Search results for "adaptation"
showing 10 items of 1775 documents
Within-host evolution decreases virulence in an opportunistic bacterial pathogen
2015
Abstract Background Pathogens evolve in a close antagonistic relationship with their hosts. The conventional theory proposes that evolution of virulence is highly dependent on the efficiency of direct host-to-host transmission. Many opportunistic pathogens, however, are not strictly dependent on the hosts due to their ability to reproduce in the free-living environment. Therefore it is likely that conflicting selection pressures for growth and survival outside versus within the host, rather than transmission potential, shape the evolution of virulence in opportunists. We tested the role of within-host selection in evolution of virulence by letting a pathogen Serratia marcescens db11 sequent…
Adaptation and implementation of the German social-emotional learning programme Papilio in Finland : A pilot study
2019
This study investigated the cross‐national adaptation and implementation of Papilio, a German social–emotional learning programme, in Finnish early childhood education and care (ECEC) centres. Papilio is a developmentally focused, scientifically based intervention programme focused on preventing behavioural problems and fostering social–emotional competence in children aged 3–7. The aim of this study was to investigate and evaluate the cross‐national adaptation and cross‐cultural adaptation and implementation of Papilio in the Finnish ECEC context. Results from qualitative interviews with one Finnish Papilio trainer, 11 early childhood education (ECE) teachers, two ECE special education tea…
Life-history variation, environmental fluctuations and competition in ecologically similar species: modeling the case of rotifers
2015
Competition for resources can lead to species exclusion. However, this exclusion may be avoided if species show differential adaptation to physical environment. Empirical studies on competition are difficult when species are phylogenetically close and have complex life cycles. This is the case of B. plicatilis and B. manjavacas, two cryptic rotifer species differing in their salinity niches and in life-history traits related to sex and diapause. These differences have been suggested to promote the stable co-occurrence observed in natural populations of these species. However, in a previous empirical study, the outcome of competition between both species was always exclusion. Here, we theore…
Climb Every Mountain?
2003
2 pages, 1 figure.-- PMID: 14684807 [PubMed].
'Niche Selection' and the evolution of a complex behavior in a changing environment--a simulation.
2000
One of the key problems in theoretical biology is the identification of the mechanisms underlying the evolution of complexity. This paper suggests that some difficulties in current models could be avoided by taking account of “niche selection” as proposed by Waddington [21] and subsequent authors [2]. Computer simulations, in which an evolving population of artificial organisms “selects” the niche(s) that maximize their fitness, are compared with a Control Model in which “Niche Selection” is absent. In the simulations the Niche Selection Model consistently produced a greater number of “fit” organisms than the Control Model; although the Niche Selection Model tended, in general, to produce o…
Genomic signatures of recent adaptation in a wild bumblebee
2021
AbstractBehavioral experiments and analyses of observation records have shown that environmental changes threaten insect pollinators, creating risks for agriculture and ecosystem stability. Despite their importance, we know little about how wild insects or other animals can adapt in response to environmental pressures. To understand the genomic bases of adaptation in an ecologically important pollinator, we analyzed genomes ofBombus terrestrisbumblebees collected across Great Britain. We reveal extensive genetic diversity within this population, and strong signatures of recent adaptation throughout the genome. More specifically, we find that selection recently affected key processes underpi…
Conditions for the spread of conspicuous warning signals: A numerical model with novel insights
2007
The initial evolution of conspicuous warning signals presents an evolutionary problem because selection against rare conspicuous signals is presumed to be strong, and new signals are rare when they first arise. Several possible solutions have been offered to solve this apparent evolutionary paradox, but disagreement persists over the plausibility of some of the proposed mechanisms. In this paper, we construct a deterministic numerical simulation model that allows us to derive the strength of selection on novel warning signals in a wide range of biologically relevant situations. We study the effects of predator psychology (learning, rate of mistaken attacks, and neophobia) on selection. We a…
The curvilinear effect of manufacturing outsourcing and captive-offshoring on firms' innovation: The role of temporal endurance
2019
Abstract This paper aims to contribute to the open debate in the literature on the effect of global sourcing strategies on firm performance by studying the consequences of manufacturing outsourcing and captive-offshoring for the innovation capability of the firm. We grounded our hypotheses based on the outsourcing and offshoring literature and by narrowing our focus to the effects of persisting in their adoption over time. We tested our hypotheses using data from a sample of 368 manufacturing companies listed on NASDAQ stock market. The paper provides theoretical explanations and empirical findings for the inverted U-shaped influence of keeping doing captive-offshoring on new product develo…
Adapting to High Temperatures: Effect of Farm Practices and Their Adoption Duration on Total Value of Crop Production in Uganda
2021
In this article, we use spatially granular climate data merged with four waves of household survey data in Uganda to examine empirically the relationships among high temperatures, total value of crop production, and the adoption and adoption duration of two sustainable agricultural practices (organic fertilizer adoption and maize–legume intercropping). We do this using a fixed-effect model with instrumental variables to address potential endogeneity issues. Our findings indicate that the adoption of these practices has a positive effect on the total value of crop production, and such effect increases monotonically as temperatures increase from long-term averages. Moreover, the number of yea…
Knowing is half the battle: Seasonal forecasts, adaptive cropping systems, and the mediating role of private markets in Zambia
2019
Abstract This paper examines how smallholders living in regions where a drought is forecasted adapt their farm practices in response to receiving seasonal forecast information. The article draws on a unique longitudinal dataset in Zambia, which collected information from farm households before and after a significant drought caused by the 2015/2016 El-Nino Southern Oscillation. It finds that farmers residing in areas forecasted to be drought-affected and receiving seasonal forecast information are significantly more likely to integrate drought tolerant crops into their cropping systems compared to similar households not receiving this information. Moreover, the probability that a farmer imp…