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Environmental Shift (environmental + shift)

Distribution by Scientific Domains

Humanities and Social Sciences	50%

Selected Abstracts

IS INBREEDING DEPRESSION LOWER IN MALADAPTED POPULATIONS?

EVOLUTION, Issue 7 2009
A QUANTITATIVE GENETICS MODEL
Despite abundant empirical evidence that inbreeding depression varies with both the environment and the genotypic context, theoretical predictions about such effects are still rare. Using a quantitative genetics model, we predict amounts of inbreeding depression for fitness emerging from Gaussian stabilizing selection on some phenotypic trait, on which, for simplicity, genetic effects are strictly additive. Given the strength of stabilizing selection, inbreeding depression then varies simply with the genetic variance for the trait under selection and the distance between the mean breeding value and the optimal phenotype. This allows us to relate the expected inbreeding depression to the degree of maladaptation of the population to its environment. We confront analytical predictions with simulations, in well-adapted populations at equilibrium, as well as in maladapted populations undergoing either a transient environmental shift, or gene swamping in heterogeneous habitats. We predict minimal inbreeding depression in situations of extreme maladaptation. Our model provides a new basis for interpreting experiments that measure inbreeding depression for the same set of genotypes in different environments, by demonstrating that the history of adaptation, in addition to environmental harshness per se, may account for differences in inbreeding depression. [source]

Collapse as Cultural Revolution: Power and Identity in the Tiwanaku to Pacajes Transition

ARCHEOLOGICAL PAPERS OF THE AMERICAN ANTHROPOLOGICAL ASSOCIATION, Issue 1 2004
John Wayne Janusek
Inherent foundations of power are often made explicit in state collapse and ethnogenesis, among the most problematic processes tackled by archaeologists. Recent research on collapse globally indicates that conventional models prioritizing external change (e.g., environmental shift, immigration) fail to address the historical intricacies of and human agency involved in state fragmentation. Some recent models treat collapse as a sudden drop in political complexity, and most fail to elaborate how state collapse influenced postcollapse sociopolitical and cultural patterns. Synthesizing substantial recent research on Tiwanaku (A.D. 500,1150) and post-Tiwanaku Pacajes (A.D. 1150,1450) polities in the south-central Andes, I suggest that state collapse involved a fateful conjunction of sociopolitical and environmental transformations. Drought conditions descended upon a centralized yet highly fragile sociopolitical landscape that had become increasingly volatile during Tiwanaku's apogee. Collapse involved rapid transformation as well as slow, cumulative shifts and enduring continuities. It was a cultural revolution that began during Tiwanaku hegemony and drew heavily on existing practices and ideals. Grounded in practice theory, this case study finds human agency squarely in the center of macroprocesses such as collapse and situates Andean foundations of power in the matrix of local ideals, practices, and identities from which hegemonic regimes such as Tiwanaku were forged. [source]

Changing household responses to drought in Tharaka, Kenya: vulnerability, persistence and challenge

DISASTERS, Issue 2 2008
Thomas A. Smucker
Drought is a recurring challenge to the livelihoods of those living in Tharaka District, Kenya, situated in the semi-arid zone to the east of Mount Kenya, from the lowest slopes of the mountain to the banks of the Tana River. This part of Kenya has been marginal to the economic and political life of Kenya from the colonial period until the present day. A study of more than 30 years of change in how people in Tharaka cope with drought reveals resilience in the face of major macro-level transformations, which include privatisation of landownership, population growth, political decentralisation, increased conflict over natural resources, different market conditions, and environmental shifts. However, the study also shows troubling signs of increased use of drought responses that are incompatible with long-term agrarian livelihoods. Government policy needs to address the challenge of drought under these new macro conditions if sustainable human development is to be achieved. [source]

A Contingency View of the Responses of Voluntary Social Service Organizations in Ontario to Government Cutbacks

CANADIAN JOURNAL OF ADMINISTRATIVE SCIENCES, Issue 1 2002
Mary K. Foster
Voluntary organizations in Ontario have been thrust into a new environment; government funding on which they have traditionally counted has been reduced to the extent that actions have to be taken in order for some organizations to survive. Using a sample of 85 from a mailed survey to voluntary social service organizations in Toronto, we collected information on how organizational characteristics are influencing the actions taken in the face of these changes. We found that the alternatives considered factored into five dimensions: enhancing the image of the organization; cutting costs; developing strategic plans and accountability; implementing new tactics, such as user fees; and restructuring the governance and management structure. Analysis showed that younger organizations, smaller-sized agencies, and those with a diverse set of funding sources employ a wider range of options to deal with environmental challenges. Many of these options are directed at protecting the main mission of the organization and building awareness and marketing strength so that the organization reduces its susceptibility to environmental shifts. Résumé Les organismes de bénévolat de l'Ontario sont plongés dans un nouveau contexte, car les subventions gouvernementales sur lesquelles ils comptaient jusqu'à présent sont réduites à un point tel que des mesures doivent être prises afin qu'ils puissent survivre. Un sondage effectué par la poste auprès de 85 organismes de services sociaux bénévoles de Toronto nous a permis de rassembler des données montrant que certaines caractéristiques organisationnelles peuvent influencer les mesures à prendre face à de tels changements, et nous avons envisagé cinq solutions possibles pour remédier à la situation: rehausser l'image de ces organismes; réduire leurs coûts; mettre sur pied certaines stratégies et rendre compte de leurs activités; utiliser de nouvelles tactiques, tels des frais d'utilisation; ainsi qu'en restructurer l'administration et la gestion. Il ressort de cette analyse que les organismes plus récents et de plus petite taille ainsi que ceux bénéficiant de sources de financement plus variées peuvent utiliser un plus vaste ventail d'options pour contrer les difficultés que présente la conjoncture actuelle. La plupart de ces possibilités visent à préserver la mission principale de ces organismes et à renforcer leur vision et leur politique de marketing afin de réduire leur vulnérabilité face à tout changement conjoncturel. [source]