Skroblin A, Blows M W
School of Integrative Biology, University of Queensland, St Lucia, QLD, Australia.
J Evol Biol. 2006 Jan;19(1):35-41. doi: 10.1111/j.1420-9101.2005.00986.x.
Fundamental to many theories of sexual selection is the expectation that sexual traits, which males use in an attempt to increase mating success, confer costs as well as benefits to individual males. Although evolution of exaggerated male traits is predicted to be halted, by costs applied by natural selection, there is a lack of empirical work devoted to quantitatively establishing whether natural selection opposes sexual selection generated by the preferences of females. In this study, we quantified natural and sexual selection gradients on breeding values for cuticular hydrocarbon (CHC) components of male contact pheromones in Drosophila serrata. As male sexual traits may often be environmentally condition dependent, breeding values were used in the selection analysis to remove the possibility of environmental correlations between the measured trait and fitness biasing estimates of selection. The direction of natural selection was found to oppose sexual selection on a subset of CHCs examined. Opposing natural and sexual selection suggests that further evolution of the male pheromone may in part be limited by costs associated with attractive male CHC blends.
雄性用于提高交配成功率的性特征，给个体雄性带来的不仅有好处，也有代价。虽然预计自然选择施加的代价会阻止夸张雄性特征的进化，但缺乏专门用于定量确定自然选择是否反对由雌性偏好产生的性选择的实证研究。在本研究中，我们量化了锯谷盗雄性接触性信息素的表皮碳氢化合物（CHC）成分育种值上的自然选择和性选择梯度。由于雄性性特征可能常常依赖于环境条件，所以在选择分析中使用育种值以消除所测性状与适应性之间的环境相关性对选择估计产生偏差的可能性。研究发现，在所检测的一部分CHC上，自然选择的方向与性选择相反。自然选择和性选择相反表明，雄性信息素的进一步进化可能部分受到与有吸引力的雄性CHC混合物相关的代价的限制。
