Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 49
Filtrar
Más filtros

Bases de datos
Tipo del documento
Intervalo de año de publicación
1.
Conserv Biol ; 37(1): e13965, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-35686511

RESUMEN

Ladybirds (Coleoptera: Coccinellidae) provide services that are critical to food production, and they fulfill an ecological role as a food source for predators. The richness, abundance, and distribution of ladybirds, however, are compromised by many anthropogenic threats. Meanwhile, a lack of knowledge of the conservation status of most species and the factors driving their population dynamics hinders the development and implementation of conservation strategies for ladybirds. We conducted a review of the literature on the ecology, diversity, and conservation of ladybirds to identify their key ecological threats. Ladybird populations are most affected by climate factors, landscape composition, and biological invasions. We suggest mitigating actions for ladybird conservation and recovery. Short-term actions include citizen science programs and education, protective measures for habitat recovery and threatened species, prevention of the introduction of non-native species, and the maintenance and restoration of natural areas and landscape heterogeneity. Mid-term actions involve the analysis of data from monitoring programs and insect collections to disentangle the effect of different threats to ladybird populations, understand habitat use by taxa on which there is limited knowledge, and quantify temporal trends of abundance, diversity, and biomass along a management-intensity gradient. Long-term actions include the development of a worldwide monitoring program based on standardized sampling to fill data gaps, increase explanatory power, streamline analyses, and facilitate global collaborations.


Las catarinas (Coleoptera: Coccinellidae) proporcionan servicios que son críticos para la producción de alimento, y juegan un papel ecológico como fuente de alimento para depredadores. Sin embargo, la riqueza, abundancia y distribución de catarinas están en peligro debido a muchas amenazas antropogénicas. La carencia de conocimiento sobre el estatus de conservación de la mayoría de las especies y los factores que inciden en su dinámica poblacional dificulta el desarrollo e implementación de estrategias de conservación para las catarinas. Realizamos una revisión de la literatura sobre la ecología, diversidad y conservación de catarinas para identificar sus amenazas ecológicas clave. Las poblaciones de catarinas fueron afectadas mayormente por factores climáticos, composición del paisaje e invasiones biológicas. Proponemos acciones de mitigación para la conservación y recuperación de catarinas. Acciones a corto plazo incluyen programas de ciencia y educación ciudadana, medidas de protección para la recuperación de hábitat y de especies amenazadas, prevención de la introducción de especies no nativas y el mantenimiento y restauración de áreas naturales y la heterogeneidad del paisaje. Acciones a mediano plazo implican el análisis de datos obtenidos de programas de monitoreo y colecciones de insectos para desenmarañar el efecto de las diferentes amenazas a las poblaciones de catarinas, comprender el uso del hábitat por taxa de los que se tiene conocimiento limitado y cuantifica las tendencias temporales de la abundancia, diversidad y biomasa a lo largo de un gradiente de intensidad de manejo. Acciones a largo plazo incluyen el desarrollo de un programa de monitoreo a nivel mundial basado en muestreos estandarizados para subsanar la falta de datos, incrementar el poder explicativo, optimizar los análisis y facilitar colaboraciones globales.


Asunto(s)
Conservación de los Recursos Naturales , Ecosistema , Animales , Especies en Peligro de Extinción , Dinámica Poblacional
2.
Glob Chang Biol ; 28(13): 3998-4012, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35535680

RESUMEN

Recent climate and land-use changes are having substantial impacts on biodiversity, including population declines, range shifts, and changes in community composition. However, few studies have compared these impacts among multiple taxa, particularly because of a lack of standardized time series data over long periods. Existing data sets are typically of low resolution or poor coverage, both spatially and temporally, thereby limiting the inferences that can be drawn from such studies. Here, we compare climate and land-use driven occupancy changes in butterflies, grasshoppers, and dragonflies using an extensive data set of highly heterogeneous observation data collected in the central European region of Bavaria (Germany) over a 40-year period. Using occupancy models, we find occupancies (the proportion of sites occupied by a species in each year) of 37% of species have decreased, 30% have increased and 33% showed no significant trend. Butterflies and grasshoppers show strongest declines with 41% of species each. By contrast, 52% of dragonfly species increased. Temperature preference and habitat specificity appear as significant drivers of species trends. We show that cold-adapted species across all taxa have declined, whereas warm-adapted species have increased. In butterflies, habitat specialists have decreased, while generalists increased or remained stable. The trends of habitat generalists and specialists both in grasshoppers and semi-aquatic dragonflies, however did not differ. Our findings indicate strong and consistent effects of climate warming across insect taxa. The decrease of butterfly specialists could hint towards a threat from land-use change, as especially butterfly specialists' occurrence depends mostly on habitat quality and area. Our study not only illustrates how these taxa showed differing trends in the past but also provides hints on how we might mitigate the detrimental effects of human development on their diversity in the future.


Asunto(s)
Mariposas Diurnas , Odonata , Animales , Biodiversidad , Clima , Cambio Climático , Ecosistema , Europa (Continente)
3.
Conserv Biol ; 35(2): 502-509, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-32656858

RESUMEN

Measuring progress toward international biodiversity targets requires robust information on the conservation status of species, which the International Union for Conservation of Nature (IUCN) Red List of Threatened Species provides. However, data and capacity are lacking for most hyperdiverse groups, such as invertebrates, plants, and fungi, particularly in megadiverse or high-endemism regions. Conservation policies and biodiversity strategies aimed at halting biodiversity loss by 2020 need to be adapted to tackle these information shortfalls after 2020. We devised an 8-point strategy to close existing data gaps by reviving explorative field research on the distribution, abundance, and ecology of species; linking taxonomic research more closely with conservation; improving global biodiversity databases by making the submission of spatially explicit data mandatory for scientific publications; developing a global spatial database on threats to biodiversity to facilitate IUCN Red List assessments; automating preassessments by integrating distribution data and spatial threat data; building capacity in taxonomy, ecology, and biodiversity monitoring in countries with high species richness or endemism; creating species monitoring programs for lesser-known taxa; and developing sufficient funding mechanisms to reduce reliance on voluntary efforts. Implementing these strategies in the post-2020 biodiversity framework will help to overcome the lack of capacity and data regarding the conservation status of biodiversity. This will require a collaborative effort among scientists, policy makers, and conservation practitioners.


Una Estrategia para la Siguiente Década para Enfrentar la Deficiencia de Datos de la Biodiversidad Ignorada Resumen La medida del avance hacia los objetivos internacionales para la biodiversidad requiere información sólida sobre el estado de conservación de las especies, la cual proporciona la Lista Roja de Especies Amenazadas de la Unión Internacional para la Conservación de la Naturaleza (UICN). Sin embargo, los grupos más hiperdiversos, como los invertebrados, las plantas y los hongos, carecen de datos y capacidad, particularmente en regiones megadiversas o de endemismo alto. Las políticas de conservación y las estrategias de biodiversidad dirigidas hacia el cese de la pérdida de biodiversidad para el 2020 necesitan ser adaptadas para solucionar estas insuficiencias de información para después del año 2020. Diseñamos una estrategia de ocho puntos para cerrar las brechas existentes en los datos mediante la reactivación de la investigación exploratoria en el campo sobre la distribución, abundancia y ecología de las especies; la vinculación más cercana entre la investigación taxonómica y la conservación; la mejora a las bases de datos mundiales sobre biodiversidad mediante la presentación obligatoria de datos espacialmente explícitos para las publicaciones científicas; el desarrollo de una base mundial de datos espaciales sobre las amenazas para la biodiversidad para facilitar las valoraciones de la Lista Roja de la UICN; la automatización de las preevaluaciones mediante la integración de datos de distribución y datos de amenazas espaciales; el desarrollo de la capacidad en la taxonomía, la ecología y el monitoreo de la biodiversidad en países con una gran riqueza de especies o endemismos; la creación de programas de monitoreo de especies para los taxones menos conocidos; el desarrollo de suficientes mecanismos de financiamiento para reducir la dependencia de los esfuerzos voluntarios. La implementación de estas estrategias en el marco de trabajo para la biodiversidad posterior al 2020 ayudará a superar la falta de capacidad y datos con respecto al estado de conservación de la biodiversidad. Lo anterior requerirá de un esfuerzo colaborativo entre científicos, formuladores de políticas y practicantes de la conservación.


Asunto(s)
Biodiversidad , Conservación de los Recursos Naturales , Animales , Ecología , Especies en Peligro de Extinción , Plantas
4.
Conserv Biol ; 35(5): 1388-1395, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-33484006

RESUMEN

Some conservation prioritization methods are based on the assumption that conservation needs overwhelm current resources and not all species can be conserved; therefore, a conservation triage scheme (i.e., when the system is overwhelmed, species should be divided into three groups based on likelihood of survival, and efforts should be focused on those species in the group with the best survival prospects and reduced or denied to those in the group with no survival prospects and to those in the group not needing special efforts for their conservation) is necessary to guide resource allocation. We argue that this decision-making strategy is not appropriate because resources are not as limited as often assumed, and it is not evident that there are species that cannot be conserved. Small population size alone, for example, does not doom a species to extinction; plants, reptiles, birds, and mammals offer examples. Although resources dedicated to conserving all threatened species are insufficient at present, the world's economic resources are vast, and greater resources could be dedicated toward species conservation. The political framework for species conservation has improved, with initiatives such as the UN Sustainable Development Goals and other international agreements, funding mechanisms such as The Global Environment Facility, and the rise of many nongovernmental organizations with nimble, rapid-response small grants programs. For a prioritization system to allow no extinctions, zero extinctions must be an explicit goal of the system. Extinction is not inevitable, and should not be acceptable. A goal of no human-induced extinctions is imperative given the irreversibility of species loss.


Asignación de Recursos para la Conservación, Resiliencia de Poblaciones Pequeñas y la Falacia del Triaje de Conservación Resumen Algunos métodos de priorización de la conservación están basados en el supuesto de que las necesidades de la conservación superan a los actuales recursos y que no todas las especies pueden ser conservadas; por lo tanto, se necesita un esquema de triaje (esto es, cuando el sistema está abrumado, las especies deben dividirse en tres grupos con base en su probabilidad de supervivencia y los esfuerzos deben enfocarse en aquellas especies dentro del grupo con las mejores probabilidades de supervivencia y a aquellas en el grupo sin probabilidades de supervivencia o aquellas en el grupo que no necesita esfuerzos especializados para su conservación se les deben reducir o negar los esfuerzos de conservación) para dirigir la asignación de recursos. Discutimos que esta estrategia para la toma de decisiones no es apropiada porque los recursos no están tan limitados como se asume con frecuencia y tampoco es evidente que existan especies que no puedan ser conservadas. Por ejemplo, tan sólo un tamaño poblacional pequeño no es suficiente para condenar a una especie a la extinción; contamos con ejemplos en plantas, reptiles, aves y mamíferos. Aunque actualmente todos los recursos dedicados a la conservación de todas las especies amenazadas son insuficientes, los recursos económicos mundiales son vastos y se podrían dedicar mayores recursos a la conservación de especies. El marco de trabajo político para la conservación de especies ha mejorado, con iniciativas como los Objetivos de Desarrollo Sustentable de la ONU y otros acuerdos internacionales, el financiamiento de mecanismos como el Fondo para el Medio Ambiente Mundial, y el surgimiento de muchas organizaciones no gubernamentales mediante programas de subsidios pequeños hábiles y de respuesta rápida. Para que un sistema de priorización no permita las extinciones, las cero extinciones deben ser un objetivo explícito del sistema. La extinción no es inevitable y no debería ser aceptable. El objetivo de cero extinciones inducidas por humanos es imperativo dada la irreversibilidad de la pérdida de especies.


Asunto(s)
Conservación de los Recursos Naturales , Triaje , Animales , Biodiversidad , Especies en Peligro de Extinción , Extinción Biológica , Mamíferos , Asignación de Recursos
5.
Conserv Biol ; 35(6): 1833-1849, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34289517

RESUMEN

Recognizing the imperative to evaluate species recovery and conservation impact, in 2012 the International Union for Conservation of Nature (IUCN) called for development of a "Green List of Species" (now the IUCN Green Status of Species). A draft Green Status framework for assessing species' progress toward recovery, published in 2018, proposed 2 separate but interlinked components: a standardized method (i.e., measurement against benchmarks of species' viability, functionality, and preimpact distribution) to determine current species recovery status (herein species recovery score) and application of that method to estimate past and potential future impacts of conservation based on 4 metrics (conservation legacy, conservation dependence, conservation gain, and recovery potential). We tested the framework with 181 species representing diverse taxa, life histories, biomes, and IUCN Red List categories (extinction risk). Based on the observed distribution of species' recovery scores, we propose the following species recovery categories: fully recovered, slightly depleted, moderately depleted, largely depleted, critically depleted, extinct in the wild, and indeterminate. Fifty-nine percent of tested species were considered largely or critically depleted. Although there was a negative relationship between extinction risk and species recovery score, variation was considerable. Some species in lower risk categories were assessed as farther from recovery than those at higher risk. This emphasizes that species recovery is conceptually different from extinction risk and reinforces the utility of the IUCN Green Status of Species to more fully understand species conservation status. Although extinction risk did not predict conservation legacy, conservation dependence, or conservation gain, it was positively correlated with recovery potential. Only 1.7% of tested species were categorized as zero across all 4 of these conservation impact metrics, indicating that conservation has, or will, play a role in improving or maintaining species status for the vast majority of these species. Based on our results, we devised an updated assessment framework that introduces the option of using a dynamic baseline to assess future impacts of conservation over the short term to avoid misleading results which were generated in a small number of cases, and redefines short term as 10 years to better align with conservation planning. These changes are reflected in the IUCN Green Status of Species Standard.


RESUMEN: Reconociendo que era imperativo evaluar la recuperación de especies y el impacto de la conservación, la Unión Internacional para la Conservación de la Naturaleza (UICN) convocó en 2012 al desarrollo de una "Lista Verde de Especies" (ahora el Estatus Verde de las Especies de la UICN). Un marco de referencia preliminar de una Lista Verde de Especies para evaluar el progreso de las especies hacia la recuperación, publicado en 2018, proponía 2 componentes separados pero interconectados: un método estandarizado (i.e., medición en relación con puntos de referencia de la viabilidad de especies, funcionalidad y distribución antes del impacto) para determinar el estatus de recuperación actual (puntuación de recuperación de la especie) y la aplicación de ese método para estimar impactos en el pasado y potenciales de conservación basados en 4 medidas (legado de conservación, dependencia de conservación, ganancia de conservación y potencial de recuperación). Probamos el marco de referencia con 181 especies representantes de diversos taxa, historias de vida, biomas, y categorías (riesgo de extinción) en la Lista Roja de la IUCN. Con base en la distribución observada de la puntuación de recuperación de las especies, proponemos las siguientes categorías de recuperación de la especie: totalmente recuperada, ligeramente mermada, moderadamente mermada, mayormente mermada, gravemente mermada, extinta en estado silvestre, e inderterminada. Cincuenta y nueve por ciento de las especies se consideraron mayormente o gravemente mermada. Aunque hubo una relación negativa entre el riesgo de extinción y la puntuación de recuperación de la especie, la variación fue considerable. Algunas especies en las categorías de riesgo bajas fueron evaluadas como más lejos de recuperarse que aquellas con alto riesgo. Esto enfatiza que la recuperación de especies es diferente conceptualmente al riesgo de extinción y refuerza la utilidad del Estado Verde de las Especies de la UICN para comprender integralmente el estatus de conservación de especies. Aunque el riesgo de extinción no predijo el legado de conservación, la dependencia de conservación o la ganancia de conservación, se correlacionó positivamente con la potencial de recuperación. Solo 1.7% de las especies probadas fue categorizado como cero en los 4 indicadores de impacto de la conservación, lo que indica que la conservación ha jugado, o jugará, un papel en la mejoría o mantenimiento del estatus de la especie la gran mayoría de ellas. Con base en nuestros resultados, diseñamos una versión actualizada del marco de referencia para la evaluación que introduce la opción de utilizar una línea de base dinámica para evaluar los impactos futuros de la conservación en el corto plazo y redefine corto plazo como 10 años.


Asunto(s)
Especies en Peligro de Extinción , Extinción Biológica , Animales , Biodiversidad , Conservación de los Recursos Naturales , Ecosistema , Riesgo
6.
Conserv Biol ; 34(3): 743-753, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-31825105

RESUMEN

Information on population sizes and trends of threatened species is essential for their conservation, but obtaining reliable estimates can be challenging. We devised a method to improve the precision of estimates of population size obtained from capture-recapture studies for species with low capture and recapture probabilities and short seasonal activity, illustrated with population data of an elusive grasshopper (Prionotropis rhodanica). We used data from 5 capture-recapture studies to identify methodological and environmental factors affecting capture and recapture probabilities and estimates of population size. In a simulation, we used the population size and capture and recapture probability estimates obtained from the field studies to identify the minimum number of sampling occasions needed to obtain unbiased and robust estimates of population size. Based on these results we optimized the capture-recapture design, implemented it in 2 additional studies, and compared their precision with those of the nonoptimized studies. Additionally, we simulated scenarios based on thresholds of population size in criteria C and D of the International Union for Conservation of Nature (IUCN) Red List to investigate whether estimates of population size for elusive species can reliably inform red-list assessments. Identifying parameters that affect capture and recapture probabilities (for the grasshopper time since emergence of first adults) and optimizing field protocols based on this information reduced study effort (-6% to -27% sampling occasions) and provided more precise estimates of population size (reduced coefficient of variation) compared with nonoptimized studies. Estimates of population size from the scenarios based on the IUCN thresholds were mostly unbiased and robust (only the combination of very small populations and little study effort produced unreliable estimates), suggesting capture-recapture can be considered reliable for informing red-list assessments. Although capture-recapture remains difficult and costly for elusive species, our optimization procedure can help determine efficient protocols to increase data quality and minimize monitoring effort.


Optimización del Monitoreo de Captura y Recaptura de Especies Esquivas Ilustrado con un Saltamontes Amenazado Resumen La información sobre los tamaños poblacionales y las tendencias de las especies amenazadas es esencial para su conservación, pero la obtención de estimaciones confiables puede ser todo un reto. Diseñamos un método para mejorar la precisión de las estimaciones del tamaño poblacional obtenidos de estudios de captura y recaptura para especies con probabilidades bajas de captura y recaptura y una corta actividad estacional y lo ilustramos con los datos poblacionales de un saltamontes esquivo (Prionotropis rhodanica). Usamos los datos de cinco estudios de captura y recaptura para identificar los factores metodológicos y ambientales que afectan a la probabilidad de captura y recaptura y a los estimados de tamaños poblacionales. En una simulación, usamos el tamaño poblacional y las estimaciones de probabilidad de captura y recaptura obtenidos en estudios de campo para identificar el número mínimo de ocasiones de muestreo necesarias para obtener estimaciones imparciales y sólidos del tamaño poblacional. Con base en estos resultados, optimizamos el diseño de la captura y recaptura, la implementamos en dos estudios adicionales y comparamos su precisión con aquella de los estudios no optimizados. Además, simulamos escenarios con base en los umbrales de tamaño poblacional localizados en los criterios C y D de la Lista Roja de la Unión Internacional para la Conservación de la Naturaleza (UICN) para conocer si las estimaciones del tamaño poblacional para especies esquivas pueden informar certeramente las valoraciones de lista roja. La identificación de los parámetros que afectan las probabilidades de captura y recaptura (desde el momento de aparición de los primeros saltamontes adultos) y la optimización de los protocolos de campo con base en esta información redujeron el esfuerzo de estudio (−6% a −27% ocasiones de muestreo) y proporcionaron estimaciones más precisas del tamaño poblacional (coeficiente reducido de variación) en comparación con los estudios no optimizados. Las estimaciones del tamaño poblacional tomadas de los escenarios basados en los umbrales de la UICN fueron, en su mayoría, imparciales y sólidos (sólo la combinación de poblaciones muy pequeñas y un esfuerzo mínimo de estudio produjo estimaciones no confiables), lo que sugiere que la captura y recaptura puede considerarse como confiable para informar las valoraciones de lista roja. Aunque la captura y recaptura todavía es complicada y costosa cuando se aplica a especies esquivas, ésta puede ayudar a determinar los protocolos eficientes para incrementar la calidad de los datos y minimizar el esfuerzo de monitoreo.


Asunto(s)
Conservación de los Recursos Naturales , Saltamontes , Animales , Ecosistema , Especies en Peligro de Extinción , Densidad de Población
7.
Mol Ecol ; 28(17): 3848-3856, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31392753

RESUMEN

Conservation genetics is a well-established scientific field. However, limited information transfer between science and practice continues to hamper successful implementation of scientific knowledge in conservation practice and management. To mitigate this challenge, we have established a conservation genetics community, which entails an international exchange-and-skills platform related to genetic methods and approaches in conservation management. First, it allows for scientific exchange between researchers during annual conferences. Second, personal contact between conservation professionals and scientists is fostered by organising workshops and by popularising knowledge on conservation genetics methods and approaches in professional journals in national languages. Third, basic information on conservation genetics has been made accessible by publishing an easy-to-read handbook on conservation genetics for practitioners. Fourth, joint projects enabled practitioners and scientists to work closely together from the start of a project in order to establish a tight link between applied questions and scientific background. Fifth, standardised workflows simplifying the implementation of genetic tools in conservation management have been developed. By establishing common language and trust between scientists and practitioners, all these measures help conservation genetics to play a more prominent role in future conservation planning and management.


Asunto(s)
Conservación de los Recursos Naturales , Fenómenos Genéticos , Animales , Ecosistema , Ciencia
8.
Proc Biol Sci ; 285(1883)2018 07 25.
Artículo en Inglés | MEDLINE | ID: mdl-30051861

RESUMEN

Introductions of non-native lineages increase opportunities for hybridization. Non-native lineages of the common wall lizard, Podarcis muralis, are frequently introduced in cities where they hybridize with native populations. We aimed at unravelling the invasion history and admixture of native and non-native wall lizards in four German cities using citywide, comprehensive sampling. We barcoded and genotyped 826 lizards and tested if gene flow in populations composed of admixed native and introduced lineages is facilitated by similar environmental factors to those in native populations by comparing fine-scale landscape genetic patterns. In cities with non-native lineages, lizards commonly occurred in numerous clusters of hybrid swarms, which showed variable lineage composition, consisting of up to four distinct evolutionary lineages. Hybrid swarms held vast genetic diversity and showed recent admixture with other hybrid swarms. Landscape genetic analyses showed differential effects of cityscape structures across cities, but identified water bodies as strong barriers to gene flow in both native and admixed populations. By contrast, railway tracks facilitated gene flow of admixed populations only. Our study shows that cities represent unique settings for hybridization, caused by multiple introductions of non-native taxa. Cityscape structure and invasion histories of cities will determine future evolutionary pathways at these novel hybrid zones.


Asunto(s)
Entorno Construido , Flujo Génico , Hibridación Genética , Lagartos/genética , Animales , Ciudades , Alemania , Dinámica Poblacional
9.
Mol Phylogenet Evol ; 121: 98-109, 2018 04.
Artículo en Inglés | MEDLINE | ID: mdl-29330138

RESUMEN

Amphibians have a complex reproductive behaviour, which shows the highest diversity among tetrapodes. The family Salamandridae, distributed across the entire Holarctic, is one of the most diverse groups of extant salamanders comprising 114 species in 21 genera. The family has a remarkable diversity of courtship modes, amplexus and sperm transfer. It is often hypothesised that this diversity has evolved in adaptation to a specific mating and/or breeding habitat. We test this hypothesis based upon a phylogenetic reconstruction using the complete mitochondrial genome sequences of 45 Salamandridae species, representing all existing genera. We used ancestral character state reconstruction methods and geographic range models and applied relaxed Bayesian molecular clock models to discuss the results in a temporal framework of Salamandridae evolution. Our results show that the family Salamandridae started to diversify in the Late Cretaceous (ca. 87 mya) and is of Western Palearctic origin. Ancestral character state reconstruction predicts that its common ancestor was oviparous, mated on land without amplexus and probably showed a pin wheel spermatophore transfer, which is still found in the Italian endemic Salamandrina terdigidata. Our results suggest that several colonization of continents with subsequent radiations took place, once to the Nearctic and twice into Eastern Asian realms. However, these events were only in one case associated with a change in mating behaviour (dorsal amplexus in Nearctic newts). Around the Cretaceous-Paleogene boundary (K-Pg boundary) several Salamandridae lineages further diverged, again with no obvious changes in mating behaviour. Overall, there is no significant signal for mating character evolution being caused by changes in habitat type, with only a slight tendency that changes in mating habitat might have led to changes in the type of sperm transfer which in turn was associated with changes in the presence or absence of amplexus.


Asunto(s)
Evolución Biológica , Ecosistema , Filogeografía , Salamandridae/fisiología , Conducta Sexual Animal , Animales , Teorema de Bayes , Filogenia , Salamandridae/clasificación , Especificidad de la Especie , Factores de Tiempo
10.
Mol Phylogenet Evol ; 118: 318-329, 2018 01.
Artículo en Inglés | MEDLINE | ID: mdl-28986236

RESUMEN

Vicariance and dispersal are two important processes shaping biodiversity patterns. The South African Cape Floristic Region (CFR) is known for its high biotic diversity and endemism. However, studies on the phylogeography of endemic invertebrates in this biodiversity hotspot are still scarce. Here, we present a phylogenetic study of the flightless grasshopper genus Betiscoides, which is endemic to the CFR and strongly associated with restio plants (Restionaceae). We hypothesized that the genus originated in the southwestern part of the CFR, that differentiation within the genus is mainly an effect of vicariance and that the three known species only represent a minor fraction of the real genetic diversity of the genus. We inferred the phylogeny based on sequences of three mitochondrial and two nuclear genes from 99 Betiscoides specimens collected across the CFR. Furthermore, we conducted a SDIVA analysis to detect distributions of ancestral nodes and the possible spatial origin of these lineages. Strong differentiation among genetic lineages was shown. The ancestor of this genus was most likely distributed in the southwestern CFR. Five major lineages were detected, three of which were ancestrally distributed in the southwestern CFR. The ancestors of the two other lineages were distributed in the northern and eastern margins of the CFR. A total of 24 divergent evolutionary lineages were found, reflecting the geographical isolation of restio-dominated fynbos habitats. Dispersal played a more prominent role than expected in differentiation of Betiscoides. While the five main lineages were separated during a first phase via dispersal, differentiation occurred later and on smaller spatial scale, predominantly driven by isolation in montane refugia (i.e. vicariance). Our study also suggests that flightless insect taxa likely show high levels of differentiation in biodiversity hotspots with their taxonomy often being incomplete.


Asunto(s)
Saltamontes/clasificación , Animales , Secuencia de Bases , Teorema de Bayes , Evolución Biológica , ADN/química , ADN/aislamiento & purificación , ADN/metabolismo , Variación Genética , Saltamontes/genética , Mitocondrias/genética , Filogenia , Filogeografía , Alineación de Secuencia , Análisis de Secuencia de ADN , Sudáfrica
11.
Nature ; 547(7664): 403, 2017 07 26.
Artículo en Inglés | MEDLINE | ID: mdl-28748937
14.
Mol Ecol ; 25(20): 4984-5000, 2016 10.
Artículo en Inglés | MEDLINE | ID: mdl-27543765

RESUMEN

Functional connectivity is essential for the long-term persistence of populations. However, many studies assess connectivity with a focus on structural connectivity only. Cityscapes, namely urban landscapes, are particularly dynamic and include numerous potential anthropogenic barriers to animal movements, such as roads, traffic or buildings. To assess and compare structural connectivity of habitats and functional connectivity of gene flow of an urban lizard, we here combined species distribution models (SDMs) with an individual-based landscape genetic optimization procedure. The most important environmental factors of the SDMs are structural diversity and substrate type, with high and medium levels of structural diversity as well as open and rocky/gravel substrates contributing most to structural connectivity. By contrast, water cover was the best model of all environmental factors following landscape genetic optimization. The river is thus a major barrier to gene flow, while of the typical anthropogenic factors only buildings showed an effect. Nonetheless, using SDMs as a basis for landscape genetic optimization provided the highest ranked model for functional connectivity. Optimizing SDMs in this way can provide a sound basis for models of gene flow of the cityscape, and elsewhere, while presence-only and presence-absence modelling approaches showed differences in performance. Additionally, interpretation of results based on SDM factor importance can be misleading, dictating more thorough analyses following optimization of SDMs. Such approaches can be adopted for management strategies, for example aiming to connect native common wall lizard populations or disconnect them from non-native introduced populations, which are currently spreading in many cities in Central Europe.


Asunto(s)
Ecosistema , Flujo Génico , Genética de Población , Lagartos/genética , Distribución Animal , Animales , Ciudades , Conservación de los Recursos Naturales , Genotipo , Alemania , Repeticiones de Microsatélite , Modelos Genéticos , Dinámica Poblacional , Ríos
15.
J Hered ; 107(4): 363-6, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-26946287

RESUMEN

The Northern Bald Ibis is one of the rarest bird species, extinct in Europe for 400 years and critically endangered worldwide. The European Union-co-financed LIFE+ project "Reason for Hope - Reintroduction of the Northern Bald Ibis in Europe" aims to reintroduce the species in Europe (Germany, Austria, Italy). In order to obtain information on the genetic diversity within zoo colonies and the reintroduced population, 15 polymorphic microsatellite markers, specific for the Northern Bald Ibis, Geronticus eremita (Linnaeus, 1785), have been isolated from next-generation sequencing (Illumina MiSeq) and are described here. The microsatellite primers were tested in 30 individuals and measures of genetic variability were calculated. Values for the observed heterozygosity ranged from 0.393 to 0.867, while expected heterozygosity ranged from 0.573 to 0.718. Ten out of 15 loci were in Hardy-Weinberg equilibrium and only one showed indication for the presence of null alleles. The newly developed PCR primers can be used to examine population genetic parameters, e.g. for future conservation genetic studies of this critically endangered bird species.


Asunto(s)
Aves/genética , Especies en Peligro de Extinción , Secuenciación de Nucleótidos de Alto Rendimiento , Repeticiones de Microsatélite , Alelos , Animales , Genética de Población , Polimorfismo Genético
16.
Hereditas ; 153: 1, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-28096763

RESUMEN

BACKGROUND: The grasshopper family Lentulidae is endemic to eastern and southern Africa, with its center of diversity situated in South Africa, the highest diversity being found in the Cape Floristic Region, which is one of the global biodiversity hotspots. The family consists of 35 genera sorted in two subfamilies. This study provides first insights into the phylogeny of Lentulidae. Two mitochondrial genes (12S and NDS) were sequenced and the phylogeny was inferred through Maximum Likelihood and Bayesian Inference. RESULTS: Our results indicate that the current classification into the subfamilies Lentulinae and Shelforditinae may be incorrect as Uvarovidium, Leatettix (Shelforditinae) and Devylderia (Lentulinae) clustered together in one main clade, while Betiscoides, Basutacris and Gymnidium (all Lentulinae) formed the second main clade. The genera Uvarovidium and Leatettix, which had been assigned to the Acrididae (subfamily Hemiacridinae) in the past, grouped within the Lentulidae, confirming their current assignment to this family. The East African Usambilla group is likely to represent a sister clade to the south African Lentula and Eremidium. Diversification patterns in the genus Devylderia and Betiscoides suggest a higher number of species than currently known. CONCLUSIONS: Our phylogeny is not in line with the current systematics of Lentulidae, suggesting that a broader sampling and a study of the genitalia would be useful to clarify the taxonomy. Furthermore, some genera (particularly Betiscoides and Devylderia) are in need of taxonomic revision, as the number of species within these genera is likely to be higher than the current taxonomy suggests.


Asunto(s)
Ortópteros/clasificación , Filogenia , Animales , Teorema de Bayes , ADN Mitocondrial/genética , Evolución Molecular , Genes Mitocondriales , Funciones de Verosimilitud , Ortópteros/genética , Análisis de Secuencia de ADN , Sudáfrica
17.
BMC Evol Biol ; 15: 191, 2015 Sep 16.
Artículo en Inglés | MEDLINE | ID: mdl-26376739

RESUMEN

BACKGROUND: Hybridization between species is of conservation concern as it might threaten the genetic integrity of species. Anthropogenic factors can alter hybridization dynamics by introducing new potentially hybridizing species or by diminishing barriers to hybridization. This may even affect sympatric species pairs through environmental change, which so far has received little attention. We studied hybridization prevalence and the underlying behavioral mechanisms in two sympatric grasshopper species, a rare specialist (Chorthippus montanus) and a common generalist (Chorthippus parallelus). We conducted a mate choice experiment with constant intraspecific density and varying heterospecific density, i.e. varying relative frequency of both species. RESULTS: Mate choice was frequency-dependent in both species with a higher risk of cross-mating with increasing heterospecific frequency, while conspecific mating increased linearly with increasing conspecific density. This illustrates that reproductive barriers could be altered by environmental change, if the relative frequency of species pairs is affected. Moreover, we performed a microsatellite analysis to detect hybridization in twelve syntopic populations (and four allotopic populations). Hybrids were detected in nearly all syntopic populations with hybridization rates reaching up to 8.9 %. Genetic diversity increased for both species when hybrids were included in the data set, but only in the common species a positive correlation between hybridization rate and genetic diversity was detected. CONCLUSION: Our study illustrates that the relative frequency of the two species strongly determines the effectiveness of reproductive barriers and that even the more choosy species (Ch. montanus) may face a higher risk of hybridization if population size decreases and its relative frequency becomes low compared to its sister species. The asymmetric mate preferences of both species may lead to quasi-unidirectional gene flow caused by unidirectional backcrossing. This might explain why genetic diversity increased only in the common species, but not in the rare one. Altogether, the hybridization rate was much higher than expected for a widely sympatric species pair.


Asunto(s)
Saltamontes/clasificación , Saltamontes/genética , Simpatría , Animales , Ecosistema , Femenino , Flujo Génico , Variación Genética , Hibridación Genética , Masculino , Preferencia en el Apareamiento Animal , Reproducción
18.
Ecol Lett ; 18(6): 581-92, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25865805

RESUMEN

Understanding varying levels of biodiversity within cities is pivotal to protect it in the face of global urbanisation. In the early stages of urban ecology studies on intra-urban biodiversity focused on the urban-rural gradient, representing a broad generalisation of features of the urban landscape. Increasingly, studies classify the urban landscape in more detail, quantifying separately the effects of individual urban features on biodiversity levels. However, while separate factors influencing biodiversity variation among cities worldwide have recently been analysed, a global analysis on the factors influencing biodiversity levels within cities is still lacking. We here present the first meta-analysis on intra-urban biodiversity variation across a large variety of taxonomic groups of 75 cities worldwide. Our results show that patch area and corridors have the strongest positive effects on biodiversity, complemented by vegetation structure. Local, biotic and management habitat variables were significantly more important than landscape, abiotic or design variables. Large sites greater than 50 ha are necessary to prevent a rapid loss of area-sensitive species. This indicates that, despite positive impacts of biodiversity-friendly management, increasing the area of habitat patches and creating a network of corridors is the most important strategy to maintain high levels of urban biodiversity.


Asunto(s)
Biodiversidad , Ciudades , Conservación de los Recursos Naturales , Ecosistema , Ecología/métodos , Urbanización
19.
Ecol Lett ; 18(12): 1366-75, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26468006

RESUMEN

Hybridisation is increasingly recognised as an important cause of diversification and adaptation. Here, we show how divergence in male secondary sexual characters between two lineages of the common wall lizard (Podarcis muralis) gives rise to strong asymmetries in male competitive ability and mating success, resulting in asymmetric hybridisation upon secondary contact. Combined with no negative effects of hybridisation on survival or reproductive characters in F1-hybrids, these results suggest that introgression should be asymmetric, resulting in the displacement of sexual characters of the sub-dominant lineage. This prediction was confirmed in two types of secondary contact, across a natural contact zone and in two introduced populations. Our study illustrates how divergence in sexually selected traits via male competition can determine the direction and extent of introgression, contributing to geographic patterns of genetic and phenotypic diversity.


Asunto(s)
Hibridación Genética , Lagartos/genética , Preferencia en el Apareamiento Animal , Animales , Conducta Competitiva , Femenino , Francia , Alemania , Italia , Masculino , Selección Genética
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA