Modern Samples Research Articles

Reconsidering the Vaddas of Sri Lanka: Biological and cultural continuity, and misconceptions

This paper aims to re-examine key scholarly works pertaining to the Sri Lankan Vadda, an indigenous community of the island, in order to explore extant research of the said community. Despite considerable progress, lingering misunderstandings and uncertainties persist regarding their origins, connections to prehistoric populations, affiliations with contemporary ethnic groups, and the interrelationships among different Vadda communities across the island. Furthermore, uncertainties persist regarding the authenticity of Vadda skeletal remains and the adequacy of archaeological samples, which often suffer from fragmentation and incompleteness. It is this archaeological sample that has been used to draw conclusions about the cultural and biological continuity of the Mesolithic population or the Balangoda man (Homo sapiens balangodensis) with the Vaddas and the modern populations of the island, thus perhaps distorting interpretations. Similarly, this study underscores concerns regarding the representation of modern samples collected from diverse Vadda clans inhabiting various ecological zones and engaging in different subsistence practices, potentially skewing the conclusions of preceding research. In this study, fresh ethnoarchaeological data are used to examine some misconceptions prevailing about the Warugas (clans) as well as the use of the term Wanniyalaetto as a synonym for Vaddas. Given the rapid acculturation of Vaddas, there is a pressing need for continued interdisciplinary investigations into the Vadda communities, encompassing different Warugas and geographic regions, to ensure a better understanding of their socio-cultural dynamics with the aim of enhanced insight into their evolutionary pathways.

Interpreting depositional environments from modern floodplain sediments using optically stimulated luminescence

We investigate how luminescence signals imprinted on fluvial sediments vary depending on the depositional environment and vary through time in the same river. We collected sediment samples from four geomorphically distinct locations on the modern floodplain and modern point bar on the Buffalo River in northwest Arkansas, USA, in order to determine if different depositional environments are associated with distinct bleaching characteristics in the sediments. Our analysis revealed that all samples from different depositional environments yielded ages consistent with modern deposition. The samples collected from the floodplain and bar head contained a higher proportion of grains with residual doses, indicative of incomplete bleaching during transport, while samples from the mid‐bar and bar tail appeared well bleached. Our results are particularly intriguing for two significant reasons. First, they highlight distinct equivalent dose distributions in different depositional environments. Second, they shed light on an intriguing relationship: despite generally well‐bleached modern floodplain samples, ancient sediments from corresponding terraces displayed equivalent dose (De) distributions that suggest partial bleaching in some cases. This research contributes to the growing body of work that seeks to establish a relationship between luminescence properties and sediment transport processes and offers valuable insight into how luminescence signals vary locally in modern fluvial deposits, which can help guide the interpretation of older fluvial deposits.

IDog: a multi-omics resource for canids study.

iDog (https://ngdc.cncb.ac.cn/idog/) is a comprehensive public resource for domestic dogs (Canis lupus familiaris) and wild canids, designed to integrate multi-omics data and provide data services for the worldwide canine research community. Notably, iDog 2.0 features a 15-fold increase in genomic samples, including 29.55 million single nucleotide polymorphisms (SNPs) and 16.54 million insertions/deletions (InDels) from 1929 modern samples and 29.09 million SNPs from 111 ancient Canis samples. Additionally, 43487 breed-specific SNPs and 530 disease/trait-associated variants have been identified and integrated. The platform also includes data from 141 BioProjects involving gene expression analyses and a single-cell transcriptome module containing data from 105057 Beagle hippocampus cells. iDog 2.0 also includes an epignome module that evaluates DNA methylation patterns across 547 samples and chromatin accessibility across 87 samples for the analysis of gene expression regulation. Additionally, it provies phenotypic data for 897 dog diseases, 3207 genotype-to-phenotype (G2P) pairs, and 349 dog disease-associated genes, along with two newly constructed ontologies for breed and disease standardization. Finally, 13 new analytical tools have been added. Given these enhancements, the updated iDog 2.0 is an invaluable resource for the global cannie research community.

Complete mitochondrial genome of <I>Clupeonella abrau</I> (Maliatsky, 1930) (Clupeiformes), an endemic species of freshwater fish from lake Abrau (Russia)

The Abrau sprat (Tyulka or Sardelka) Clupeonella abrau (Maliatsky, 1930) is an endemic fish of Lake Abrau (Krasnodar Territory). The full mitogenome of C. abrau (16650 bp in length, with a conservative gene arrangement for Clupeidae) demonstrates 98.8% similarity with the mitogenome of a related species, the Black Sea-Caspian tulka (C. cultriventris) from the Black Sea. The sequence of the COX1 gene was also studied in a museum specimen collected in Lake Abrau in 1938. Variability in modern Abrau sprat COX1 locus in about 0.15%, the difference between C. abrau and C. cultriventris is 1.2%, and the difference between the Museum and modern samples of tulka from Lake Abrau is 0.92%. It has been confirmed that the Abrau sprat is present in the fish community and capable of reproducing in the lake. Various alternative scenarios for the settlement of Lake Abrau have been proposed.

Sclerochronology and oxygen isotope variations in modern Conomurex luhuanus shells: An archive for reconstructing palaeotemperature and shellfish gathering on the Great Barrier Reef, Australia

The marine gastropod Conomurex luhuanus is a common component of Holocene archaeological shell deposits in the Western Indo-Pacific region. Oxygen isotope ratios recorded in shells of C. luhuanus from the Great Barrier Reef potentially provide high-resolution data on palaeoclimatic conditions and the exploitation of coastal marine resources. However, the application of this species as a palaeoclimate and seasonal foraging archive has yet to be investigated. We employ sclerochronology techniques to analyse oxygen isotope variations in modern, live-collected shells to evaluate the efficacy of this species in recording modern environmental factors, such as sea-surface temperature (SST). We collected live C. luhuanus during the cold season (August and September), in two separate years (2019 and 2023), from reef-flat intertidal zones. Shell growth increments were studied in section and high-resolution carbonate samples were collected from the lip portion and along the body whorl to test whether shell carbonate is deposited in oxygen isotopic equilibrium with seawater and to decipher the shell growth pattern of this species. Measured δ18Oshell ranges between −0.2 and − 1.8 ‰ (VPDB) in modern samples. Despite showing variability in growth rates, including a remarkable growth stop/slowdown during the cool season that is punctuated by a red zone with closely spaced growth increments, our findings reveal that C. luhuanus deposits its aragonite shells at (or close to) equilibrium with its surrounding environment. When sampled at high resolution (sub-seasonally), oxygen isotopes can be used to reconstruct the full annual SST range. The estimated SSTs closely match the range of instrumental SSTs measured in the study area, whilst the last deposited (edge) shell-calculated SST can be used to determine the season of animal death. This study shows that well-preserved shells of C. luhuanus can serve as excellent high-resolution palaeotemperature archives for the tropical reef-flat zone. This research underpins the use of this species in future research to determine human-environment interactions and reconstruction of palaeoclimate from archaeological and fossil samples in the Western Pacific Ocean.

Environmental associations and the paleoecological significance of the genus Pyxidicula Ehrenberg,1838 and Pyxidicula muskegii sp. nov. in the Hudson and James Bay region peatlands, Canada

An environmental proxy routinely used in paleoecological studies of peatlands is testate amoebae, which are used to infer successional and hydrological shifts through time. However, since many species of protists globally remain undescribed, important ecological information about community assemblages and their interaction with environmental conditions in both the past and present has potential gaps. During the analysis of testate amoeba assemblages from peat cores across the Hudson and James Bay region of Canada, a testate amoeba that has not been formally described was discovered with high abundance in subfossil assemblages (up to 50%). We describe this new species, Pyxidicula muskegii sp. nov., using morphometric measurements of tests from these peat core records and demonstrate its environmental preferences using modern samples collected from the same region. The hemispheric shape and irregular areolar surface pattern on the test, along with its preference for lawns in both fens and bogs, support that P. muskegii is a new species. This species is also found in much lower relative abundance in modern samples (<3%) than in paleo-peat core records. This difference in modern and paleo-assemblage suggests that there is a taphonomic bias in their relative abundance with depth, which we attribute to their organic test that is less prone to decomposition. Therefore, it is critical to include rare taxa within future transfer function models to incorporate their environmental tolerances and improve model predictions.

Estimation of sex assigned at birth using dental crown and cervical measurements in a modern global sample.

Despite developing prior to the appearance of secondary sexual characteristics of the skeleton, the permanent dentition exhibits sexual dimorphism. Therefore, teeth can serve as a means to estimate sex assigned at birth even in young individuals. This project takes a large global sample of maximum dimensions of the crown as well as measurements of the crown at the cervix to explore sexual dimorphism. Dimorphism is noted in teeth throughout the dental arcade, particularly in the canines. We provide sectioning points as well as the probability of correct classification (ranging from 50.9% to 81.3%) for each measurement to aid the practitioner in sex estimation from the dentition. This research provides a method to estimate sex without arbitrary population specifications. We argue for a global approach that incorporates more population variation to remove the need to estimate "ancestry," (which in actuality is translated to a social race category) and therefore does not force sexual dimorphism-related variation into these mutable and ambiguous categories. Further, this paper demonstrates the utility of the dentition as an additional indicator to aid with the estimation of sex assigned at birth in forensic anthropology. The goal of this research is to better understand the expression of sexual dimorphism across the skeleton in a global context.

Relationships between pollen assemblages and modern vegetation of the southern Gaoligong Mountains region, southwest China

Comprehensive understanding of the modern pollen–vegetation relationship is crucial for utilizing fossil pollen to reconstruct palaeovegetation, especially in mountainous areas of southwestern China. In this study, we present forty-five modern surface samples collected from five different vegetation communities of the southern Gaoligong Mountains region, and the vegetation composition was investigated at each sample site. The modern pollen assemblages were analyzed through multivariate analysis to evaluate the relationships between vegetation types and pollen assemblages, and to investigate the representation of major pollen types in different vegetation types. The results indicate that the surface pollen assemblages of different vegetation types reliably represent the modern vegetation. The median R-values of dominant pollen taxa in the Gaoligong Mountains region can be ordered as follows: Pinus > Alnus > Poaceae > evergreen Quercus. The over-representation of Pinus pollen, attributed to its high productivity and strong dispersal ability, makes it the dominant component of exotic pollen. Conversely, the under-representation of evergreen Quercus suggests that the presence of its pollen within a sample might indicate the growth of the local parent plant in the study area. The human activities in the region have a recognizable effect on the surface pollen spectra and also exert a significant negative impact on pollen diversity. Our study supplements the modern pollen database of the mountain regions in southwestern China, and provides representative modern pollen analogues to interpret fossil pollen records from southwestern China and similar regions.

Sex estimation using metrics of the innominate: A test of the DSP2 method.

Sex estimation is a critical component of the biological profile, and forensic anthropologists may use a variety of sex estimation methods depending upon the degree of completeness and state of preservation of the skeletal remains being analyzed. The innominate is widely accepted to be the most sexually dimorphic skeletal element. The Diagnose Sexuelle Probabiliste (DSP) method, which uses 10 measurements of the innominate, was introduced in 2005 and updated as DSP2 in 2017. While DSP2 has been reported to have high classification accuracy rates in studies of South American and European populations, the method has not been widely tested in US samples, and few US practitioners incorporate this method into their casework. The goal of this study was to test the reliability and accuracy of DSP2 using a large, modern sample from the US (n = 174). Two observers, blinded from demographic information associated with each specimen, collected the DSP2 metrics. Intra- and interobserver error analyses showed acceptable levels of agreement for all measurements, except for IIMT. Classification accuracies exceeded 95%, with minimal sex bias, for both observers and using various measurement combinations; however, an inclusivity sex bias occurred with more males reaching the 0.95 posterior probability threshold required by DSP2 to provide a sex classification estimate. Based on its high accuracy, forensic anthropologists in the US may consider incorporating DSP2 into their casework, although we recommend excluding IIMT and using SPU with caution. Additional methods will continue to be needed when the posterior probability threshold is not reached.

Genetic consequences of the dramatic decline in the north-west pre-caspian saiga (Saiga tatarica tatarica) population: a comparison of modern and museum samples on mtDNA and microsatellite loci

The North-West Pre-Caspian saiga (Saiga tatarica tatarica) population numbers was about 800 thousand individuals in the middle of the last century. There was a dramatic decline at the end of the 20th century, and by 2015 this saiga population numbers and was about five thousand animals. Our paper presents the results of microsatellite loci and of the mtDNA control region analysis obtained for the museum saiga samples from the North-West Pre-Caspian population, collected at the peak of their numbers in the 1950s. We compared these data with our previous results for the samples collected during the population depression in1999–2016. There were no noticeable differences of mtDNA control region diversity between the museum and modern saiga samples. The most vivid genetic consequence of the severe decline in population numbers was a significant increase of the inbreeding coefficient (Fis) calculated from the microsatellite loci.

Ancient and modern bone diagnosis: Towards a better understanding of chemical and structural feature alterations

Chemical and structural alterations hold great importance in the field of diagenesis. Attenuated Total Reflectance − Fourier Transform Infrared Spectroscopy (ATR-FTIR) is a valuable method for examining bio-apatite composition changes. Infrared spectroscopy (IR) and X-ray diffraction (XRD) were employed to analyze both modern and archaeological bone specimens. Organic and mineral component changes in modern and ancient samples were investigated. Ancient bone samples were collected from two archaeological sites in Jordan, dating back to the Iron and Byzantine ages. IR results indicated that collagen cross-links and mineral maturity are higher in modern bones compared to ancient bones. Additionally, the crystallinity index is higher in modern bones than in archaeological bones, while the carbonate to phosphate ratio (C/P) is lower in modern bones than in ancient ones. Curve fitting was applied to reveal the carbonate substitution inside the hydroxyapatite lattice within the IR region from 850 to 890 cm−1. A2-type carbonates (identified as υ2 of CO32−) denote hydroxyl site substitution, and B-type carbonates represent a substitution to the phosphate site. The full width at half maximum (FWHM) of the peak at 604 cm−1 from IR spectra reveals that crystallinity is higher in modern bones, as confirmed by the FWHM of the (002)-apatite pattern in XRD. Statistical analysis was conducted to validate these findings, ensuring the robustness of the results. Finally, the results obtained in this investigation align with previous literature reports regarding ATR-FTIR ratios. This suggests that modern bones have better crystallinity compared to ancient bones. Furthermore, the ATR-FTIR ratios indicate that the hydroxyl and phosphate sites of modern bones undergo more substitution than older bones. The findings of this study not only enhance our understanding of the diagnostic processes in archaeological bone specimens but also have broader implications for fields such as archaeology, anthropology, and forensics, where the analysis of bone composition and structural changes can provide valuable insights into the history and characteristics of ancient remains.

МЕТОДИКА ЕКСПЕРИМЕНТАЛЬНИХ ДОСЛІДЖЕНЬ СПРОЩЕНОЇ МОДЕЛІ БПЛА ТИПУ БІКОПТЕР

Modern aircraft are usually statically unstable objects. Due to this, increased maneuverability and controllability is achieved. One of the promising directions is the development and implementation of UAVs of the bicopter or convertible type. Their movement is provided by two screw electric drives. The non-identity of the engine parameters and the peculiarities of the movement of UAVs of this type cause special requirements for the control systems. To ensure sustainability, modeling and conducting research with the help of various tools is necessary. The most available models of unstable movements are pendulum devices of various types, which allow studying stabilization processes. The purpose of the work is to use a computer stabilization system of a simplified bicopter UAV model by changing the thrust of the engines. The tasks of the work are: development of a computer stabilization system for the angle of pitch or roll, creation and verification of stabilization algorithms on a laboratory bench using an ARDUINO controller, research of the functional capabilities of angular stabilization circuits. The object of the study: a computer control system of an aircraft that performs the task of stabilizing a UAV. Subject of research: processes of stabilization of the angular position of a simplified bicopter model. When performing the work, a control law using angular and angular velocity feedback was chosen. A variant of aircraft stabilization when using engine thrust control is proposed. The control law of the computer stabilization system, which is implemented on the ARDUINO controller, was selected and tested. The applied value of the work is the further use of the obtained results in modern samples of bicopters.

Методика «Схематизация» в цифровом формате для оценки уровня развития наглядно-образного мышления старших дошкольников

<p>The development of imaginative thinking is one of the main tasks of educational work with preschoolers, because it allows the child to be successful in preschool activities, where the most favorable conditions for the formation of age new achievements are formed. The need for diagnostic tests to determine the level of imaginative thinking of preschoolers is related both to the need to assess the effectiveness of educational work with children, and to identify the level of development of the child. The most informative and reliable results of the assessment of cognitive processes are provided by the use of standardized test. In Russian psychology, there is only one such test - "Schematization" (author R.I. Bardin). This test was created and standardized at the end of the last century and its psychometric characteristics and assessment standards need to be updated for a modern sample. The article presents the results of the re-standarization of this test. The experimental sample of the study consisted of N = 2425 children of senior preschool age: children 5-6 years old (M = 66 months; SD = 3.09 months; n = 974) and 6-7 years old (M = 77 months; SD = 3.21 months; n = 1451). For psychometric verification, confirmatory factor analysis, Cronbach's alpha and McDonald's omega coefficients, Spearman correlation coefficient, Mann-Whitney U criterion and two-factor analysis of variance were used. The norms were calculated using percentile normalization. The obtained results showed the conformity of the test with psychometric requirements and allowed us to determine the current norms for the development of imaginative thinking of older preschool children.</p>

Beijing Central Asian Outbreak strain cluster of Mycobacterium tuberculosis detected in Irkutsk region, Russia

Background. Irkutsk region maintains a high incidence rate of multidrug-resistant (MDR) tuberculosis (TB). Detection of MDR-associated Mycobacterium tuberculosis strains in Irkutsk region requires dynamic assessment of the TB pathogen population, taking into account the emergence of a new resistant variant of Beijing Central Asian Outbreak (CAO).The aim of the study. To assess changes in the genotypic structure of M. tuberculosis strains circulating in the Irkutsk region over a ten-year period.Materials and methods. A total of 732 M. tuberculosis strains (196 strains for 2021– 2022, 536 strains for 2011–2015) were studied using MIRU-VNTR and SNP typing.Results. The MDR level increased to 67.4 % with an increase of pre-extensive drug resistance (pre-XDR) (33.2 %) (p < 0.001). In the modern sample, the dominance of the Beijing genotype increased (83.7 %) due to an increase in the proportions of the B0/W148 (38.8 %) and CAO (12.8 %) subtypes with a stable overall level of Central Asian Russian (36.8 %) and other Beijing strains (8.2 %). Strains other than the Beijing genotype belonged mainly to the Euro-American lineage (Lineage 4): LAM (8.9 %), Ural (2.7 %), Haarlem (2.0 %), S (0.5 %) and L4-unclassified (5.3 %); 25 isolates were not classified. In the 2011–2015 sample, LAM was more common than in the modern sample (10.8 % vs. 3.6 %; p < 0.01). The increase in MDR and preXDR was statistically significant among Beijing B0/W148 strains (93.4 % vs. 66.1 %; p < 0.001).Conclusion. Unfavorable trends of significant spread of MDR and pre-XDR of the Beijing genotype strains were revealed. Among the Beijing strains, not only B0/W148 but also the Beijing CAO subtype, which was previously rare in Siberia, are the most successful; they have the highest levels of MDR and pre-XDR and a tendency to widespread distribution in all groups of TB patients.

Oral microbial diversity in 18th century African individuals from South Carolina.

As part of the Anson Street African Burial Ground Project, we characterized the oral microbiomes of twelve 18th century African-descended individuals (Ancestors) from Charleston, South Carolina, USA, to study their oral health and diet. We found that their oral microbiome composition resembled that of other historic (18th-19th century) dental calculus samples but differed from that of modern samples,and was not influenced by indicators of oral health and wear observed in the dentition. Phylogenetic analysis of the oral bacteria, Tannerella forsythia and Pseudoramibacter alactolyticus, revealed varied patterns of lineage diversity and replacement in the Americas, with the Ancestors carrying strains similar to historic period Europeans and Africans. Functional profiling of metabolic pathways suggested that the Ancestors consumed a diet low in animal protein. Overall, our study reveals important insights into the oral microbial histories of African-descended individuals, particularly oral health and diet in colonial North American enslavement contexts.

3775-year-old wood burial supports "wood vaulting" as a durable carbon removal method.

Six-times more carbon dioxide (CO2) is removed each year by terrestrial photosynthesis than fossil fuel emissions. However, the carbon is mostly returned to the atmosphere by decomposition. We found a 3775-year-old ancient wood log buried 2 meters belowground that was preserved far beyond its expected lifetime. The wood had near-perfect preservation, with carbon loss less than 5% compared to a modern sample. The lack of decay is likely due to the low permeability of the compact clay soil at the burial site. Our observation suggests a hybrid nature-engineering approach for carbon removal by burying woody biomass in similar anoxic environments. We estimate a global sequestration potential of up to 10 gigatonnes CO2 per year with existing technology at a low cost of $30 to $100 per tonne after optimization.

Natural and anthropogenic forcing of ecological and environmental changes at Lake Qilu, SW China, since the last deglaciation

The ecological evolution of lakes and their watersheds and the driving mechanisms are a key topic in paleoenvironmental research. However, the relative impacts of human activities and climate change on lake ecosystems since the last deglaciation remain unclear. We conducted a high-resolution study of the chain length distribution and concentration of n-alkanes in a sediment core from Lake Qilu in SW China, to reveal the ecological changes and their controlling factors since 14.6 cal kyr BP. Based on studies of modern samples, short-chain, medium-chain, and long-chain n-alkanes are associated with bacteria/algae, aquatic plants, and terrestrial plants, respectively. Combining the ACL17–33, Paq, and Σn-alkane indices, we found that both aquatic and terrestrial plants proliferated at Lake Qilu from 14.6 to 6 cal kyr BP, which was associated with a relatively warm and wet climate and dynamic strong winds. During the interval from 6 to 2 cal kyr BP, aquatic plants flourished, accompanied by a rapid surge in the regional productivity, primarily due to human activities. After 2 cal kyr BP, anthropogenic eutrophication was the primary cause of the increase in bacteria and algae populations. These results suggest that, before 6 cal kyr BP, climatic factors dominated the n-alkanes distribution; whereas after 6 cal kyr BP, human activities became the primary factor controlling the n-alkanes and ecological changes in Lake Qilu.

Modern Abies, Picea, and Tsuga pollen distribution along the elevation gradient in East Asia

Sub-alpine dark coniferous forests (SCFs) exhibit distinct latitudinal and longitudinal elevation distributions in East Asia. The SCF genera Abies, Picea, and Tsuga produce distinctive pollen and have specific elevation and climate requirements, allowing for the reconstruction of paleo-climatic and paleo-elevational changes from fossil pollen sequences. However, the relationship between SCF elevational distribution and the percentage of coniferous pollen has not been elucidated at the continental scale. In this study, we determined the relationship between Abies, Picea, and Tsuga pollen percentages and SCF elevation distributions in East Asia using an integrated pollen dataset comprising 4863 modern samples. The total percentage of these pollen types showed bimodal patterns with elevation and unimodal patterns with climate. Maximum pollen percentages occurred at elevations of 0–1000 and 2000–4600 m, mean annual temperatures of −5–10 ℃, and mean annual precipitation values of 100–1500 mm. The elevation with the highest proportion of Abies + Picea + Tsuga pollen increased with decreasing latitude: from 500 m (>43°N) to 2300 m (37–43°N), to 3500 m (30–37°N), and to 4000 m (18–30°N). Elevation also exhibited non-monotonic variations with longitude, first increasing from 2500 m (<93°E) to 3500 m (93–102°E), and then decreased to 2500 m (102–113°E) and 500 m (>113°E). The spatial patterns of Abies, Picea, and Tsuga pollen abundance were closely correlated with modern SCF distributions, which are largely modulated by climate and elevation. This study lays the foundation for reconstructing paleo-climate and paleo-elevation variations across East Asia.

Craniometric variation and the ancestry of modern humans.

Ancient and contemporary DNA provide information about geographic variation in the ancestry of present-day humans. All living populations have ancestry from early Homo sapiens originating in sub-Saharan Africa. Populations of Eurasian descent also have a small amount of Neandertal ancestry. This study examines whether craniometric distances between recent modern human samples reflect this geographic variation in ancestry. Among recent modern humans, Eurasians are expected to be more similar to Neandertals, whereas both sub-Saharan Africans and Eurasians are expected to be equidistant from early H. sapiens. Data on 33 craniometric traits from 2524 recent modern humans were compared with data from the literature for Neandertals and early H. sapiens. Mahalanobis distances were computed for each modern specimen to both the Neandertal and early H. sapiens means. These distances were examined for differences between recent humans from sub-Saharan Africa (N = 373) and those of Eurasian descent (N = 2151). Eurasians as a group are significantly closer than sub-Saharan Africans to Neandertals. There is no significant difference between the distances of sub-Saharan Africans and Eurasians to early H. sapiens. The differences between sub-Saharan Africans and Eurasians for both Neandertals and early H. sapiens are as expected. Although there has been geographic differentiation among recent modern humans, including differences in Neandertal admixture, these differences have not affected overall similarity of recent modern sub-Saharan Africans and Eurasians to the earliest samples of H. sapiens.

Untangling the colonization history of the Australo-Pacific reed warblers, one of the world's great island radiations.

Island radiations, such as those of the Australo-Pacific, offer unique insight into diversification, extinction, and early speciation processes. Yet, their speciation and colonization histories are often obscured by conflicting genomic signals from incomplete lineage sorting or hybridization. Here, we integrated mitogenomes and genome-wide SNPs to unravel the evolutionary history of one of the world's most geographically widespread island radiations. The Australo-Pacific reed warblers (Acrocephalus luscinius complex) are a speciose lineage including five species that have become extinct since the 19th century and ten additional species of conservation concern. The radiation spans over 10,000 km across Australo-Papua, Micronesia and Polynesia, including the Mariana, Hawaii and Pitcairn Island archipelagos. Earlier mtDNA studies suggested a stepping-stone colonization process, resulting in archipelago-level secondary sympatry of divergent mtDNA lineages in the Mariana Islands and Marquesas. These studies hypothesised that morphologically similar species on neighbouring islands arose from ecological convergence. Using hDNA from historical museum specimens and modern genetic samples, we show that incomplete lineage sorting and/or gene flow have shaped the radiation of Australo-Pacific reed warblers rather than secondary sympatry. The nuclear genome reconstructs a simpler biogeographic history than mtDNA, showing close relationships between species in the Mariana Islands and Marquesas despite their paraphyletic mtDNA lineages. Gene flow likely involved early and late colonizing waves of the radiation before the loss of ancestral dispersive ability. Our results highlight how collection genomics can elucidate evolutionary history and inform conservation efforts for threatened species.