PREJUDICE REDUCTION STRATEGIES AND THEIR EFFFECT ON INTERRACIAL INTERACTIONS

With increased awareness of implicit bias in both research and media, understanding ways to reduce the negative effects of such bias has become of practical importance. The present research examined how implicit bias reduction strategies affect the experience of an implied interracial interaction. Results indicated that self-regulation learning (SRL) and counterstereotyping (CS) differentially impact how individuals experience an interracial interaction depending on their internal motivation to respond without prejudice (IMS). Specifically, results showed that individuals low in IMS self-disclosed more, were more promotion focused, and less physically avoidant following CS training relative to SRL training. At high levels of IMS, however, individuals self-disclosed more, were more promotion focused, and less physically avoidant following SRL training relative to CS. This evidence suggests that the specific processes involved in training strategies interact with IMS to differentially impact interracial interactions. Implications for future research and prejudice interventions are discussed

The effect of habitat and body size on the evolution of vocal displays in Thraupidae (tanagers), the largest family of songbirds

© 2015 The Linnean Society of London. Animals rely on auditory cues to relay important information between individuals regarding territoriality, mating status, and individual condition. The efficacy of acoustic signals can depend on many factors, including the transmitter, the receiver, and the signalling environment. In the present study, we evaluate the effect of body size and habitat on the evolution of learned vocal displays across the tanagers (Aves: Thraupidae), a group that comprises nearly 10% of all songbird species. We find that body size affects tanager vocalizations, such that nine out of ten song characters and scores from two principal component axes were correlated with mass. More specifically, larger tanagers tended to produce slower-paced, lower-pitched vocal displays within narrower bandwidths. In contrast, habitat was correlated with only three out of ten song characters, and only one of these characters corroborated the directional predictions of the acoustic adaptation hypothesis. Thus, morphological characters, such as body mass, may play a more important role than variation among signalling environments in the evolution of avian vocal displays

Elaborate visual and acoustic signals evolve independently in a large, phenotypically diverse radiation of songbirds

The concept of a macroevolutionary trade-off among sexual signals has a storied history in evolutionary biology. Theory predicts that if multiple sexual signals are costly for males to produce or maintain and females prefer a single, sexually selected trait, then an inverse correlation between sexual signal elaborations is expected among species. However, empirical evidence for what has been termed the \u27transfer hypothesis\u27 is mixed, which may reflect different selective pressures among lineages, evolutionary covariates or methodological differences among studies. Here,we examine interspecific correlations between song and plumage elaboration in a phenotypically diverse, widespread radiation of songbirds, the tanagers. The tanagers (Thraupidae) are the largest family of songbirds, representing nearly 10% of all songbirds. We assess variation in song and plumage elaboration across 301 species, representing the largest scale comparative study of multimodal sexual signalling to date. We consider whether evolutionary covariates, including habitat, structural and carotenoid-based coloration, and subfamily groupings influence the relationship between song and plumage elaboration. We find that song and plumage elaboration are uncorrelated when considering all tanagers, although the relationship between song and plumage complexity varies among subfamilies. Taken together, we find that elaborate visual and vocal sexual signals evolve independently among tanagers. © 2014 The Authors Published by the Royal Society. All rights reserved

Song evolution, speciation, and vocal learning in passerine birds

Phenotypic divergence can promote reproductive isolation and speciation, suggesting a possible link between rates of phenotypic evolution and the tempo of speciation at multiple evolutionary scales. To date, most macroevolutionary studies of diversification have focused on morphological traits, whereas behavioral traits─including vocal signals─are rarely considered. Thus, although behavioral traits often mediate mate choice and gene flow, we have a limited understanding of how behavioral evolution contributes to diversification. Furthermore, the developmental mode by which behavioral traits are acquired may affect rates of behavioral evolution, although this hypothesis is seldom tested in a phylogenetic framework. Here, we examine evidence for rate shifts in vocal evolution and speciation across two major radiations of codistributed passerines: one oscine clade with learned songs (Thraupidae) and one suboscine clade with innate songs (Furnariidae). We find that evolutionary bursts in rates of speciation and song evolution are coincident in both thraupids and furnariids. Further, overall rates of vocal evolution are higher among taxa with learned rather than innate songs. Taken together, these findings suggest an association between macroevolutionary bursts in speciation and vocal evolution, and that the tempo of behavioral evolution can be influenced by variation in developmental modes among lineages

Genetic variation among western populations of the Horned Lark (Eremophila alpestris) indicates recent colonization of the Channel Islands off southern California, mainland-bound dispersal, and postglacial range shifts

© 2014 American Ornithologists\u27 Union. The Channel Islands off the coast of southern California host \u3e50 species of terrestrial vertebrates with varying degrees of phenotypic differentiation. However, most organisms that breed on the Channel Islands remain unstudied with respect to genetic differentiation from mainland populations. By comparing patterns of genetic variation between the Channel Islands and the mainland, we aimed to further our understanding of the role that the Channel Islands have played in diversification of the North American biota. We evaluated long-standing, untested hypotheses regarding colonization patterns and evolutionary relationships among western populations of the Horned Lark (Eremophila alpestris), including the endemic Channel Island subspecies E. a. insularis. We also examined how many times Horned Larks have colonized the Channel Islands, whether the species exhibits asymmetrical patterns of gene flow between mainland and island populations, and whether E. a. strigata of the Pacific Northwest is closely related to the phenotypically similar, but geographically separated, island subspecies. We found that E. a. insularis is polyphyletic, which suggests either multiple colonization events from the mainland or incomplete lineage sorting of a large ancestral population. We also inferred higher rates of migration from the Channel Islands to the mainland, with E. a. strigata being closely related to individuals from the Channel Islands and coastal southern California. Moreover, ecological niche models for E. a. strigata identified suitable abiotic conditions in southern California and the Pacific Northwest during the Last Glacial Maximum, which suggests that E. a. strigata experienced a postglacial range shift in addition to a population bottleneck. Our results provide novel insight regarding the origins of the Channel Island avifauna and the evolutionary history of the Horned Lark in the western United States. Moreover, our findings suggest that Channel Island birds may be weakly differentiated from mainland populations despite phenotypic differences between recognized subspecies

Managing the trade-off implications of global supply

The cost versus response trade-off is a growing logistics issue due to many markets being increasingly characterized by demand uncertainty and shorter product life cycles. This is exacerbated further with supply increasingly moving to low cost global sources. However, the poor response implications of global supply are often not addressed or even acknowledged when undertaking such decisions. Consequently, various practical approaches to minimising, postponing or otherwise managing the impact of the demand uncertainty are often only adopted retrospectively. Even though such generic solutions are documented through case examples we lack effective tools and concepts to support the proactive identification and resolution of such trade-offs. This paper reports on case-based theory building research, involving three cases from the UK and USA used in developing a conceptual model with associated tools, in support of such a process