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Transformations in Latin American Judaism

Se trata de un breve artículo que da cuenta de las transformaciones acontecidas en el judaísmo latinoamericano desde finales del siglo XX, señalando, de un lado, los procesos de revitalización de las corrientes ortodoxas, y del otro, la fluidización de las fronteras del campo que habilita formas de circulación y reapropiación de referencias simbólicas en el proceso de construcción individual de la identidad.Fil: Setton, Eli Damian. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Centro de Estudios e Investigaciones Laborales; Argentin

Natural selection. III. Selection versus transmission and the levels of selection

George Williams defined an evolutionary unit as hereditary information for which the selection bias between competing units dominates the informational decay caused by imperfect transmission. In this article, I extend Williams' approach to show that the ratio of selection bias to transmission bias provides a unifying framework for diverse biological problems. Specific examples include Haldane and Lande's mutation-selection balance, Eigen's error threshold and quasispecies, Van Valen's clade selection, Price's multilevel formulation of group selection, Szathmary and Demeter's evolutionary origin of primitive cells, Levin and Bull's short-sighted evolution of HIV virulence, Frank's timescale analysis of microbial metabolism, and Maynard Smith and Szathmary's major transitions in evolution. The insights from these diverse applications lead to a deeper understanding of kin selection, group selection, multilevel evolutionary analysis, and the philosophical problems of evolutionary units and individuality

Selection-mutation balance models with epistatic selection

We present an application of birth-and-death processes on configuration spaces to a generalized mutation4 selection balance model. The model describes the aging of population as a process of accumulation of mu5 tations in a genotype. A rigorous treatment demands that mutations correspond to points in abstract spaces. 6 Our model describes an infinite-population, infinite-sites model in continuum. The dynamical equation which 7 describes the system, is of Kimura-Maruyama type. The problem can be posed in terms of evolution of states 8 (differential equation) or, equivalently, represented in terms of Feynman-Kac formula. The questions of interest 9 are the existence of a solution, its asymptotic behavior, and properties of the limiting state. In the non-epistatic 10 case the problem was posed and solved in [Steinsaltz D., Evans S.N., Wachter K.W., Adv. Appl. Math., 2005, 11 35(1)]. In our model we consider a topological space X as the space of positions of mutations and the influence of epistatic potential

Semiflow selection and Markov selection theorems

The deterministic analog of the Markov property of a time-homogeneous Markov process is the semigroup property of solutions of an autonomous differential equation. The semigroup property arises naturally when the solutions of a differential equation are unique, and leads to a semiflow. We prove an abstract result on measurable selection of a semiflow for the situations without uniqueness. We outline applications to ODEs, PDEs, differential inclusions, etc. Our proof of the semiflow selection theorem is motivated by N. V. Krylov's Markov selection theorem. To accentuate this connection, we include a new version of the Markov selection theorem related to more recent papers of Flandoli & Romito and Goldys et al.Comment: In this revised version we have added a new abstract result in Sec. 2. It is used to correct the Navier-Stokes example in application

Habitat selection

Habitat selection is the behavioural process determining the distribution of individuals among habitats varying in quality, thus affecting individual fitness and population growth. Models of population dynamics often assume that individuals have perfect knowledge about habitat qualities and settle accordingly in the best habitats available. Many studies of dispersal have focused on the movements of individuals away from a site, but knowledge on settlement decisions is still scarce. I investigated settlement and departure decisions in a long-distant migrant, the northern wheatear (Oenanthe oenanthe), breeding in a heterogeneous agricultural landscape. First, I investigated the settlement of wheatears choosing a new territory at the time of territory establishment in spring. I show that territory selection is non-ideal as wheatears did not prefer territories with characteristics most closely predicting individual fitness. Second, I studied the territory selection of experienced breeders which may use many potential cues as they have been breeding in the same area before. The results show that information gathering of experienced breeders is constrained, and that they cannot always settle at a preferred site probably because of the earlier establishment by other individuals. Third, I show that such a priority constraint in territory site selection may be a proximate cause for female-biased dispersal in wheatears and possibly in many other bird species. Fourth, as a first step to link habitat selection behaviour and population dynamics, I investigated habitat-specific population growth. Overall, I show that constraints acting on individual habitat selection result in a greater proportion of individuals breeding in poorer habitats than would be expected from ideal selection, which has consequences for population persistence

Darwinian Adverse Selection

We develop a model to study the role of rationality in economics and biology. The model's agents differ continuously in their ability to make rational choices. The agents' objective is to ensure their individual survival over time or, equivalently, to maximize profits. In equilibrium, however, rational agents who maximize their objective survival probability are, individually and collectively, eliminated by the forces of competition. Instead of rationality, there emerges a unique distribution of irrational players who are individually not fit for the struggle of survival. The selection of irrational players over rational ones relies on the fact that all rational players coordinate on the same optimal action, which leaves them collectively undiversified and thus vulnerable to aggregate risks.Comment: Maximization, Rationality, Economics, Biology, Group Selectio

Postcopulatory sexual selection

The female reproductive tract is where competition between the sperm of different males takes place, aided and abetted by the female herself. Intense postcopulatory sexual selection fosters inter-sexual conflict and drives rapid evolutionary change to generate a startling diversity of morphological, behavioural and physiological adaptations. We identify three main issues that should be resolved to advance our understanding of postcopulatory sexual selection. We need to determine the genetic basis of different male fertility traits and female traits that mediate sperm selection; identify the genes or genomic regions that control these traits; and establish the coevolutionary trajectory of sexes