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Low-density rural home development is the fastest-growing form of land use in the United States since 1950. This ''exurban'' development (ϳ6–25 homes/km 2) includes urban fringe development (UFD) on the periphery of cities and rural residential development (RRD) in rural areas attractive in natural amenities. This paper synthesizes current knowledge on the(More)
A new real-time IIR filter s t r u c t u r e is presented t h a t possesses exact phase linearity with 10-1000 times fewer general multiplies t h a n conventional FIR filters of similar performance a n d better magnitude characteristics t h a n equiripple o r maximally flat g r o u p delay IIR filters. This s t r u c t u r e is based on a novel technique(More)
Many insects and arthropods live in colonies or aggregations of varying size. Group size may affect collective organization either because the same individual behavior has different consequences when displayed in a larger group or because larger groups are subject to different constraints and selection pressures than smaller groups. In eusocial colonies,(More)
1. Arboreal ants are both diverse and ecologically dominant in the tropics. Such ecologically important groups are likely to be particularly useful in ongoing empirical efforts to understand the processes that regulate species diversity and coexistence. 2. Our study addresses how access to tree-based resources and the diversity of pre-existing nesting(More)
  • S Powell
  • 2009
Caste evolution is a central process in the adaptive diversification of insect superorganisms. Nevertheless, how ecology shapes adaptive caste evolution remains poorly understood. Recent work with the ant genus Cephalotes has provided new comparative evidence that ecological specialization may drive adaptive caste specialization. Here, three key predictions(More)
Intracolonial conflict among ant workers can establish a reproductive hierarchy, with top-ranking individuals often securing oviposition opportunities. Here we show that in the ant Odontomachus brunneus, reproduction-based dominance interactions control worker movement and location, and that this, in turn, mechanistically governs task allocation within the(More)
Correlation between gut microbiota and host phylogeny could reflect codiversification over shared evolutionary history or a selective environment that is more similar in related hosts. These alternatives imply substantial differences in the relationship between host and symbiont, but can they be distinguished based on patterns in the community data(More)
Ecological opportunity, defined as access to new resources free from competitors, is thought to be a catalyst for the process of adaptive radiation. Much of what we know about ecological opportunity, and the larger process of adaptive radiation, is derived from vertebrate diversification on islands. Here, we examine lineage diversification in the turtle(More)
In a recent study, Denny et al. (2004a) showed that queens of the army ant, Eciton burchellii, mate with multiple males and presented estimates suggesting that they mate with more males than queens of any other ant species so far investigated. They also inferred that data were consistent with queens being inseminated repeatedly throughout their life, which(More)
Individual specialization underpins the division of labour within ant societies, but only in a small minority do morphological specialists, or physical castes, exist in the workforce. The genetic conditions that allow such castes to evolve are well understood, but the ecological pressures that select for them are not. We provide compelling evidence that the(More)