Friday, August 11, 2017

Reproductive mode and the shifting arenas of evolutionary conflict

Furness, A. I., Morrison, K. R., Orr, T. J., Arendt, J. D. and Reznick, D. N. (2015), Reproductive mode and the shifting arenas of evolutionary conflict. Ann NY Acad Sci, 1360: 75–100. doi:10.1111/nyas.12835

Abstract: In sexually reproducing organisms, the genetic interests of individuals are not perfectly aligned. Conflicts among family members are prevalent since interactions involve the transfer of limited resources between interdependent players. Intrafamilial conflict has traditionally been considered along three major axes: between the sexes, between parents and offspring, and between siblings. In these interactions, conflict is expected over traits in which the resulting phenotypic value is determined by multiple family members who have only partially overlapping fitness optima. We focus on four major categories of animal reproductive mode (broadcast spawning, egg laying, live bearing, and live bearing with matrotrophy) and identify the shared phenotypes or traits over which conflict is expected, and then review the empirical literature for evidence of their occurrence. Major transitions among reproductive mode, such as a shift from external to internal fertilization, an increase in egg-retention time, modifications of embryos and mothers for nutrient transfer, the evolution of postnatal parental care, and increased interaction with the kin network, mark key shifts that both change and expand the arenas in which conflict is played out.

Rolf Degen's Comments: https://plus.google.com/101046916407340625977/posts/DdWUNNsnKxJ





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The effects of sex drive and paraphilic interests on paraphilic behaviours in a nonclinical sample of men and women

The effects of sex drive and paraphilic interests on paraphilic behaviours in a nonclinical sample of men and women. Katrina N. Bouchard, Samantha J. Dawson and Martin L. Lalumière.  The Canadian Journal of Human Sexuality, http://www.utpjournals.press/doi/abs/10.3138/cjhs.262-a8

Abstract: Research on samples of men and women from the general population suggests that paraphilic interests and behaviours are more common in men than in women, but the reasons for this sex difference are unclear. In addition, there is little research on how paraphilic interests lead to engagement in paraphilic behaviours. In this study, we assessed the frequency of engagement in a broad range of paraphilic behaviours in a nonclinical sample of men and women. We expected that men would report engaging in paraphilic behaviours more frequently than women. We also examined whether sex drive explained the sex difference in the frequency of engagement in paraphilic behaviours, as well as whether the relationship between paraphilic interests and frequency of engagement in paraphilic behaviours was stronger at high levels of sex drive. A sample of 305 men and 710 women completed an online survey assessing paraphilic interests and behaviours as well as three measures of sex drive. As expected, sex differences were found, with men reporting more frequent engagement in most paraphilic behaviours. After controlling for socially desirable responding, sex drive fully accounted for the male-biased sex differences. One measure of sex drive–the Sexual Behaviour and Desire Questionnaire–moderated the relationship between paraphilic interests and frequency of engagement in paraphilic behaviours, such that paraphilic interests were most strongly associated with paraphilic behaviours at high levels of sex drive. Taken together, these findings provide further support for the importance of sex drive in understanding the paraphilias.

KEY WORDS: Nonclinical sample, paraphilic behaviours, paraphilic interests, sex differences, sex drive


CEO Turnover and Political Repositioning

CEO Turnover and Political Repositioning. Yosef Bonaparte. University of Colorado Working Paper, June 2017, https://ssrn.com/abstract=2991032

Abstract: This paper examines the relation between political regime change, a new president from a new party, and propensity for CEO turnover. Our key conjecture is that some companies, especially those that are politically sensitive, will politically reposition to adapt to the new political regime, and this political repositioning will be reflected in increased CEO turnover. We find support for this hypothesis, for CEO turnover is at least 24% more likely to happen following political regime change. The economic significance of this CEO political repositioning varies by company characteristics, with repositioning greater among large cap stocks, stocks held by short term investors, and sectors that are politically sensitive. However, political repositioning decreases stock performance relative to the sector, though this effect is weakly significant. These results suggest that political regime change causes firms to reevaluate the required skills of the CEO. Collectively, we find that political repositioning is an important determinant of CEO turnover.

Keywords: CEO turnover and political repositioning
JEL Classification: G02, G11, G12