Search results for " evolution."
showing 10 items of 9653 documents
Sisubiotus hakaiensis sp. nov. (Tardigrada, Macrobiotidae), a new tardigrade species from Calvert Island (British Columbia, Canada)
2022
Tardigrades reports from British Columbia (Canada) trace back to 1908 and numerous species have been recorded from this region, despite the relatively few published sampling studies. We describe by integrative taxonomy (light microscopy morphology, morphometrics, and DNA sequencing) a new tardigrade species, Sisubiotus hakaiensis sp. nov. from the British Columbia central coast. The new species has been found in moss collected from a vertical rock outcrop near the Hakai Institute Calvert Island Field Station. Sisubiotus hakaiensis sp. nov. differs from all the other known species in the genus by the presence of a labyrinthine layer inside the egg process walls, whereas no consistent differe…
Chemicals and chemoreceptors: ecologically relevant signals driving behavior in Drosophila
2015
Insects encounter a vast repertoire of chemicals in their natural environment, which can signal positive stimuli like the presence of a food source, a potential mate, or a suitable oviposition site as well as negative stimuli such as competitors, predators, or toxic substances reflecting danger. The presence of specialized chemoreceptors like taste and olfactory receptors allows animals to detect chemicals at short and long distances and accordingly, trigger proper behaviors toward these stimuli. Since the first description of olfactory and taste receptors in Drosophila melanogaster 15 years ago, our knowledge on the identity, properties, and function of specific chemoreceptors has increase…
Sensitivity of bipartite network analyses to incomplete sampling and taxonomic uncertainty
2023
Bipartite network analysis is a powerful tool to study the processes structuring interactions in ecological communities. In applying the method, it is assumed that the sampled interactions provide an accurate representation of the actual community. However, acquiring a representative sample may be difficult as not all species are equally abundant or easily identifiable. Two potential sampling issues can compromise the conclusions of bipartite network analyses: failure to capture the full range of interactions (sampling completeness) and use of a taxonomic level higher than species to evaluate the network (taxonomic resolution). We asked how commonly used descriptors of bipartite antagonisti…
Additions to terrestrial flora of Tunisia: occurrence and taxonomic notes
2020
We document new records of 11 vascular taxa. Some were found in the wild for the first time and, therefore, are new reports to terrestrial flora of Tunisia. One species, Ranunculus acris L., is reported for the first time for North Africa. Parietaria cretica L. is confirmed for North Africa. Details about the distribution and habitats of the 11 species are provided, and comments on their status and taxonomy are included.
El lenguaje de las tecnologías en la formación de maestros
2020
Este artículo se encuentra disponible a texto completo en la siguiente URL: https://revistas.uam.es/tendenciaspedagogicas/article/view/tp2020_36_09 Este número monográfico de la revista Tendencias Pedagógicas lleva por título "La alfabetización académica". Este trabajo pretende reflexionar sobre las implicaciones educativas que hoy día tiene la competencia mediática en los procesos de enseñanza-aprendizaje. La evolución de las TIC y, sobre todo, de la tecnología móvil, ha provocado una revolución comunicativa educativa y social que afecta al mundo educativo; los contextos edu-cativos son cambiantes y evolucionan rápido, teniendo que adaptarse a los cambios socioculturales, tecnológi-cos, et…
Tectono-sedimentary evolution of wedge-top basins in the north-western Sicilian Maghrebides (Italy)
2012
Gill area explains deviations from body size–metabolic rate relationship in teleost fishes
2022
Whether gill area constrains fish metabolism through oxygen limitation is a debated topic. Here, the authors provide insights into this question by analysing mass-specific metabolic rates across 44 teleost fishes extracted from FishBase. They explore whether species deviations from metabolic rates predicted by body mass can be explained by species gill area. They show that the gill area explains c. 26%–28% of species-level deviations from mass-specific metabolic rates. Their findings suggest that gill area might indeed be one of the factors limiting metabolic rate in fishes.
Prenatal thyroid hormones accelerate postnatal growth and telomere shortening in wild great tits
2021
AbstractEarly-life environment is known to affect later-life health and disease, which could be mediated by the early-life programming of telomere length, a key hallmark of ageing. According to thefetal programming of telomere biology hypothesis, variation in prenatal exposure to hormones is likely to influence telomere length. Yet the contribution of key metabolic hormones,i.e. thyroid hormones (THs), has been largely ignored. We recently showed that in contrast to predictions, exposure to elevated prenatal THs increased postnatal telomere length in wild collared flycatchers, but the generality of such effect, its underlying proximate mechanisms and consequences on survival have not been i…
Atmospheric brightening counteracts warming‐induced delays in autumn phenology of temperate trees in Europe
2021
Aim: Ongoing climate warming has been widely reported to delay autumn phenology, which in turn impacts carbon, water, energy and nutrient balances at regional and global scales. However, the underlying mechanisms of autumn phenology responses to climate change have not been fully elucidated. The aims of this study were to determine whether brightening that was defined as the increase of surface solar radiation and warming during recent decades affect autumn phenology in opposite directions and explore the underlying mechanisms. Location: Central Europe. Time period: 1950–2016. Major taxa studied: Four dominant European tree species in central Europe: Aesculus hippocastanum, Betula pendula, …
Filipinas en el marco del imperio español en el siglo XIX
2019
[EN] En este artículo se analiza la evolución de Filipinas en las últimas décadas del siglo XVIII y en el transcurso del siglo XIX a través de diferentes epígrafes: la obligada transformación del secular modelo colonial volcado hacia el tráfico del Galeón y las relaciones transpacíficas; la renovada inclinación hacia Asia, el océano Índico y el mar de China; el desarrollo de un sistema económico basado en la exportación de productos filipinos y en la apertura de las islas al exterior; la evolución de la vida política; el camino hacia la modernización; el peso de las órdenes religiosas, la importancia de la población china y la colaboración con élites indígenas como rasgos singulares de Fili…