DOMINANCE IN MULTI-POPULATION CULTURAL ALGORITHMS

We propose a new approach that can be used for solving the knowledge migration issue in multi-population cultural algorithms (MPCA). In this study we introduce a new method to enable the migration of individuals from one population to another using the concept of complete dominance applied to MPCA. The MPCA’s artificial population comprises of agents that belong to a certain sub-population. In this work we create a dominance multi population cultural algorithm (D-MPCA) with a network of populations that implements a dominance strategy. We hypothesize that the evolutionary advantage of dominance can help improve the performance of MPCA in general optimization problems. Three benchmark optimization functions are used to calculate the fitness value of the individuals. The proposed D-MPCA showed improved performance over the traditional MPCA. We conclude that dominance helps in improving the efficiency of knowledge migration in MPCA

Cooperation in self-organized heterogeneous swarms

Cooperation in self-organized heterogeneous swarms is a phenomenon from nature with many applications in autonomous robots. I specifically analyzed the problem of auto-regulated team formation in multi-agent systems and several strategies to learn socially how to make multi-objective decisions. To this end I proposed new multi-objective ranking relations and analyzed their properties theoretically and within multi-objective metaheuristics. The results showed that simple decision mechanism suffice to build effective teams of heterogeneous agents and that diversity in groups is not a problem but can increase the efficiency of multi-agent systems

The role of visual adaptation in cichlid fish speciation

D. Shane Wright (1) , Ole Seehausen (2), Ton G.G. Groothuis (1), Martine E. Maan (1) (1) University of Groningen; GELIFES; EGDB(2) Department of Fish Ecology & Evolution, EAWAG Centre for Ecology, Evolution and Biogeochemistry, Kastanienbaum AND Institute of Ecology and Evolution, Aquatic Ecology, University of Bern.In less than 15,000 years, Lake Victoria cichlid fishes have radiated into as many as 500 different species. Ecological and sexual sel ection are thought to contribute to this ongoing speciation process, but genetic differentiation remains low. However, recent work in visual pigment genes, opsins, has shown more diversity. Unlike neighboring Lakes Malawi and Tanganyika, Lake Victoria is highly turbid, resulting in a long wavelength shift in the light spectrum with increasing depth, providing an environmental gradient for exploring divergent coevolution in sensory systems and colour signals via sensory drive. Pundamilia pundamila and Pundamilia nyererei are two sympatric species found at rocky islands across southern portions of Lake Victoria, differing in male colouration and the depth they reside. Previous work has shown species differentiation in colour discrimination, corresponding to divergent female preferences for conspecific male colouration. A mechanistic link between colour vision and preference would provide a rapid route to reproductive isolation between divergently adapting populations. This link is tested by experimental manip ulation of colour vision - raising both species and their hybrids under light conditions mimicking shallow and deep habitats. We quantify the expression of retinal opsins and test behaviours important for speciation: mate choice, habitat preference, and fo raging performance

Advances in Evolutionary Algorithms

With the recent trends towards massive data sets and significant computational power, combined with evolutionary algorithmic advances evolutionary computation is becoming much more relevant to practice. Aim of the book is to present recent improvements, innovative ideas and concepts in a part of a huge EA field

An agent-based computational model of the evolution of reproductive isolation in populations of digital plants

The process of speciation is a fascinating area of research in the biological sciences. Development of mathematical and computational models are an important part of developing speciation theory. The Pseudophyte Evolutionary Algorithm PEA is a individual-based population model developed to test hypotheses concerning process of speciation. The individuals pseudophytes are digital plants. Biologically, they are haploid annuals, each producing pollen and ovules. Pseudophytes are implemented as binary strings representing loci which encoded six traits. Loci were divided into two chromosomes each with three traits. The loci are mapped to a phenotype which determines the behavior of the pseudophyte. The PEA examines the evolution of pre-mating (accepting or rejecting pollen) and postzygotic (offspring inviability) reproductive isolation. Experiments were performed to study the effect of habitat fragmentation, number of loci, method of computing the energy need of a pseudophytes, ovule production, and linkage on the rate at which reproductive isolation evolves. Speciation occurred under low levels of habitat fragmentation, but not high. The effect of moderate habitat fragmentation resulted in faster and more complete reproductive isolation when simulations began with specialist, but speciation did not occur when the initial populations consisted of generalists. Increasing the number of loci tended to delay speciation and result in less between and more within habitat postzygotic isolation. Energy need computation that imposed greater requirements resulted in fewer instances of speciation and less reproductive isolation when it did occur. Linkage experiments revealed complex interaction between the traits.*;*This dissertation is a compound document (contains both a paper copy and a CD as part of the dissertation). The CD requires the following system requirements: Adobe Acrobat; WinZip

ECOLOGICAL PERSPECTIVES ON HOST-PARASITE COEVOLUTION

It is a truth universally acknowledged that polymorphism at host immunity loci and corresponding parasite antigenicity loci, maintained by coevolution in pathosystems, is common and can persist for millions of years. Such polymorphisms and how they persist or break down are both fundamentally interesting and important for human health and agriculture. Examples include the major histocompatibility complex in vertebrates and the gene-for-gene (GFG) relationships in plants and their parasites. GFG systems are well-understood genetically and an important source of disease resistance for plant breeders. Therefore considerable effort has gone into studying their evolutionary dynamics in natural pathosystems and modelling the conditions under which long-term polymorphism persists or breaks down. Polymorphism in GFG systems is common and in many cases ancient in wild pathosystems. Conversely, in agriculture the introduction of a resistance gene normally results in the matching parasite avirulence gene rapidly becoming locally extinct. Simple genetic models of GFG coevolution do not produce stable polymorphism. Various more complex models do but are difficult to analyse. Recent work has shown a factor common to stable models is negative direct frequency-dependent selection, so at least one genotype becomes less fit as it grows more common regardless of genotype frequencies in the other species. This selection is not present in simplified models, but is generated in real pathosystems by various ecological and epidemiological factors. Here I expand on previous work by demonstrating that realistic demography, specifically density-dependent regulation of parasite incidence, can generate negatively self-regulating stabilising pressure. This is loosely analogous to negative frequency-dependent selection and, similarly, can stabilise polymorphism in GFG pathosystems. I show this density-dependent regulation can stabilise both non-spatial deterministic and spatial stochastic systems. I also study how this stabilising factor interacts with the complicating biological factors of limited dispersal and resultant spatial structure in populations, variable host density and the presence of a second parasite

Aneuploidy in Health and Disease

Aneuploidy means any karyotype that is not euploid, anything that stands outside the norm. Two particular characteristics make the research of aneuploidy challenging. First, it is often hard to distinguish what is a cause and what is a consequence. Secondly, aneuploidy is often associated with a persistent defect in maintenance of genome stability. Thus, working with aneuploid, unstable cells means analyzing an ever changing creature and capturing the features that persist. In the book Aneuploidy in Health and Disease we summarize the recent advances in understanding the causes and consequences of aneuploidy and its link to human pathologies

An overview of the genetics and genomics of the Urochloa Species Most Commonly used in pastures.

Pastures based on perennial monocotyledonous plants are the principal source of nutrition for ruminant livestock in tropical and subtropical areas across the globe. The Urochloa genus comprises important species used in pastures, and these mainly include Urochloa brizantha, Urochloa decumbens, Urochloa humidicola, and Urochloa ruziziensis. Despite their economic relevance, there is an absence of genomic-level information for these species, and this lack is mainly due to genomic complexity, including polyploidy, high heterozygosity, and genomes with a high repeat content, which hinders advances in molecular approaches to genetic improvement. Next-generation sequencing techniques have enabled the recent release of reference genomes, genetic linkage maps, and transcriptome sequences, and this information helps improve our understanding of the genetic architecture and molecular mechanisms involved in relevant traits, such as the apomictic reproductive mode. However, more concerted research efforts are still needed to characterize germplasm resources and identify molecular markers and genes associated with target traits. In addition, the implementation of genomic selection and gene editing is needed to reduce the breeding time and expenditure. In this review, we highlight the importance and characteristics of the four main species of Urochloa used in pastures and discuss the current findings from genetic and genomic studies and research gaps that should be addressed in future research.bitstream/item/229032/1/OverviewGeneticsGenomics.pd