Search results for "luu"
showing 10 items of 614 documents
Marine food web perspective to fisheries-induced evolution
2021
Fisheries exploitation can cause genetic changes in heritable traits of targeted stocks. The direction of selective pressure forced by harvest acts typically in reverse to natural selection and selects for explicit life-histories, usually for younger and smaller spawners with deprived spawning potential. While the consequences that such selection might have on the populational dynamics of a single species are well emphasised, we are just beginning to perceive the variety and severity of its propagating effects within the entire marine food webs and ecosystems. Here, we highlight the potential pathways in which fishing-induced evolution, driven by size-selective fishing, might resonate throu…
Building on 150 Years of Knowledge : The Freshwater Isopod Asellus aquaticus as an Integrative Eco-Evolutionary Model System
2021
Interactions between organisms and their environments are central to how biological diversity arises and how natural populations and ecosystems respond to environmental change. These interactions involve processes by which phenotypes are affected by or respond to external conditions (e.g., via phenotypic plasticity or natural selection) as well as processes by which organisms reciprocally interact with the environment (e.g., via eco-evolutionary feedbacks). Organism-environment interactions can be highly dynamic and operate on different hierarchical levels, from genes and phenotypes to populations, communities, and ecosystems. Therefore, the study of organism-environment interactions requir…
Extending the hosts of Tectiviridae into four additional genera of Gram-positive bacteria and more diverse Bacillus species
2018
Tectiviridae are composed of tailless bacteriophages with an icosahedral capsid and an inner membrane enclosing a double-stranded 15 kb linear DNA genome. Five of the seven previously studied Tectivirus isolates infect bacteria from Bacillus cereus sensu lato group (Betatectivirus), one distantly related member (PRD1) infect Enterobactericeae (Alpatectivirus) and one recently discovered virus infect Gluconobacter cerinus (Gammatectivirus). Here we expand the host spectrum of Betatectivirus elements to four additional genera (Streptococcus, Exiguobacterium, Clostridium and Brevibacillus) and to more distantly related Bacillus species (B. pumilus and B. flexus) by studying the genomes of four…
Evolutionary game theory of continuous traits from a causal perspective
2023
Modern evolutionary game theory typically deals with the evolution of continuous, quantitative traits under weak selection, allowing the incorporation of rich biological detail and complicated nonlinear interactions. While these models are commonly used to find candidates for evolutionary endpoints and to approximate evolutionary trajectories, a less appreciated property is their potential to expose and clarify the causal structure of evolutionary processes. The mathematical step of differentiation breaks a nonlinear model into additive components which are more intuitive to interpret, and when combined with a proper causal hypothesis, partial derivatives in such models have a causal meanin…
New insights on the role of ecology and life-history in social evolution
2017
Biological altruism, defined as a behaviour that benefits others at an apparent cost to the focal individual, is found abundantly across different levels of biological organization. While kin selection has been useful for explaining both cooperation and conflict in specialized cooperative societies, more theoretical work has to be done to develop models for realistic ecological and life-history contexts. This thesis aims to fill this gap by providing several new insights on the role of ecology and life-history in various social systems. Firstly, I propose a model that incorporates realistic ecological mechanisms of population regulation and study how different population regulation mechanisms affe…
Genetic diversity in populations of asexual and sexual bag worm moths (Lepidoptera: Psychidae)
2005
BACKGROUND: Despite the two-fold cost of sex, most of the higher animals reproduce sexually. The advantage of sex has been suggested to be its ability, through recombination, to generate greater genetic diversity than asexuality, thus enhancing adaptation in a changing environment. We studied the genetic diversity and the population structure of three closely related species of bag worm moths: two strictly sexual (Dahlica charlottae and Siederia rupicolella) and one strictly asexual (D. fennicella). These species compete for the same resources and share the same parasitoids. RESULTS: Allelic richness was comparable between the sexual species but it was higher than in the asexual species. Al…
Assortment, but not knowledge of assortment, affects cooperation and individual success in human groups
2017
The success or failure of human collective action often depends on the cooperation tendencies of individuals in groups, and on the information that individuals have about each other's cooperativeness. However, it is unclear whether these two factors have an interactive effect on cooperation dynamics. Using a decision-making experiment, we confirm that groups comprising individuals with higher cooperation tendencies cooperate at a higher level than groups comprising individuals with low cooperation tendencies. Moreover, assorting individuals with similar cooperation tendency together affected behaviour so that the most cooperative individuals tended to cooperate more and the least cooperativ…
Opettajien kokemuksia CLIL-opetuksen eriyttämisestä : käsityksiä, käytänteitä ja haasteita
2012
Tämä laadullisen tapaustutkimuksen ja määrällisen kyselytutkimuksen yhdistävä kaksivaiheinen tutkimus käsittelee eriyttämistä CLIL-opetuksessa. Tutkimuksen tarkoituksena on selvittää (1) alakoulussa englanninkielistä CLIL-opetusta toteuttavien opettajien käsityksiä eriyttämisestä, (2) heidän CLIL-opetuksessa käyttämiään eriyttämiskeinoja sekä (3) heidän kokemiaan eriyttämisen haasteita. Tutkimuksen ensimmäisen vaiheen tavoitteena on laadullisen tapaustutkimuksen avulla lisätä ymmärrystä ja tietoutta eriyttämisestä ilmiönä inklusiivisessa CLIL-opetuksessa ja tulla tietoiseksi erilaisista käytännön eriyttämiskeinoista, joita opettajat voivat työssään hyödyntää. Tutkimuksen toinen vaihe selvit…
Classroom behavioural climate in inclusive education – a study on secondary students’ perceptions
2021
Previous studies pointed out that dealing with difficult behaviour is perceived by teachers as a major challenge in inclusive settings. However, research on the students' perception of the classroom behavioural climate (CBC) is rare. Therefore, this study aims to examine students’ perceptions of CBC and to identify predictors of CBC as well as associated variables. The sample consists of 650 German students from secondary schools (5th-9th grade) of whom 83 students are diagnosed with special educational needs (SEN). CBC was measured via four subscales (‘students’ possibilities to study and concentrating on teaching’, ‘disruptive behaviour’, ‘physical and psychological safety’ and ‘caring fo…