Dissertation Research: Theoretical and Experimental Investigations of Fisher's Sex Ratio Theory

R.A.Fisher首先提出，在对男性和女性投资相等的种群中，存在着一种选择机制，用于进化出男性和女性各占一半的性别比例。尽管费舍尔提出的原则被广泛接受，但没有人提供支持它们的测试结果。这一理论的实验测试对基础科学研究很重要，但它需要一个性别比具有遗传变异的动物系统。在热带淡水鱼剑鱼中发现了这种类型的变异，这种鱼有三条性染色体(W，X，Y)。这项实验将研究性别比不是1/2的贝类种群的性别比从一代到下一代的变化。结果将与计算机模拟预测的结果进行比较。该项目将提供可量化的结果，支持普遍接受的性别比进化理论。这项研究不仅对基础科学具有重要意义，而且在水产养殖中也具有潜在的应用价值。如果要将性别比操纵技术作为提高产量的一种手段，则有必要彻底了解性别比的演变。操纵种群性别比可以通过增加后代的数量来极大地提高产量。

R.A. Fisher first proposed that there is a mechanism of selection for the evolution of a sex ratio of 1/2 males and 1/2 females in populations in which there is equal investment in males of females. Although the principles suggested by Fisher are widely accepted, no one has provided test results supporting them. Experimental testing of this theory is important to basic scientific research, but it requires an animal system with genetic variation in sex ratio. Variation of this type is found in the platyfish, Xiphophorus maculatus, a tropical freshwater fish which has three sex chromosomes (W,X,Y). This experiment will investigate sex ratio changes from one generation to the next in populations of platyfish which are initiated with sex ratios other than 1/2. The results will be compared to those predicted by computer simulations. This project will provide quantifiable results supporting a generally accepted theory of sex ratio evolution. This research is important not only to basic science, but also has potential applications to aquaculture. A thorough understanding of sex ratio evolution is necessary if sex ratio manipulation techniques are to be applied as a means to increase production. Manipulation of population sex ratios could greatly increase production by increasing the number of offspring produced in the following generation.