Sex-specific local life-history adaptation in surface- and cave-dwelling Atlantic mollies (Poecilia mexicana)

Cavefishes have long been used as model organisms showcasing adaptive diversification, but does adaptation to caves also facilitate the evolution of reproductive isolation from surface ancestors? We raised offspring of wild-caught surface- and cave-dwelling ecotypes of the neotropical fish Poecilia mexicana to sexual maturity in a 12-month common garden experiment. Fish were raised under one of two food regimes (high vs. low), and this was crossed with differences in lighting conditions (permanent darkness vs. 12:12 h light:dark cycle) in a 2 × 2 factorial design, allowing us to elucidate potential patterns of local adaptation in life histories. Our results reveal a pattern of sex-specific local life-history adaptation: Surface molly females had the highest fitness in the treatment best resembling their habitat of origin (high food and a light:dark cycle), and suffered from almost complete reproductive failure in darkness, while cave molly females were not similarly affected in any treatment. Males of both ecotypes, on the other hand, showed only weak evidence for local adaptation. Nonetheless, local life-history adaptation in females likely contributes to ecological diversification in this system and other cave animals, further supporting the role of local adaptation due to strong divergent selection as a major force in ecological speciation

Social network analysis resolves temporal dynamics of male dominance relationships

Social organization is often studied through point estimates of individual association or interaction patterns, which does not account for temporal changes in the course of familiarization processes and the establishment of social dominance. Here, we present new insights on short-term temporal dynamics in social organization of mixed-sex groups that have the potential to affect sexual selection patterns. Using the live-bearing Atlantic molly (Poecilia mexicana), a species with pronounced male size polymorphism, we investigated social network dynamics of mixed sex experimental groups consisting of eight females and three different-sized males over a period of 5 days. Analyzing association-based social networks as well as direct measures of spatial proximity, we found that large males tended to monopolize most females, while excluding small- and medium-bodied males from access to females. This effect, however, emerged only gradually over time, and different-sized males had equal access to females on day 1 as well as day 2, though to a lesser extent. In this highly aggressive species with strong social dominance stratifications, the observed temporal dynamics in male-female association patterns may balance the presumed reproductive skew among differentially competitive male phenotypes when social structures are unstable (i.e., when individual turnover rates are moderate to high). Ultimately, our results point toward context-dependent sexual selection arising from temporal shifts in social organization. © 2014 Springer-Verlag Berlin Heidelberg

Gauging knowledge of developmental milestones among Albertan adults: a cross-sectional survey

<p>Abstract</p> <p>Background</p> <p>Parental knowledge of child development has been associated with more effective parenting strategies and better child outcomes. However, little is known about what adults who interact with children under the age of 14 years know about child development.</p> <p>Methods</p> <p>Between September 2007 and March 2008, computer assisted telephone interviews were completed with 1443 randomly selected adults. Adults were eligible if they had interacted with a child less than 14 years of age in the past six months and lived in Alberta, Canada.</p> <p>Results</p> <p>Sixty three percent of respondents answered two (or more) out of four questions on physical development correctly. Fifteen percent of respondents answered two (or more) out of three questions on cognitive development correctly. Seven percent of respondents answered three (or more) out of five questions on social development correctly. Two percent of respondents answered three (or more) out of five questions on emotional development correctly. Parents and females were better able to identify physical developmental milestones compared to non-parents and males. 81% of adults correctly responded that a child's experience in the first year of life has an important impact on later school performance, 70% correctly responded that a child's ability to learn is not set from birth, 50% of adults correctly responded that children learn more from hearing someone speak than from television, and 45% recognized that parents' emotional closeness with a baby influences later achievement. Parents were most likely to use doctors/paediatricians, books, and nurses as resources. Among parents, there was no relationship between knowledge and parenting morale.</p> <p>Conclusions</p> <p>The majority of adults were unable to correctly answer questions related to when children under six years of age typically achieve developmental milestones. Knowledge of physical development exceeded knowledge about cognitive, emotional and social development. Adults were aware of the importance of positive experiences in influencing children's development. Strategies to improve awareness of developmental milestones combined with information on how to support optimal development may improve child development outcomes. Given that parents seek information about child development from health care providers there is an opportunity to ensure that providers are well informed about child development.</p