approximately 22.4 million biallelic autosomal SNPs (chromosomes 1-22). Our analyses indicated much lower genomic diversity in Orange-breasted Falcons compared to Bat Falcons. All sampled Orange-breasted Falcons were significantly more inbred than the sampled Bat Falcons, with values similar to those observed in island-mainland species comparisons. The distribution of runs of homozygosity showed variation suggesting long-term low population size and the possibility of bottlenecks in Orange-breasted Falcons contrasting with consistently larger populations in Bat Falcons. Analysis of genetic load suggests that Orange-breasted Falcons are less likely to experience inbreeding depression than Bat Falcons due to reduced inbreeding load but are at elevated risk from fixation of deleterious gene variants and perhaps a reduced adaptive potential. These genomic analyses highlight differences in the historical demography of two closely related species that have influenced their current genomic diversity and should result in differing strategies for their continued conservation.

Mitochondrial Genomes of Korean Native Black Goats Reveal Shared Phylogeographic Patterns and Demographic History.

This study explores the phylogeny of Korean native black goats through analysis of their complete mitochondrial DNA. The National Institute of Animal Science has gathered genetic material on purebred goats from isolated regions such as Tongyeong, Dangjin, and Jangsu, and is actively breeding them on a national level. These populations, however, are small and exhibit high inbreeding rates, highlighting the urgent need to preserve genetic diversity. The haplotype diversity within this native group is 0.659, with 39 haplotypes identified. By contrast, including international breeds in the analysis increases the overall haplotype diversity to 0.925 with 203 haplotypes identified, highlighting the limited genetic diversity among native black goats. For phylogenetic assessment, a neighbor-joining tree and median-joining network were constructed using identified haplogroups (A, B, C, D, G, and F) from prior studies. The results pinpoint the native black goats as closely related to, but distinct from, Haplogroup A with a bootstrap value of 98, establishing them as a separate clade (A'). This supports the notion of a shared ancestry with various global populations. This research provides essential data on the origins and evolutionary history of Korean native black goats, supporting conservation and breeding efforts aimed at enhancing genetic diversity.

Too big to purge: persistence of deleterious Mutations in Island populations of the European Barn Owl (Tyto alba).

A key aspect of assessing the risk of extinction/extirpation for a particular wild species or population is the status of inbreeding, but the origin of inbreeding and the current mutational load are also two crucial factors to consider when determining survival probability of a population. In this study, we used samples from 502 barn owls from continental and island populations across Europe, with the aim of quantifying and comparing the level of inbreeding between populations with differing demographic histories. In addition to comparing inbreeding status, we determined whether inbreeding is due to non-random mating or high co-ancestry within the population. We show that islands have higher levels of inbreeding than continental populations, and that this is mainly due to small effective population sizes rather than recent consanguineous mating. We assess the probability that a region is autozygous along the genome and show that this probability decreased as the number of genes present in that region increased. Finally, we looked for evidence of reduced selection efficiency and purging in island populations. Among island populations, we found an increase in numbers of both neutral and deleterious minor alleles, possibly as a result of drift and decreased selection efficiency but we found no evidence of purging.

Deep Fungal Infections of Skin and Role of Histopathology in Diagnosis

Abstract Introduction: Deep mycoses acquired by penetrating trauma to the skin can have varied and sometimes atypical morphological presentations resulting in diagnostic dilemmas and delay in treatment onset. Histopathology can be a useful tool in not only diagnosing but also differentiating various deep mycoses. Aims and Objectives: To observe various morphological presentations and histopathological features of deep fungal infections. Materials and Methods: A retrospective multi-centric study was conducted from 2010 to 2020 at 16 centres. The cases with diagnoses of various deep mycoses were included in the study. The patients presenting with cutaneous manifestations were included in the study. Their demographic details, history, presenting signs and symptoms, morphological presentations, histopathological features and treatment details were collected from the case sheets. Results: A total of 124 cases were found from the case records. The most common type was chromoblastomycosis (42) followed by mycetoma (28) and rhinosporidiosis (17). The mean age was 43.76 ± 5.44 years. The average duration of symptoms before presentation was between 2 months to 10 years (average 2.5 ± 1.33 years). Male to female ratio was 1:0.7. Prior history of trauma was recorded in 36% of cases. Chromoblastomycosis cases presented with verrucous to atrophic plaques with black dots on the surface and histopathology findings included pesudoepitheliomatous hyperplasia, epithelioid cell granulomas, copper penny bodies within granulomas and abscesses. Rhinosporidiosis cases had polypoid grape-like lesions in the nose and eyes most commonly with histopathology findings of abundant thick-walled sporangia in dermis packed with thousands of spores. Eumycetoma patients had pigmented, indurated swelling with multiple sinuses discharging black granules and histopathology showed dermal abscesses and foreign body granulomatous reaction with PAS-positive hyphae. Histoplasmosis patients presented with few to multiple nodulo-pustular lesions on skin and palatal ulcers while small basophilic bodies packed in the cytoplasm of histiocytes were noted in histopathology. Phaeohyphomycosis cases presented as deep-seated cystic lesions and biopsy revealed deepithelialized cysts in the dermis or hypodermis with lumen showing necro inflammatory debris and fungal hyphae. Sporotrichosis cases had erythematous, tender nodules and papules either as single lesions or as multiple lesions arranged in a linear fashion and histopathology showed pseudoepitheliomatous hyperplasia of epidermis, loose to well-defined epithelioid cell granulomas and microabscesses. Spores were found in two cases. Cryptococcosis patient had multiple umbilicated lesions resembling giant molluscum contagiosum loose epithelioid cell granulomas and medium-sized spores lying in both intra and extracellularly on histopathology. Penicilliosis patients had nodulo-pustular lesions and histopathology showed an admixture of histiocytes, epithelioid cells, plasma cells, lymphocytes and polymorphs in the dermis with the presence of yeast-like spores in the cytoplasm of histiocytes and epithelioid cells. Entomophthoromycosis cases presented with asymptomatic subcutaneous firm swelling with loss of skin pinchability. Conclusion: Though clinical findings of deep fungal infections are characteristic similar morphology and atypical presentations can be sometimes confusing. Histopathology is useful for confirming the diagnosis.

Snow leopard phylogeography and population structure supports two global populations with single refugial origin

AbstractSnow leopards (Panthera uncia) inhabit the mountainous regions of High Asia, which experienced serial glacial contraction and expansion during climatic cycles of the Pleistocene. The corresponding impacts of glacial vicariance may have alternately promoted or constrained genetic differentiation to shape the distribution of genetic lineages and population structure. We studied snow leopard phylogeography across High Asia by examining range-wide historical and contemporary genetic structure with mitochondrial DNA and microsatellite markers. We genotyped 182 individuals from across snow leopard range and sequenced portions of the mitogenome in a spatially stratified subset of 80 individuals to infer historical biogeographic and contemporary patterns of genetic diversity. We observed a lack of phylogeographic structure, and analyses suggested a single refugial origin for all sampled populations. Molecular data provided tentative evidence of a hypothesized glacial refugia in the Tian Shan-Pamir-Hindu Kush-Karakoram mountain ranges, and detected mixed signatures of population expansion. Concordant assessments of microsatellite data indicated two global genetic populations, though we detected geographic differences between historical and contemporary population structure and connectivity inferred from mitochondrial and microsatellite data, respectively. Using the largest sample size and geographic coverage to date, we demonstrate novel information on the phylogeographic history of snow leopards, and corroborate existing interpretations of snow leopard connectivity and genetic structure. We recommend that conservation efforts incorporate genetic data to define and protect meaningful conservation units and their underlying genetic diversity, and to maintain the snow leopard’s adaptive potential and continued resilience to environmental changes.

Centroid opposition-based backtracking search algorithm for global optimization and engineering problems

Evolutionary algorithms (EAs) have a lot of potential to handle nonlinear and non-convex objective functions. Particularly, the backtracking search algorithm (BSA) is a popular nature-based evolutionary optimization method that has attracted many researchers due to its simple structure and efficiency in problem-solving across diverse fields. However, like other optimization algorithms, BSA is also prone to reduced diversity, local optima, and inadequate intensification capabilities. To overcome the flaws and increase the performance of BSA, this research proposes a centroid opposition-based backtracking search algorithm (CoBSA) for global optimization and engineering design problems. In CoBSA, specific individuals simultaneously acquire current and historical population knowledge to preserve population variety and improve exploration capability. On the other hand, other individuals execute the position from the current population's centroid opposition to progress convergence speed and exploitation potential. In addition, an elite process based on logistic chaotic local search was developed to improve the superiority of the current individuals. The suggested CoBSA was validated on a set of benchmark functions and then employed in a set of application examples. According to extensive numerical results and assessments, CoBSA outperformed the other state-of-the-art methods in terms of accurateness, reliability, and execution capability.

THE NUMBER OF DISTAL RADIAL FRACTURES IN THE ELDERLY WILL INCREASE BY MORE THAN HALF BY 2040: PREDICTION MODELLING USING NATIONAL DATA

The aim was to predict the number and incidence of distal radius fractures in Scotland over the next two decades according to age group, categorised into under 65yrs(65) and 65yrs and older (65), and estimate the potential increased operative burden.The number of distal radius fractures in Scotland was isolated from the Global Burden of Disease database and this was used, in addition to historic population data and published population estimates, to create a multivariable model allowing incorporation of age group, sex and time. A Negative Binomial distribution was used to predict incidence in 2030 and 2040 and calculate projected number of fractures. A 20.4% operative intervention rate was assumed (local data).In terms of number of fractures, there was a projected 61% rise in the 65 group with an overall increase of 2099 fractures per year from 3417 in 2020 (95% confidence interval (CI) 2960 – 3463) to 5516 in 2040 (95% CI 4155 – 5675). This was associated with 428 additional operative interventions per year for those 65yrs. The projected increase between 2020 and 2040 was similar in both sexes (60% in females, 63% in males), however the absolute increase in fracture number was higher in females. There was a 4% projected fall in the number of fractures in those 65.Incidence of distal radius fractures is expected to considerably increase over the next two decades due to a projected increase in the number of fractures in the elderly. This has implications for associated morbidity and healthcare resource use.

Genomic signatures of inbreeding and mutation load in tree ferns.

Ferns (Pteridophyta), as the second largest group of vascular plants, play important roles in ecosystem functioning. Homosporous ferns exhibit a remarkable range of mating systems, from extreme inbreeding to obligate outcrossing, which may have significant evolutionary and ecological implications. Despite their significance, the impact of genome-wide inbreeding on genetic diversity and mutation load within the fern lineage remain largely unexplored. In this study, we utilized whole-genome sequencing to investigate the genomic signatures of inbreeding and genetic load in three Alsophila tree fern species. Our analysis revealed extremely high inbreeding in A. spinulosa, in contrast to the predominantly outcrossing observed in A. costularis and A. latebrosa. This difference likely reflects divergent mating systems and demographic histories. Consistent with its extreme inbreeding propensity, A. spinulosa exhibits reduced genetic diversity and a pronounced decline in effective population size. Comparison of genetic load revealed an overall reduction in deleterious mutations in the highly inbred A. spinulosa, highlighting that long-term inbreeding may have contributed to the purging of strongly deleterious mutations, thereby prolonging the survival of A. spinulosa. Despite this, however, A. spinulosa carries a substantive realized genetic load that may potentially instigate future fitness decline. Our findings illuminate the complex evolutionary interplay between inbreeding and mutation load in homosporous ferns, yielding insights with important implications for the conservation and management of these species.

Confucian culture, public education expenditure, and economic growth

Confucian culture has been found to have significant effects on economic outcomes, yet current studies seldom delve into its impact on regional economic growth in China and the role of government behavior as a mechanism. From the perspective of government response to public demands for education, this paper examines whether Confucian culture fosters economic growth by driving up public education expenditure. Using panel data at the prefecture-level over 2003–2018 and taking the historical population density of jinshi in the Ming and Qing Dynasties as the proxy of the Confucian culture, the empirical analysis is done mainly through pooled OLS and IV analysis. Results show that Confucian culture has a significant and positive effect on economic growth, which can be partially explained by its positive influence on public education expenditure. The channel still holds after controlling human capital in regression. Further discussion of the clan culture and local governors’ cultural backgrounds suggests that higher public education expenditure results from the local government’s passive response to public demands for education. Thus, local governments are suggested to widen and improve the channels for expressing public demands and increase public education expenditure while balancing public demands and the need to boost economic growth.

Unveiling the Genome-Wide Consequences of Range Expansion and Mating System Transitions in Primula vulgaris.

Genetic diversity is heterogeneously distributed among populations of the same species, due to the joint effects of multiple demographic processes, including range contractions and expansions, and mating systems shifts. Here, we ask how both processes shape genomic diversity in space and time in the classical Primula vulgaris model. This perennial herb originated in the Caucasus region and was hypothesized to have expanded westward following glacial retreat in the Quaternary. Moreover, this species is a long-standing model for mating system transitions, exemplified by shifts from heterostyly to homostyly. Leveraging a high-quality reference genome of the closely related Primula veris and whole-genome resequencing data from both heterostylous and homostylous individuals from populations encompassing a wide distribution of P. vulgaris, we reconstructed the demographic history of P. vulgaris. Results are compatible with the previously proposed hypothesis of range expansion from the Caucasus region approximately 79,000 years ago and suggest later shifts to homostyly following rather than preceding postglacial colonization of England. Furthermore, in accordance with population genetic theoretical predictions, both processes are associated with reduced genetic diversity, increased linkage disequilibrium, and reduced efficacy of purifying selection. A novel result concerns the contrasting effects of range expansion versus shift to homostyly on transposable elements, for the former, process is associated with changes in transposable element genomic content, while the latter is not. Jointly, our results elucidate how the interactions among range expansion, transitions to selfing, and Quaternary climatic oscillations shape plant evolution.