Mantenimiento simultáneo del dimorfismo sexual y la condición hermafrodita en plantas. Un caso típico de selección negativa dependiente de la frecuencia

Las plantas con flor presentan sistemas de reproducción muy variados, con adaptaciones aparentes para su funcionamiento. No sorprende que hayan atraído el interés de los evolucionistas desde antiguo generando literatura de gran impacto, por ejemplo, en lo referente a la evitación de la endogamia. Sin embargo, en comparación con el equivalente animal, algunos aspectos sólo se han desarrollado parcial y recientemente, como la selección sexual, los conflictos de intereses reproductores, o la optimización del apareamiento. Hay un tipo de sistema de reproducción, el polimorfismo estilar, que ofrece buenas oportunidades para explorar hasta qué punto las plantas pueden controlar la pareja con la que se cruzan, o simplemente no necesitan pareja. Revisamos la evidencia disponible en un grupo de plantas (Narcissus) que muestran una amplia variedad de comportamientos. Algunas de las especies de este grupo de plantas han mostrado ser muy adecuadas para estudios de selección dependiente de la frecuencia, dada la presencia de morfos florales cuyo fitness depende de la frecuencia de cada morfo.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Demografía y cambio ambiental. Hipótesis para el cambio económico en el Cantábrico Oriental durante el Tardiglacial

El registro arqueozoológico disponible en los yacimientos del Cantábrico Oriental durante el Tardiglacial posee claras evidencias de la existencia de un cambio económico gradual desde posiciones especializadas a otras más diversificadas, en una tendencia progresiva de ampliación del nicho ecológico. No existe, sin embargo, un acuerdo general sobre las causas que motivaron esta evolución, pudiéndose distinguir las tesis demográficas, que abogan por un crecimiento sostenido de la población humana y sus necesidades energéticas como factor determinante, de las ambientales, que establecen la mejoría del clima y la reforestación como elementos precursores. En el presente trabajo se aborda esta cuestión a partir de la confección de un modelo matemático de simulación de la interacción entre los ciclos biológicos naturales de varios ungulados y las actividades de caza humana, estableciéndose finalmente la hipótesis demográfica como la más plausible de las dos.The zooarchaeological record available in Eastern Cantabrian sites during the Late Glacial shows clear evidences of a gradual economic change from specialized hunting strategies to more diversified ones, in a progressive trend towards an ecological niche enlargement. However, there is not a general agreement on the causes that triggered this evolution, with two main opposite points of view: a demographic theory, which proposes a continuous growth of human population and its energetic requirements as the determining factor, and an environmental one, which establishes the improvement of the climate and the reforestation as precursor elements. In this paper, the question is assessed by building a mathematical model that simulates the relationship between the biological cycle of some ungulates and the human hunting, finally establishing the demographic hypothesis as the most likely one

Aplicación de un sistema de información geográfica (SIG) al estudio arqueozoológico-tafonómico de la Cueva de La Fragua (Santoña, Cantabria). A GIS System for the archaeozoological and taphonomic study in the Cave of La Fragua (Santoña, Cantabria)

Dado el importante volumen de información arqueozoológica y tafonómica de un yacimiento como el de la Cueva de La Fragua y debido a la necesidad de proceder al estudio de su dispersión espacial, el uso de Sistemas informáticos de Información Geográfica ha permitido agilizar el proceso de análisis y disponer de una herramienta de gestión eficaz en la observación por niveles de la interacción de los restos óseos dentro del espacio arqueológico. En este trabajo se detalla el procedimiento utilizado y sus resultados.Given the great amount of archaeozoological and taphonomical information involved in a prehistoric deposit like La Fragua Cave and due to the need of interpreting its spatial dispersion, the use of Geographical Information Systems has allowed to speed up the analysis process and to manage an efficient tool on the observation of the relationship among bone remains in the archaeological space by levels. In this work it is explained the used procedure and its results

Dietary habits in the endangered Bearded Vulture Gypaetus barbatus from Upper Pleistocene to modern times in Spain: a paleobiological conservation perspective

Although most Old World vulture species are declining or threatened in Asia and Africa, in Europe healthy vulture populations still exist. However, recent application of sanitary legislation that has greatly reduced the availability of animal carcasses is now a concern for conservationists. Until now, no studies have been undertaken to determine long-term dietary shifts in these species in Europe, but such studies are essential to optimising the resources invested in conservation and to anticipating the ecological needs of the target species. Here, we present a first attempt to examine the dietary variation in the Bearded Vulture Gypaetus barbatus from the late Pleistocene to the present day. Medium-size wild ungulates such as southern chamois Rupicapra pyrenaica, Spanish ibex Capra pyrenaica, red deer Cervus elaphus and roe deer Capreolus capreolus dominate the diet during the Pleistocene supporting the hypothesis that Bearded Vulture distribution was largely determined by the presence of such species. On the contrary, domestic species, such as sheep Ovis aries and goat Capra hircus, are the most common taxa in the diet in modern and historic periods. The actual dependence of the species on livestock, along with a restrictive sanitary legislation, threaten the conservation of this and other endangered avian scavengers in Europe. This new paleobiological conservation perspective confirms that efforts to establish a self-sustaining Bearded Vulture population should be enhanced by the widespread availability of medium-sized wild ungulates and by the presence of extensive and traditional grazing practice

The Chronometric Dating and Subsistence of Late Neanderthals and Early Anatomically Modern Humans in the Central Balkans: Insights from Šalitrena Pecina (Mionica, Serbia)

ABSTRACT: Eastern Europe, particularly the Balkans, played a major role as a likely cul-de-sac for late Neanderthal survival and as a gateway to Europe for Anatomically Modern Humans (AMH) during the Middle to Upper Paleolithic transition. Despite the importance of the region, the known archaeological record during this period is still very limited, with little available site information. The recently excavated site of Šalitrena Pe?ina (Mionica, Serbia), south of the Danube River, contains archaeological evidence of late Mousterian, Aurignacian, and Gravettian occupations and presents an opportunity for understanding the behavior of both human populations in this eastern European region. Here we present the first radiocarbon dates for Neanderthal and AMH occupations in Serbia, as well as preliminary evidence on subsistence strategies obtained from the Mousterian and Aurignacian macrofaunal assemblages in Šalitrena Pe?ina. Radiocarbon dates indicate that Neanderthal and AMH groups may not have coexisted and interacted in this site. Nevertheless, zooarchaeological and taphonomic results show that both human populations were the main depositional agents of macrofaunal accumulation at the cave. The general compositions of the faunal assemblages reflect subtle differences between both human types and point to the necessity of further multidisciplinary research in southeastern Europe to increase our knowledge about human behavior and the causes of the demise of the Neanderthals in the Balkans.This research has been supported by a British Academy PDF (2011) and a Small Research Grant (SG102618) and by funds from the McDonald Institute for Archaeological Research in Cambridge during 2010/11. Currently, the research is involved in projects funded by the European Commission through FP7-PEOPLE-2012-CIG (Ref.N 322112) and by the Spanish Ministry of Economy and Competitiveness (HAR2012-33956). Since 2004, excavation in Šalitrena Pećina has been financed by the Ministry of Culture and Information of the Republic of Serbia

What Neanderthals and AMH ate: reassessment of the subsistence across the Middle–Upper Palaeolithic transition in the Vasco-Cantabrian region of SW Europe

Recent research in northern Spain has revealed the disappearance of Neanderthal populations in the Vasco Cantabrian region a few millennia earlier than in eastern and southern Iberia and discovered a short period of overlap with modern humans, at least, in terms of radiocarbon dates. However, the causes of Neanderthal decline understood as a regional and temporal process remain open. Despite the abundance of technological studies, modern?quality chronological dating, and the availability of archaeofaunal and palaeoenvironmental data, there is a lack of consensus about how climatic and environmental conditions could have affected ungulate prey and, therefore, Neanderthal subsistence strategies. In this paper, an analytical summary of the archaeofaunal and taphonomic data available for the Vasco?Cantabrian region, combined with the most recent chronological evidence, present general knowledge about animal biogeography and ecology during the Middle?Upper Palaeolithic transition, and provides an interpretation of the behaviour of both human species in the region. This work reviews the palaeomammal community of animals represented in the record as exploited by human groups in several caves and rock shelters and pointing to continuing lacunae in knowledge. Further research is needed to verify and potentially explain the apparent hominin population gap and the ultimate fate of the NeanderthalsThis research is funded by the European Research Council under the European Union's Horizon 2020 Research and Innovation Programme (grant agreement No. 818299‐ SUBSILIENCE project (https://www.subsilience.eu) and the Ministerio de Ciencia, Innovación y Universidades (ABRUPT ‐ HAR2017‐84997‐P) to ABMA. ASR's PhD is supported within the SUBSILIENCE project. The authors would like to thank J. García Sanchez (Instituto de Arqueología‐ Merida, CSIC‐Junta de Extramadura) for technical assistance with catchment areas analysis and Figs. 1, 5 and 6. Special thanks to L. Agudo (EvoAdapta‐University of Cantabria) for her technical assistance and G. Terlato for comments on the final version of the manuscript. The authors wish to acknowledge L. Straus for editing the manuscript and for his suggestions to improve this manuscript, as kind and effective as always

Darwin también era botánico

Reivindicación de la figura de Darwin como botánico, muchas veces ignorada por el público en general, además el autor llama la atención sobre la gran deuda que tienen todos los botánicos con e

Evidence of habitual behavior from non-alimentary dental wear on deciduous teeth from the Middle and Upper Paleolithic Cantabrian region, Northern Spain

The use of "teeth as tools" (non-masticatory or cultural-related dental wear) has largely been employed as a proxy for studying of past human behavior, mainly in permanent dentition from adult individuals. Here we present the analysis of the non-masticatory dental wear modifications on the deciduous dentition assigned to eight Neanderthal and anatomically modern human subadult individuals from Mousterian to Magdalenian technocultural contexts in the Cantabrian region (Northern Spain). Although preliminary, we tentatively suggest that these eight subadults present activity-related dental wear, including cultural striations, chipped enamel, toothpick grooves, and subvertical grooves. We also found evidence of habitual dental hygienic practices in the form of toothpicking on a deciduous premolar. Orientation of the cultural striations indicates similar handedness development as in modern children. Taken together, these dental wear patterns support the participation of young individuals in group activities, making them potential contributors to group welfare. This study potentially adds new evidence to the importance of the use of the mouth in paramasticatory activities or as a third hand throughout the Pleistocene, which can be confirmed with a more specific reference sample.We thank the curators at the following museums for providing access to the collections: Museo de Arqueología de Asturias (Las Caldas and Tito Bustillo), Museo de Prehistoria y Arqueología de Cantabria (El Castillo) and Arkeologi Museoa (Santa Catalina and Axlor).We are very grateful to the Editors-in-Chief (David Alba and Clément Zanolli), the Associate Editor, and reviewers for their comments and suggestions, which greatly improved the quality of this paper. A.E. was beneficiary of a Juan de la Cierva-Formaci on Postdoctoral Fellowship (grant number FJCI-2016-30122). Partial aspects of this research have been founded by SUBSILIENCE ERCProject (ERCEA-; grant agreement No. 818299), ABRUPT project (HAR2017-84997-P Spanish Ministry of Science, Innovation and Universities) and Santander Bank within the program of Santander Talent Attraction for Research (STAR1) to A.B.M.A., and H2020- MSCA-IF project No. 891529 (3DFOSSILDIET) to A.E

Bee and floral traits affect the characteristics of the vibrations experienced by flowers during buzz pollination

During buzz pollination, bees use their indirect flight muscles to produce vibrations that are transmitted to the flowers and result in pollen release. Although buzz pollination has been known for >100 years, we are still in the early stages of understanding how bee and floral characteristics affect the production and transmission of floral vibrations. Here, we analysed floral vibrations produced by four closely related bumblebee taxa (Bombus spp.) on two buzz-pollinated plants species (Solanum spp.). We measured floral vibrations transmitted to the flower to establish the extent to which the mechanical properties of floral vibrations depend on bee and plant characteristics. By comparing four bee taxa visiting the same plant species, we found that peak acceleration, root mean-squared acceleration (RMS) and frequency vary between bee taxa, but that neither bee size (intertegular distance) nor flower biomass (dry mass) affects peak acceleration, RMS or frequency. A comparison of floral vibrations of two bee taxa visiting flowers of two plant species showed that, while bee species affects peak acceleration, RMS and frequency, plant species only affects acceleration (peak acceleration and RMS), not frequency. When accounting for differences in the transmission of vibrations across the two types of flower, using a species-specific ‘coupling factor’, we found that RMS acceleration and peak displacement do not differ between plant species. This suggests that bees produce the same initial acceleration in different plants but that transmission of these vibrations through the flower is affected by floral characteristics