Search results for "evolutionary"
showing 10 items of 4392 documents
Antipredatory function of head shape for vipers and their mimics.
2011
Most research into the adaptive significance of warning signals has focused on the colouration and patterns of prey animals. However, behaviour, odour and body shape can also have signal functions and thereby reduce predators' willingness to attack defended prey. European vipers all have a distinctive triangular head shape; and they are all venomous. Several non-venomous snakes, including the subfamily Natricinae, commonly flatten their heads (also known as head triangulation) when disturbed. The adaptive significance of this potential behavioural mimicry has never been investigated. We experimentally tested if the triangular head shape typical of vipers offers protection against predation.…
The Mediterranean weedy vegetation and its origin
2007
An overview on the origin and evolutionary trends in the Mediterranean weedy vegetation is presented, with reference to the phytosociological units to which they are ascribed: Stellarietea mediae, Papaveretea rhoeadis, Oryzetea sativae. It is postulated that the “Neolithic revolution” was more likely a “Neolithic evolution”, i.e. the result of a process of selection and demographic growth that lasted for at least 10000 yrs, before leading to the domestication of plants and animals. During this very long time, wild crop relatives were simply growing together with the wild weed relatives, in their original milieu. At the beginning of agriculture, fields…
Evolucionismo, integración sociocognitiva y cambio semántico
2014
El cambio es el fenómeno lingüístico por excelencia a la hora de aplicar los modelos teóricos evolucionistas. La perspectiva evolucionista del lenguaje permite analizar el cambio lingüístico como un fenómeno sujeto a los mismos procesos evolutivos que determinan cualquier sistema evolutivo complejo. El objetivo de este estudio es defender una integración más sistemática de los factores sociales y cognitivos del cambio lingüístico, en particular del cambio semántico. Este artículo se centra en un enfoque evolutivo del cambio lingüístico muy influyente, la Teoría de la Selección del Enunciado del cambio lingüístico desarrollada por Croft (2000). El enfoque evolutivo de Croft se inspira en la …
Analogia e omologia: la questione della filogenesi delle emozioni
2013
Aim of this paper is to outline a new evolutionary interpretation of aesthetic emotions, in the light of the most recent developments in Evolutionary Biology, in particular the so-called “Extended Synthesis of Evolution” (Pigliucci-Müller 2010). Focussing on the biological concept of homology, the Author argues that, in order to effectively understand role and evolutionary value of aesthetic emotions, it should be asked not “what aesthetic emotions are for?”, rather “what kind of constraints and homologies influence the specific “shape” of human aesthetic emotions?”. In a few words, we should move from a functionalist approach to human aesthetic emotions towards a morphological one.
Bacterial and phytoplankton responses to nutrient amendments in a boreal lake differ according to season and to taxonomic resolution
2011
Nutrient limitation and resource competition in bacterial and phytoplankton communities may appear different when considering different levels of taxonomic resolution. Nutrient amendment experiments conducted in a boreal lake on three occasions during one open water season revealed complex responses in overall bacterioplankton and phytoplankton abundance and biovolume. In general, bacteria were dominant in spring, while phytoplankton was clearly the predominant group in autumn. Seasonal differences in the community composition of bacteria and phytoplankton were mainly related to changes in observed taxa, while the differences across nutrient treatments within an experiment were due to chang…
Phenotypic Buffering in a Monogenean: Canalization and Developmental Stability in Shape and Size of the Haptoral Anchors of Ligophorus cephali (Monog…
2015
Phenotypic variation results from the balance between sources of variation and counteracting regulatory mechanisms. Canalization and developmental stability are two such mechanisms, acting at two different levels of regulation. The issue of whether or not they act concurrently as a common developmental buffering capacity has been subject to debate. We used geometric morphometrics to quantify the mechanisms that guarantee phenotypic constancy in the haptoral anchors of Ligophorus cephali. Canalization and developmental stability were appraised by estimating inter- and intra-individual variation, respectively, in size and shape of dorsal and ventral anchors. The latter variation was estimated…
A Combined Multi-Cohort Approach Reveals Novel and Known Genome-Wide Selection Signatures for Wool Traits in Merino and Merino-Derived Sheep Breeds.
2019
Merino sheep represents a valuable genetic resource worldwide. In this study, we investigated selection signatures in Merino (and Merino-derived) sheep breeds using genome-wide SNP data and two different approaches: a classical F-ST-outlier method and an approach based on the analysis of local ancestry in admixed populations. In order to capture the most reliable signals, we adopted a combined, multi-cohort approach. In particular, scenarios involving four Merino breeds (Spanish Merino, Australian Merino, Chinese Merino, and Sopravissana) were tested via the local ancestry approach, while nine pair-wise breed comparisons contrasting the above breeds, as well as the Gentile di Puglia breed, …
Erratum for Piwosz et al., "Light and Primary Production Shape Bacterial Activity and Community Composition of Aerobic Anoxygenic Phototrophic Bacter…
2020
Metabolic coupling between phytoplankton and bacteria determines the fate of dissolved organic carbon in aquatic environments, and yet how changes in the rate of primary production affect the bacterial activity and community composition remains understudied. Here, we experimentally limited the rate of primary production either by lowering light intensity or by adding a photosynthesis inhibitor. The induced decrease had a greater influence on bacterial respiration than on bacterial production and growth rate, especially at an optimal light intensity. This suggests that changes in primary production drive bacterial activity, but the effect on carbon flow may be mitigated by increased bacteria…
Empirical links between natural mortality and recovery in marine fishes
2017
Probability of species recovery is thought to be correlated with specific aspects of organismal life history, such as age at maturity and longevity, and how these affect rates of natural mortality ( M ) and maximum per capita population growth ( r max ). Despite strong theoretical underpinnings, these correlates have been based on predicted rather than realized population trajectories following threat mitigation. Here, we examine the level of empirical support for postulated links between a suite of life-history traits (related to maturity, age, size and growth) and recovery in marine fishes. Following threat mitigation (medium time since cessation of overfishing = 20 years), 71% of 55 tem…
Increasing temperature and productivity change biomass, trophic pyramids and community‐level omega‐3 fatty acid content in subarctic lake food webs
2021
Climate change in the Arctic is outpacing the global average and land-use is intensifying due to exploitation of previously inaccessible or unprofitable natural resources. A comprehensive understanding of how the joint effects of changing climate and productivity modify lake food web structure, biomass, trophic pyramid shape and abundance of physiologically essential biomolecules (omega-3 fatty acids) in the biotic community is lacking. We conducted a space-for-time study in 20 subarctic lakes spanning a climatic (+3.2 degrees C and precipitation: +30%) and chemical (dissolved organic carbon: +10 mg/L, total phosphorus: +45 mu g/L and total nitrogen: +1,000 mu g/L) gradient to test how temp…