Cattle Raiding, Cultural Survival, and Adaptability of East African Pastoralists

This is the published version. Also found here http://www.jstor.org/stable/359710

Cattle Raiding, Cultural Survival, and Adaptability of East African Pastoralists

This is the published version. Also found here http://www.jstor.org/stable/359710

Genetics of decayed sexual traits in a parasitoid wasp with endosymbiont-induced asexuality.

Trait decay may occur when selective pressures shift, owing to changes in environment or life style, rendering formerly adaptive traits non-functional or even maladaptive. It remains largely unknown if such decay would stem from multiple mutations with small effects or rather involve few loci with major phenotypic effects. Here, we investigate the decay of female sexual traits, and the genetic causes thereof, in a transition from haplodiploid sexual reproduction to endosymbiont-induced asexual reproduction in the parasitoid wasp Asobara japonica. We take advantage of the fact that asexual females cured of their endosymbionts produce sons instead of daughters, and that these sons can be crossed with sexual females. By combining behavioral experiments with crosses designed to introgress alleles from the asexual into the sexual genome, we found that sexual attractiveness, mating, egg fertilization and plastic adjustment of offspring sex ratio (in response to variation in local mate competition) are decayed in asexual A. japonica females. Furthermore, introgression experiments revealed that the propensity for cured asexual females to produce only sons (because of decayed sexual attractiveness, mating behavior and/or egg fertilization) is likely caused by recessive genetic effects at a single locus. Recessive effects were also found to cause decay of plastic sex-ratio adjustment under variable levels of local mate competition. Our results suggest that few recessive mutations drive decay of female sexual traits, at least in asexual species deriving from haplodiploid sexual ancestors

Genetics of decayed sexual traits in a parasitoid wasp with endosymbiont-induced asexuality

Trait decay may occur when selective pressures shift, owing to changes in environment or life style, rendering formerly adaptive traits non-functional or even maladaptive. It remains largely unknown if such decay would stem from multiple mutations with small effects or rather involve few loci with major phenotypic effects. Here, we investigate the decay of female sexual traits, and the genetic causes thereof, in a transition from haplodiploid sexual reproduction to endosymbiont-induced asexual reproduction in the parasitoid wasp Asobara japonica. We take advantage of the fact that asexual females cured of their endosymbionts produce sons instead of daughters, and that these sons can be crossed with sexual females. By combining behavioral experiments with crosses designed to introgress alleles from the asexual into the sexual genome, we found that sexual attractiveness, mating, egg fertilization and plastic adjustment of offspring sex ratio (in response to variation in local mate competition) are decayed in asexual A. japonica females. Furthermore, introgression experiments revealed that the propensity for cured asexual females to produce only sons (because of decayed sexual attractiveness, mating behavior and/or egg fertilization) is likely caused by recessive genetic effects at a single locus. Recessive effects were also found to cause decay of plastic sex-ratio adjustment under variable levels of local mate competition. Our results suggest that few recessive mutations drive decay of female sexual traits, at least in asexual species deriving from haplodiploid sexual ancestors

Genetics of decayed sexual traits in a parasitoid wasp with endosymbiont-induced asexuality

Trait decay may occur when selective pressures shift, owing to changes in environment or life style, rendering formerly adaptive traits non-functional or even maladaptive. It remains largely unknown if such decay would stem from multiple mutations with small effects or rather involve few loci with major phenotypic effects. Here, we investigate the decay of female sexual traits, and the genetic causes thereof, in a transition from haplodiploid sexual reproduction to endosymbiont-induced asexual reproduction in the parasitoid wasp Asobara japonica. We take advantage of the fact that asexual females cured of their endosymbionts produce sons instead of daughters, and that these sons can be crossed with sexual females. By combining behavioral experiments with crosses designed to introgress alleles from the asexual into the sexual genome, we found that sexual attractiveness, mating, egg fertilization and plastic adjustment of offspring sex ratio (in response to variation in local mate competition) are decayed in asexual A. japonica females. Furthermore, introgression experiments revealed that the propensity for cured asexual females to produce only sons (because of decayed sexual attractiveness, mating behavior and/or egg fertilization) is likely caused by recessive genetic effects at a single locus. Recessive effects were also found to cause decay of plastic sex-ratio adjustment under variable levels of local mate competition. Our results suggest that few recessive mutations drive decay of female sexual traits, at least in asexual species deriving from haplodiploid sexual ancestors

Documenting the health consequences of endemic warfare in three pastoralist communities of northern Kenya: A conceptual framework

Violent conflict represents the third most important source of mortality around the world, yet violence-related mortality remains profoundly undercounted (Krug, Dahlberg, Mercy, Zwi, & Lozano, 2002). As a step toward documenting the consequences of even the "smallest wars" we offer a conceptual framework for a recently initiated project that comparatively examines the direct and indirect consequences of intercommunity violence among Pokot, Samburu, and Turkana herding communities of Northern Kenya. While a substantial body of work has accumulated on the social responses to this violence very little is known about the differential impacts on community health. Based on our cumulative ethnographic experience in the area, we offer a conceptual framework that merges a context-sensitive ethnographic approach with a comparative epidemiological one centered on documenting the lived experience of violence and inequality. In this paper, we provide evidence for the importance of a contextualized approach detailing how social environments that include chronic episodes of violence produce variations in health. We do so by presenting the results of previous work to highlight what is known and follow this by identifying what remains to be understood about how violence, inequality, and health interact in these communities. While much is known about the importance of access to livestock herds for health, nutrition, and child growth in this difficult physical environment, far less is known about how the social responses to violence interact with access to herds to create new patterns of nutrition and health. With respect to pastoralists, additional areas that remain only nominally understood include age-specific mortality patterns, reproductive health, and psychosocial/mental health, topics that we view as central to the current study. In sum, we suggest that health offers one of the most useful tools for examining the costs of violence by creating opportunities for advocacy.Endemic warfare Social production of health Embodiment Ethnicity Nomadic pastoralism Violence