Search results for "evolution"
showing 10 items of 11096 documents
Revision of Recent and fossil Mixtacandona Klie 1938 (Ostracoda, Candonidae) from Italy, with description of a new species
2017
Although studies on ostracods dwelling in inland subterranean habitats of Italy have increased in the last decades, highlighting a considerable taxonomic diversity, available information is still far from sufficient to understand phylogenetic and biogeographic relationships. Mixtacandona Klie 1938 is one of the most common and diverse genera of ostracods in subterranean waters. Of the 20 living recognized species in the genus, all stygobiontic and restricted to the Palearctic Region, four are known for the Italian peninsula and Sardinia, one of which exclusively as fossil. Several other Recent and fossil taxa attributable to Mixtacandona, but identified at supraspecific level, have been rep…
Energy and speleogenesis: Key determinants of terrestrial species richness in caves
2017
Abstract The aim of this study was to unravel the relative role played by speleogenesis (i.e., the process in which a cave is formed), landscape‐scale variables, and geophysical factors in the determination of species richness in caves. Biological inventories from 21 caves located in the southeastern Iberian Peninsula along with partial least square (PLS) regression analysis were used to assess the relative importance of the different explanatory variables. The caves were grouped according to the similarity in their species composition; the effect that spatial distance could have on similarity was also studied using correlation between matrices. The energy and speleogenesis of caves account…
The role of maternal effects in host-parasite interactions: examination of the development of the immune defense in a colonial seabird, the black-leg…
2004
One of the main aims of evolutionary biology is to understand the mechanisms responsible for the phenotypic variation on which natural selection can act. Maternal effects occur when a mother's phenotype or her environment influence her offspring's phenotype. Despite the importance of such effects for the ecology of host-parasite interactions, their role has been relatively neglected to date. In this thesis, we examined how mothers influence the immune defense of their young in an environment that varies in space and time. This work has primarily focused on a colonial seabird, the black-legged kittiwake (Rissa tridactyla). Using this model, we have first shown that specific maternal antibodi…
Focusing on Ciona intestinalis (Tunicata) innate immune system. Evolutionary implications
2009
Phylogenetic analyses based on molecular data provide compelling evidence that ascidians are of critical importance for studying chordate immune system evolution. The Ciona intestinalis draft genome sequence allows searches for phylogenetic relationships, gene cloning and expression of immunorelevant molecules. Acidians lack of the pivotal components of the vertebrate recombinatory adaptive immunity, i.e., MHC, TCRs and dimeric immunoglobulins. However, bioinformatic sequence analyses recognized genic elements indicating the essential features of the Ig superfamily and ancestor proto-MHC genes, suggesting a primitive pre-duplication and pre-recombination status. C. intestinalis genes for in…
“The Best Laid Plans” : Do Individual Differences in Planfulness Moderate Effects of Implementation Intention Interventions?
2022
While there is good evidence supporting the positive effect of planning strategies like implementation intentions on the relationship between intention and behavior, there is less evidence on the moderating role of individual differences in planning capacity on this effect. This study aimed to examine the role of individual differences in planfulness on the effect of planning strategies on the intention–behavior gap. Specifically, this study investigated the influence of planfulness on the effectiveness of implementation intentions on goal-directed behavior using an experimental design. Undergraduate university students (N = 142) with high and low levels of planfulness based on a priori sco…
Host Developmental Stage Effects on Parasite Resistance and Tolerance.
2022
Hosts can defend themselves against parasites either by preventing or limiting infections (resistance) or by limiting parasite-induced damage (tolerance). However, it remains underexplored how these defense types vary over host development with shifting patterns of resource allocation priorities. Here, we studied the role played by developmental stage in resistance and tolerance in Atlantic salmon (Salmo salar). This anadromous fish has distinct life stages related to living in freshwater and seawater. We experimentally exposed 1-year-old salmon, either at the freshwater stage or at the stage transitioning to the marine phase, to the trematode Diplostomum pseudospathaceum. Using 56 pedigree…
Interstitial Telomeric-like Repeats (ITR) in Seed Plants as Assessed by Molecular Cytogenetic Techniques: A Review.
2021
The discovery of telomeric repeats in interstitial regions of plant chromosomes (ITRs) through molecular cytogenetic techniques was achieved several decades ago. However, the information is scattered and has not been critically evaluated from an evolutionary perspective. Based on the analysis of currently available data, it is shown that ITRs are widespread in major evolutionary lineages sampled. However, their presence has been detected in only 45.6% of the analysed families, 26.7% of the sampled genera, and in 23.8% of the studied species. The number of ITR sites greatly varies among congeneric species and higher taxonomic units, and range from one to 72 signals. ITR signals mostly occurs…
Trade And Environment: A Historical Perspective
2015
Abstract The relation between international trade and environmental and social issues has deep historical roots, having been manifest ever since the first industrial revolution. Ironically, the expansion of industrial activities marked, besides the exit from economic backwardness, the commencement of an inexorable war of men against nature. Concomitantly industrialization laid the groundwork for an explosive increase in international trade, which made the latter responsible for increasing environment degradation and social rights infringement. The removal of trade barriers in the first decades after the Second World War as well as the subsequent regulation induced by globalization rendered …
The Nanoeconomics of Firm‐Level Decision‐Making and Industry Evolution : Evidence from 200 Years of Paper and Pulp Making
2020
Research summary We explore the qualitative differences in entries and exits over time. Using qualitative and quantitative data on 96 firms over 200 years, we study industry evolution from the perspective of individual decision‐making situations. Our historical and statistical analyses reveal the vital role of technology investments in determining firm outcomes, and the technological, institutional and governance dynamics that lead firms to invest or to abstain. Our main theoretical and methodological contribution concerns the importance of the multiplicity of firm‐level rationalities and decisions as fundamentals in theorizing on industry evolution. Managerial summary What determines firm …
Droplet digital PCR as a tool for investigating dynamics of cryptic symbionts
2021
Abstract Interactions among symbiotic organisms and their hosts are major drivers of ecological and evolutionary processes. Monitoring the infection patterns among natural populations and identifying factors affecting these interactions are critical for understanding symbiont–host relationships. However, many of these interactions remain understudied since the knowledge about the symbiont species is lacking, which hinders the development of appropriate tools. In this study, we developed a digital droplet PCR (ddPCR) assay based on apicomplexan COX1 gene to detect an undescribed agamococcidian symbiont. We show that the method gives precise and reproducible results and enables detecting cryp…