Whither the ‘socially isolated’ city?

This article analyses William J. Wilson’s use of the concept of social isolation in studying the urban poor. It traces the origins of Wilson’s use of the concept in human ecology, focusing upon critical aspects of the ‘socially isolated’ city and its influence upon ethnographies of the urban poor. His particular focus is upon the interaction of the poor with the mainstream. While Wilson places considerable emphasis upon the role of the state, those appropriating his concept have not adequately incorporated government institutions and discourse into their analyses of culture and practice.     

Social isolation,and concentration effects: William Julius Wilson ­revisited and re-applied

Two concepts employed by William Julius Wilson in his effort to advance scholarship on race and urban poverty in America are social isolation and concentration effects. These concepts help comprise a conceptual scheme that provides an alternative lens to that which centres on the behaviour of the urban poor as the principal source of their troubled lives. This article elucidates a research agenda that asserts that the impact of social isolation and concentration effects extends beyond measures of distance or proximity to institutions and individuals that can enable greater efficacy for the urban poor. Rather, social isolation and the concentration of disadvantaged people within bounded geographic regions also facilitates serial patterns of social contact and exposure that become crucial factors for how people construct interpretations of social reality. These interpretations are crucial factors for initiating (or, in some cases, inhibiting) individual action on the part of the urban poor.     

How should we study social suffering?

This commentary argues that intellectual fragmentation is not only bad for the study of poverty, prejudice and penalty; it is bad for the problems themselves. Considering new objects of analysis for research on inequality – that is, critically reconsidering what it is that we should be studying in the first place – is proposed as a viable preventative to academic parochialism and overspecialization.     

‘Culture shock’: Black students account for their distinctiveness at an elite college

Previous research on black students attending predominantly white colleges has emphasized race-based differences with white students while downplaying differences in social class. This research indicates that class-based differences are an important component of many black students’ discomfort at ‘Northern College’, a school that has traditionally served wealthy white students. Drawing on interviews and participant observation done on campus, I apply cultural capital theory to explain how differences in class-specific cultural styles make campus life difficult for non-affluent blacks and discuss the implications of the findings for future research on black college experiences.     

Evolution of maternal care in diploid and haplodiploid populations

Maternal care has been suggested to evolve more readily in haplodiploid populations. Because maternal care appears to have been a prerequisite for the evolution of eusociality, this effect potentially explains the apparent preponderance of haplodiploidy among eusocial taxa. Here, I use a kin selection approach to model the evolution of maternal care in diploid and haplodiploid populations. In contrast to previous suggestions, I find that haplodiploidy may inhibit as well as promote the evolution of maternal care. Moreover, I find that the haplodiploidy effect vanishes in outbred populations if gene effects average rather than add together. I confirm these analytical results using numerical simulation of an explicit population genetics model. This analysis casts doubt upon the idea that haplodiploidy has promoted the evolution of maternal care and, consequently, the evolution of eusociality.     

Assemblage-level responses of phyllostomid bats to tropical forest fragmentation: land-bridge islands as a model system

Aim Working within a system of high structural contrast between fragments and the surrounding matrix, we assessed patterns of species loss and changes in species composition of phyllostomid bats on artificial land‐bridge islands relative to mainland assemblages, and evaluated the responses of bats to forest edges. We further examined the relative influence of local‐scale characteristics (e.g. vegetation structure, island area) versus landscape attributes (e.g. forest cover, patch density) and the importance of spatial scale in determining phyllostomid species richness and composition on islands. Location Islands in Gatún Lake and adjacent mainland peninsulas in the Barro Colorado Nature Monument, Panama. Methods Bats were sampled over a 2‐year period on 11 islands as well as at forest‐edge and interior sites on adjacent mainland, resulting in > 8400 captures. Results The islands harboured a less diverse and structurally simplified phyllostomid bat fauna. Islands far from the mainland were especially species‐poor. This decline in species richness was associated with compositional shifts towards assemblages strongly dominated by frugivores with good dispersal abilities. Members of other ensembles, most importantly gleaning animalivores, were much less common or absent. Although overall species composition was not significantly altered, species richness at continuous forest‐edge sites was significantly lower compared with that at interior sites. Distance from the mainland and amount of forest cover in the landscape were the best predictors of species richness and assemblage composition. Responses were scale‐dependent. At the local scale, species richness was independent of island area but was correlated positively with distance from the mainland. In contrast, area effects became more important at larger spatial scales, suggesting that many species use multiple fragments. Main conclusions Our results underline the conservation value of small habitat remnants, which, even when embedded in a hostile matrix, can support a relatively diverse bat fauna, provided that there is a low degree of patch isolation and spatial proximity to larger tracts of continuous forest. Although the results at the assemblage level were inconclusive, we demonstrate that certain bat species and ensembles, particularly gleaning animalivores, exhibit high edge‐sensitivity. Our results point to habitat loss rather than changes in landscape configuration as the main process after isolation underlying phyllostomid bat responses, suggesting that conservation efforts should focus on habitat preservation instead of trying to minimize fragmentation per se at the expense of habitat amount.