2009年11月5日 星期四

奇貨不一定可居 - 藍鰭盧氏鱂雄性色彩多態性的維持無法完全以負向依頻理論解釋

文獻來源: Fuller RC, Johnson AM. 2009. A test for negative frequency-dependent mating success as a function of male colour pattern in the bluefin killifish. Biological Journal of the Linnean Society 98(3): 489-500.

Abstract
Rare male mating advantage (a form of negative frequency dependence) is frequently proposed as a mechanism for the maintenance of genetic variation within populations. This hypothesis is attractive for systems with pronounced male colour polymorphism because it can maintain particularly high levels of variation. We tested for negative frequency-dependent mating success between yellow and red male colour patterns in bluefin killifish, Lucania goodei. Lucania goodei populations harbour substantial colour pattern polymorphism, and a large proportion of this variation has a genetic basis. We established outdoor mesocosms with red and yellow males in three different ratios: yellow rare (one yellow ♂ : five red ♂), even (three yellow ♂ : three red ♂), and red rare (five yellow ♂ : one red ♂). We obtained eggs and used microsatellites to determine paternity. By contrast to expectations, we found no support for a rare male mating advantage. Red males had slightly higher spawning success than yellow males, particularly in replicates with large clutches and when red males were rare. However, yellow males did not have higher mating success when rare. We discuss alternative mechanisms for the maintenance of the polymorphism as well as the potential reasons for the lack of a rare male mating advantage.

圖片連結: http://www.hippocampus-bildarchiv.de/images/N61605_Lucania_goodei.jpg