Selection Of Migrants
Mostrando 1-12 de 14 artigos, teses e dissertações.
-
1. The experience of community urban gardens: Social organization and food security
RESUMO Objetivo Caracterizar as hortas urbanas comunitárias de Salvador-Bahia, quanto à organização social, ao trabalho, à oferta e o acesso aos alimentos, em alinhamento ao conceito de Segurança Alimentar. Métodos Realizou-se estudo transversal, exploratório, envolvendo levantamento de informações, identificação e seleção das hortas comunit�
Rev. Nutr.. Publicado em: 12/09/2019
-
2. MigraÃÃo inter-regional no Brasil : determinantes e perfil do migrante brasileiro no perÃodo 1980-2000
A partir dos microdados dos Censos DemogrÃficos de 1980, 1991 e 2000, o trabalho descreve os padrÃes de migraÃÃo em vÃrias dimensÃes: inter-regional, interestadual, rural-urbano e urbanourbano. Em termos da migraÃÃo interestadual, Minas Gerais à o estado com maior participaÃÃo relativa na emissÃo de migrantes, embora, a participaÃÃo diminua ao
Publicado em: 2006
-
3. When does the good of the group override the advantage of the individual?
In a system of N populations of n reproductive individuals apiece, in which each population has constant variance v2 and lasts L generations, group selection on a quantitative character has a reasonable chance of overriding selection within populations if (and only if) the populations never exchange migrants, each population is founded by colonists from a si
-
4. Group selection on a quantitative character
We derive a model of group and individual selection on a quantitative character that is similar to the single-locus “metapopulation” models of group selection. Two alternative methods for the colonization of new or vacant habitats are examined and their effects are contrasted. In one model, all populations contribute migrants to a common pool, the “mig
-
5. Gene Flow and Selection in a Natural Population of DROSOPHILA MELANOGASTER
A marked genetic differentiation to the presence of alcohol in the environment has been shown to occur between inside cellar and adjacent outside sections of a vineyard population of D. melanogaster ( McKenzie and Parsons 1974). Estimates of migration during the vintage period suggest considerable movement occurs from outside into the cellar and that the mos
-
6. Genetic variation in a Pacific Island land snail: population history versus current drift and selection.
Previous studies of Partula land snails from the Society Islands, French Polynesia, have shown that there can be striking differences in shell shape, colour and banding pattern between nearby populations, even in the absence of any obvious geographical barriers to the movement of snails, or environmental gradients. Elsewhere, there may be relative uniformity
-
7. Group selection for a polygenic behavioral trait: a differential proliferation model.
Conditions for natural selection to increase a polygenic behavioral trait are derived for a model in which the population is divided into a very large number of partially isolated groups of variable and varying size. Specifically, we consider an altruistic trait that is deleterious to the individual but raises the mean fitness of the group. We assume, for ea
-
8. Bacillus thuringiensis-toxin resistance management: Stable isotope assessment of alternate host use by Helicoverpa zea
Data have been lacking on the proportion of Helicovera zea larvae that develop on noncotton host plants that can serve as a refuge from selection pressure for adaptation to transgenic cotton varieties that produce a toxin from the bacterium Bacillus thuringiensis. We found that individual H. zea moths that develop as larvae on cotton and other plants with C3
National Academy of Sciences.
-
9. Homozygosity, effective number of alleles, and interdeme differentiation in subdivided populations.
The amount and pattern of genetic variability in a geographically structured population at equilibrium under the joint action of migration, mutation, and random genetic drift is studied. The monoecious, diploid population is subdivided into panmictic colonies that exchange migrants. Self-fertilization does not occur; generations are discrete and nonoverlappi
-
10. Group selection for a polygenic behavioral trait: estimating the degree of population subdivision.
For assessing the degree of population subdivision, and therefore the extent to which group selection might favor an altruistic trait, an appropriate measure is Nei's GST, defined by (F0-F)/(1-F). F0 is the probability that two alleles drawn from the same group are identical in state and F is the probability for two alleles drawn at random from the entire po
-
11. Frequency of migrants and migratory activity are genetically correlated in a bird population: Evolutionary implications
Most migratory bird populations are composed of individuals that migrate and individuals that remain resident. While the role of ecological factors in maintaining this behavioral dimorphism has received much attention, the importance of genetic constraints on the evolution of avian migration has not yet been considered. Drawing on the recorded migratory
The National Academy of Sciences of the USA.
-
12. Co-evolution of KIR2DL3 with HLA-C in a human population retaining minimal essential diversity of KIR and HLA class I ligands
Natural killer (NK) cells contribute to immunity and reproduction. Guiding these functions, and NK cell education, are killer cell Ig-like receptors (KIR), NK cell receptors that recognize HLA class I. In most human populations, these highly polymorphic receptors and ligands combine with extraordinary diversity. To assess how much of this diversity is necess
National Academy of Sciences.