Genomic architecture of adaptive color pattern divergence and convergence in Heliconius butterflies

Identifying the genetic changes driving adaptive variation in natural populations is key to understanding the origins of biodiversity. The mosaic of mimetic wing patterns in Heliconius butterflies makes an excellent system for exploring adaptive variation using next-generation sequencing. In this study, we use a combination of techniques to annotate the genomic interval modulating red color pattern variation, identify a narrow region responsible for adaptive divergence and convergence in Heliconius wing color patterns, and explore the evolutionary history of these adaptive alleles. We use whole genome resequencing from four hybrid zones between divergent color pattern races of Heliconius erato and two hybrid zones of the co-mimic Heliconius melpomene to examine genetic variation across 2.2 Mb of a partial reference sequence. In the intergenic region near optix, the gene previously shown to be responsible for the complex red pattern variation in Heliconius, population genetic analyses identify a shared 65-kb region of divergence that includes several sites perfectly associated with phenotype within each species. This region likely contains multiple cis-regulatory elements that control discrete expression domains of optix. The parallel signatures of genetic differentiation in H. erato and H. melpomene support a shared genetic architecture between the two distantly related co-mimics; however, phylogenetic analysis suggests mimetic patterns in each species evolved independently. Using a combination of next-generation sequencing analyses, we have refined our understanding of the genetic architecture of wing pattern variation in Heliconius and gained important insights into the evolution of novel adaptive phenotypes in natural populations.

Residential Mobility: a Sociological Concern

The aim of this paper is to present a theoretical-conceptual approach to residential mobility, in general, and residential trajectories, in particular. It seeks to understand how from the unequal distribution and appropriation of social resources —both material and symbolic— different trajectories are developed and how socio-territorial structures constrain, shape and enable interactions between families, their members and the various contexts of action towards meeting their housing needs. From sociological contributions of different traditions, we present a scheme that pays attention to articulating the relationship between structural factors, position in social structure and decisions elating to changes of residence. We conclude that mobility patterns are relational patterns that are defined in dialogue with the opportunities and limitations that are set up around the housing stock and new or vacant land, the land market dynamics and housing, the labor market, the provision of nfrastructure services and social facilities, etc.

Social housing and land use planning in Medellin during the period 2006-2011. Steps towards socio economic and residential segregation

This paper presents an approach to the relationship between land use planning and socioeconomic residential segregation, from the location of social housing in Medellin, Colombia, during the period 2006-2011. The first part introduces the land use regulations regarding the location of social housing, identifying ambiguities in the current spatial plan. Next, we present the intersection of  regulatory information and the location of the projects that were under construction during the  study period, highlighting the need to consider the location as an important characteristic of social housing and residential segregation as a phenomenon that must be recognized and worked on land  use planning in our cities.

Comparación de las dinámicas de uso y apropiación del espacio público en parques de origen informal y formal: parque Villa de la Torre y parque Cayetano Cañizares

El interés de este estudio de caso es comparar las dinámicas de uso y apropiación del espacio público en parques de origen formal e informal, y discutir sus implicaciones en la vida social y urbana, teniendo como zonas el parque Villa de la Torre (informal) y el parque Cayetano Cañizares (formal). Este trabajo se enmarca en conceptos de uso y apropiación del espacio público, a partir de los cuales se examinan las dinámicas de formalidad e informalidad de los parques zonas de estudio, explorando qué efectos puede tener su origen, y revisando si el parque informal implica falta de apropiación y usos conflictivos, o si por el contrario, las dinámicas que en espacios públicos se dan pueden incluir dinámicas positivas y negativas indistintamente de su origen.