Trophic position of Otodus megalodon and great white sharks through time revealed by zinc isotopes

Diet is a crucial trait of an animal’s lifestyle and ecology. The trophic level of an organism indicates its functional position within an ecosystem and holds significance for its ecology and evolution. Here, we demonstrate the use of zinc isotopes (δ66Zn) to geochemically assess the trophic level in diverse extant and extinct sharks, including the Neogene megatooth shark (Otodus megalodon) and the great white shark (Carcharodon carcharias). We reveal that dietary δ66Zn signatures are preserved in fossil shark tooth enameloid over deep geologic time and are robust recorders of each species’ trophic level. We observe significant δ66Zn differences among the Otodus and Carcharodon populations implying dietary shifts throughout the Neogene in both genera. Notably, Early Pliocene sympatric C. carcharias and O. megalodon appear to have occupied a similar mean trophic level, a finding that may hold clues to the extinction of the gigantic Neogene megatooth shark.publishedVersio

Subarctic climate for the earliest Homo sapiens in Europe

Acknowledgments The re-excavation of Bacho Kiro Cave was jointly conducted by the National Institute of Archaeology with Museum, Bulgarian Academy of Sciences, Sofia and the Department of Human Evolution at the MPI-EVA. We would like to thank the National Museum of Natural History (Sofia), the Archaeology Department at the New Bulgarian University (Sofia), the Regional Museum of History in Gabrovo, and the History Museum in Dryanovo for assistance on this project and the opportunity to study the Bacho Kiro Cave faunal material. We would like to thank M. Trost, S. Hesse, M. Kaniecki, and P. Dittmann (MPI-EVA) for technical assistance during stable isotope sample preparation. S. Steinbrenner is thanked for technical assistance with TC/EA-IRMS maintenance. Thanks are also due to H. Temming and U. Schwarz (MPI-EVA) for the production of microCT scans and replicas of the sample materials. We would also like to acknowledge the assistance of to D. Veres with taking OSL samples. Last but not least we would like to thank the handling editor, S. Ortman, as well as three anonymous reviewers for their thoughtful comments that greatly improved this manuscript. Funding: The field work was financed by the Max Planck Society. The stable isotope work was funded by the Max Planck Society as part of S.P.’s doctoral project. S.P. was supported by the Max Planck Society and the University of Aberdeen. K.B. was supported by a Philip Leverhulme Prize from The Leverhulme Trust (PLP-2019-284). N.B.’s work was supported as part of a grant by the German Research Foundation (“PALÄODIET” Project 378496604). V.A. was supported by a grant from the Foundation for Science and Technology, Portugal (IF/01157/2015/CP1308/CT0002). Author contributions: The study was devised by S.P., K.B., S.P.M., J.-J.H., and T.T. Archaeological excavation was undertaken by N.S. and T.T. in collaboration with Z.R. and S.P.M. who all contributed contextual information. V.A. collected sedimentological data at the site and untertook micromorphological investigations that provided information on site formation for this study. Zooarchaeological and paleontological analyses were performed by G.M.S. and R.S. OSL dating was carried out by T.L. Radiocarbon dating and recalibration of radiocarbon dates were conducted by H.F. MC-ICPMS analysis was conducted by N.B. and S.P. Sampling, sample processing for oxygen and strontium stable isotope analysis, and TC/EA-IRMS analysis were carried out by S.P. Code and data analyses were written and conducted by S.P. N.-H.T. consulted on statistical analysis and coding. S.P. wrote the paper with input from all authors. Competing interests: The authors declare that they have no competing interests. Data and materials availability: All data needed to evaluate the conclusions in the paper are present in the paper and/or the Supplementary Materials.Peer reviewedPublisher PD

Combining collagen extraction with mineral Zn isotope analyses from a single sample for robust palaeoecological investigations

Collagen extraction from bones or dentine, commonly used for radiocarbon (14C) dating and stable carbon and nitrogen isotope (δ13C and δ15N) analyses, involves the dissolution of the bioapatite of skeletal elements. This fraction is typically disposed of during pretreatment. Here, we test the possibility of utilising this dissolved mineral solution for analysis of the bioapatite zinc isotope composition (δ66Zn). Bioapatite δ66Zn is a novel trophic level indicator similar to collagen δ15N but with isotopic fractionation independent from nitrogen, thus providing additional dietary information. We tested ways to minimise Zn contamination of the dissolved mineral phase during collagen extraction. We then used archaeological bone samples from Ain Difla (Jordan) and Ranis (Germany) to compare δ66Zn values of dissolved bioapatite following our collagen extraction protocol with δ66Zn values from the same sample material dissolved in a metal-free cleanroom. Our results demonstrate that with only minor adjustments to minimise Zn contamination, the dissolved mineral solution from collagen extraction protocols commonly employed for 14C dating and (palaeo)dietary analysis can be used for additional δ66Zn analyses even when collagen extraction does not take place in a cleanroom. Our protocol allows us to gain an additional dietary proxy to complement δ15N trophic level interpretations and perform more robust (palaeo)ecological investigations without further destructive sampling

Reply to Ben-Dor and Barkai: A low Zn isotope ratio is not equal to a low Zn content

However, we are afraid that there was a misunderstanding in the interpretation of our data. Ben-Dor and Barkai (2) wrote that "One explanation presented in the [our] paper was that Neandertals may have consumed body parts and animals that were relatively poor in zinc, like the liver or deer." This sentence is not reflecting our conclusions: We discussed Zn isotope ratios (i.e., 66Zn/64Zn ratio expressed as a δ66Zn value) and not Zn concentrations. To explain low δ66Zn values of the Neandertal tooth, we propose that Neandertals ate food items depleted in heavy Zn isotopes (and therefore enriched in light Zn isotopes), but those foods can have variable Zn contents, independent of the Zn isotope composition as such

Bullet-Shaped Magnetite Biomineralization Within a Magnetotactic Deltaproteobacterium: Implications for Magnetofossil Identification

Magnetite produced by magnetotactic bacteria (MTB) provides stable paleomagnetic signals because it occurs as natural single‐domain magnetic nanocrystals. MTB can also provide useful paleoenvironmental information because their crystal morphologies are associated with particular bacterial groups and the environments in which they live. However, identification of the fossil remains of MTB (i.e., magnetofossils) from ancient sediments or rocks is challenging because of their generally small sizes and because the growth, morphology, and chain assembly of magnetite within MTB are not well understood. Nanoscale characterization is, therefore, needed to understand magnetite biomineralization and to develop magnetofossils as biogeochemical proxies for paleoenvironmental reconstructions. Using advanced transmission electron microscopy, we investigated magnetite growth and chain arrangements within magnetotactic Deltaproteobacteria strain WYHR‐1, which reveals how the magnetite grows to form elongated, bullet‐shaped nanocrystals. Three crystal growth stages are recognized: (i) initial isotropic growth to produce nearly round ~20 nm particles, (ii) subsequent anisotropic growth along the [001] crystallographic direction to ~75 nm lengths and ~30-40 nm widths, and (iii) unidirectional growth along the [001] direction to ~180 nm lengths, with some growing to ~280 nm. Crystal growth and habit differ from that of magnetite produced by other known MTB strains, which indicates species‐specific biomineralization. These findings suggest that magnetite biomineralization might be much more diverse among MTB than previously thought. When characterized adequately at species level, magnetofossil crystallography, and apomorphic features are, therefore, likely to become useful proxies for ancient MTB taxonomic groups or species and for interpreting the environments in which they lived.This study was supported financially by the National Natural Science Foundation of China (grants no. 41920104009, 41890843, and 41621004), The Senior User Project of RVKEXUE2019GZ06 (Center for Ocean Me Mega‐Science, Chinese Academy of Sciences), and the Australian Research Council (grant DP160100805

Isotopic evidence of high reliance on plant food among Later Stone Age hunter-gatherers at Taforalt, Morocco

The transition from hunting-gathering to agriculture stands as one of the most important dietary revolutions in human history. Yet, due to a scarcity of well-preserved human remains from Pleistocene sites, little is known about the dietary practices of pre-agricultural human groups. Here we present the isotopic evidence of pronounced plant reliance among Late Stone Age hunter-gatherers from North Africa (15,000–13,000 cal BP), predating the advent of agriculture by several millennia. Employing a comprehensive multi-isotopic approach, we conducted zinc (δ66Zn) and strontium (87Sr/86Sr) analysis on dental enamel, bulk carbon (δ13C) and nitrogen (δ15N) and sulfur (δ34S) isotope analysis on dentin and bone collagen, and single amino acid analysis on human and faunal remains from Taforalt (Morocco). Our results unequivocally demonstrate a substantial plant-based component in the diets of these hunter-gatherers. This distinct dietary pattern challenges the prevailing notion of high reliance on animal proteins among pre-agricultural human groups. It also raises intriguing questions surrounding the absence of agricultural development in North Africa during the early Holocene. This study underscores the importance of investigating dietary practices during the transition to agriculture and provides insights into the complexities of human subsistence strategies across different regions

Dietary strategies of Pleistocene Pongo sp. and Homo erectus on Java (Indonesia)

During the Early to Middle Pleistocene, Java was inhabited by hominid taxa of great diversity. However, their seasonal dietary strategies have never been explored. We undertook geochemical analyses of orangutan (Pongo sp.), Homo erectus and other mammalian Pleistocene teeth from Sangiran. We reconstructed past dietary strategies at subweekly resolution and inferred seasonal ecological patterns. Histologically controlled spatially resolved elemental analyses by laser-based plasma mass spectrometry confirmed the preservation of authentic biogenic signals despite the effect of spatially restricted diagenetic overprint. The Sr/Ca record of faunal remains is in line with expected trophic positions, contextualizing fossil hominid diet. Pongo sp. displays marked seasonal cycles with ~3 month-long strongly elevated Sr/Ca peaks, reflecting contrasting plant food consumption presumably during the monsoon season, while lower Sr/Ca ratios suggest different food availability during the dry season. In contrast, omnivorous H. erectus shows low and less accentuated intra-annual Sr/Ca variability compared to Pongo sp., with δ13C data of one individual indicating a dietary shift from C4 to a mix of C3 and C4 plants. Our data suggest that H. erectus on Java was maximizing the resources available in more open mosaic habitats and was less dependent on variations in seasonal resource availability. While still influenced by seasonal food availability, we infer that H. erectus was affected to a lesser degree than Pongo sp., which inhabited monsoonal rain forests on Java. We suggest that H. erectus maintained a greater degree of nutritional independence by exploiting the regional diversity of food resources across the seasons

Obesity and brain structure in schizophrenia - ENIGMA study in 3021 individuals

Schizophrenia is frequently associated with obesity, which is linked with neurostructural alterations. Yet, we do not understand how the brain correlates of obesity map onto the brain changes in schizophrenia. We obtained MRI-derived brain cortical and subcortical measures and body mass index (BMI) from 1260 individuals with schizophrenia and 1761 controls from 12 independent research sites within the ENIGMA-Schizophrenia Working Group. We jointly modeled the statistical effects of schizophrenia and BMI using mixed effects. BMI was additively associated with structure of many of the same brain regions as schizophrenia, but the cortical and subcortical alterations in schizophrenia were more widespread and pronounced. Both BMI and schizophrenia were primarily associated with changes in cortical thickness, with fewer correlates in surface area. While, BMI was negatively associated with cortical thickness, the significant associations between BMI and surface area or subcortical volumes were positive. Lastly, the brain correlates of obesity were replicated among large studies and closely resembled neurostructural changes in major depressive disorders. We confirmed widespread associations between BMI and brain structure in individuals with schizophrenia. People with both obesity and schizophrenia showed more pronounced brain alterations than people with only one of these conditions. Obesity appears to be a relevant factor which could account for heterogeneity of brain imaging findings and for differences in brain imaging outcomes among people with schizophrenia

Stable isotopes show Homo sapiens dispersed into cold steppes ~45,000 years ago at Ilsenhöhle in Ranis, Germany

The spread of Homo sapiens into new habitats across Eurasia ~45,000 years ago and the concurrent disappearance of Neanderthals represents a critical evolutionary turnover in our species' history. 'Transitional' technocomplexes, such as the Lincombian-Ranisian-Jerzmanowician (LRJ), characterize the European record during this period but their makers and evolutionary significance have long remained unclear. New evidence from Ilsenhöhle in Ranis, Germany, now provides a secure connection of the LRJ to H. sapiens remains dated to ~45,000 years ago, making it one of the earliest forays of our species to central Europe. Using many stable isotope records of climate produced from 16 serially sampled equid teeth spanning ~12,500 years of LRJ and Upper Palaeolithic human occupation at Ranis, we review the ability of early humans to adapt to different climate and habitat conditions. Results show that cold climates prevailed across LRJ occupations, with a temperature decrease culminating in a pronounced cold excursion at ~45,000-43,000 cal BP. Directly dated H. sapiens remains confirm that humans used the site even during this very cold phase. Together with recent evidence from the Initial Upper Palaeolithic, this demonstrates that humans operated in severe cold conditions during many distinct early dispersals into Europe and suggests pronounced adaptability. [Abstract copyright: © 2024. The Author(s).

DNA next generation sequencing to identify genetics abnormalities involved in developmental disorders with prenatal onset

Introduction : Les anomalies du développement (AD) sont caractérisées par une déficience intellectuelle (DI), un retard de croissance staturo-pondéral, une ou plusieurs malformation(s) congénitale(s) (MC), dont les particularités morphologiques faciales, qui peuvent-être identifiées avant la naissance. Elles compliquent environ 3% des naissances et sont responsables d’une morbi-mortalité majeure (20% des mort-nés, 10% de la mortalité néonatale et de 3 millions de handicap par an). Les AD sont majoritairement secondaires à des causes génétiques dont certaines sont associées à un risque de récurrence. En pratique clinique, les investigations conventionnelles conduisent à un diagnostic dans un tiers des cas. Le développement des techniques de séquençage nouvelle génération de l’ADN (NGS) est donc une opportunité pour élucider les bases moléculaires de ces pathologies rares et hétérogènes. Notre objectif était d’utiliser le NGS pour identifier les bases moléculaires de fœtus atteints de MC inexpliquées sur le plan moléculaire.Matériel et Méthodes : Nous avons utilisés deux approches différentes en fonction du phénotype fœtal : une approche pangénomique par séquençage d’exome (ES) pour les cas présentant un syndrome polymalformatif (cohorte « FOETEX ») et le séquençage ciblé pour les cas présentant des MC en mosaïque (cohorte « MOSAIQUE »). Au sein de la cohorte « FOETEX », nous avons réanalysé à partir des données anténatales les données d’ES solo pour lesquelles un variant de classe III à V avait été identifié par l’analyse après autopsie. Ensuite nous avons réalisé un ES en trio chez 30 cas pour lesquels l’ES solo après autopsie n’avait pas identifié de mutations pathogènes. Au sein de la cohorte « MOSAIQUE », nous avons réalisé un séquençage ciblé en profondeur des gènes de la voie PI3K-AKT-mTOR.Résultats : La réanalyse des données d’ES à partir des données anténatales a conduit au diagnostic dans 100% des cas (92% grâce à un ES en solo et 8% avec un ES en trio). Pour les 30 cas où nous avons réalisés un ES en trio, la réanalyse des données d’ES pour les gènes connus en pathologie humaine (OMIM) n’a pas identifié de variant de classe 4/5 et a identifié 2 variants de classe 3 (NXN, FRAS1). L’analyse étendue à l’ensemble de l’ES a permis d’identifier quatre gènes candidats robustes (WDR91, DNAH2, SEPT2 et PRPF19). 18 autres variations dans des gènes non rapportés en pathologie humaine ont été identifié. Le partage international de données n’a pas pu permettre de soutenir leur pathogénicité potentielle à l’heure actuelle (« absence de match » pour 4 cas et « match non-concluant » pour 14 cas). Le séquençage ciblé en profondeur a permis de conduire à un diagnostic dans 20/21 cas, avec une implication majoritaire des mutations pathogènes de PIK3CA, impliquées dans le spectre PROS.Conclusion : L’ES en trio semble être une technique performante pour identifier les bases moléculaires des MC, dès la période anténatale. Cependant de nombreuses limites du NGS, dont la plupart non spécifiques aux cas fœtaux, doivent encore être surmontées. L’accès aux tissus atteints semble être un des points clés des investigations moléculaires, à la fois pour les pathologies en mosaïque, mais également pour l’étude des variations transcriptomiques associées aux variations génomiques.Introduction: Developmental disorders (DD) are characterized by intellectual disability (ID), growth retardation, and at least one congenital malformation (CM), including dysmorphisms, which can be detected before birth. They affect about 3% of births and are associated with a high morbidity and mortality (20% of stillbirths, 10% of neonatal deaths and 3 million cases of disability per year). DD are mostly secondary to genetic abnormality, of which some are associated with a risk of recurrence. In clinical practice, conventional investigations lead to a diagnosis in only one third of cases. The development of DNA next generation sequencing (NGS) presents an opportunity to elucidate the molecular basis of these rare and heterogeneous disorders. Our aim was to use NGS to identify the molecular basis of fetuses with unexplained CM.Material and Methods: We used two different technologies depending on the fetal phenotype: exome sequencing (ES) for cases affected by multiple CM (FOETEX cohort) and ultra-deep targeted sequencing for cases affected by mosaicism (MOSAIC cohort). Within the FOETEX cohort, we blindly reanalyzed postmortem ES data using prenatal phenotype, only in fetuses harboring a (likely) pathogenic variant or a variant of unknown significance (by post-mortem analysis). Then, we performed a trio-ES in 30 cases with negative postmortem solo-ES. Within the "MOSAIC" cohort, we performed targeted ultra-deep sequencing of the PI3K-AKT-mTOR pathway genes.Results: Reanalysis of ES data using antenatal data led to a diagnosis in 100% of cases (92% with a solo-ES and 8% with a trio-ES). Regarding the 30 cases where we performed a trio ES, the reanalysis of ES data for genes known to be implicated in human pathology (OMIM) did not identify any class 4/5 variants and identified 2 class 3 variants (NXN, FRAS1). Further analysis of ES data identified four candidate genes (WDR91, DNAH2, SEPT2 and PRPF19). 18 other variations were identified in genes hitherto not associated with human pathology. Yet, their potential pathogenicity has not been identified according to international data sharing ("no match" for 4 cases and "inconclusive match" for the remaining 14). Targeted ultra-deep sequencing led to a diagnosis in 20 out of 21 cases, with a majority of pathogenic PIK3CA mutations, involved in the PROS spectrum.Conclusion: Trio-ES is a powerful tool to identify the molecular basis of CM. However, many limitations of NGS, most of which are not confined to fetal medicine, await resolution. Genetic tests on affected tissue may be performed to improve the diagnostic yield both for mosaic pathologies, as well as for the transcriptional study