The Genetic Basis of Male Alternative Reproductive Strategies in a Marine Isopod: Organization, Expression andFrequency-Dependent Selection.

几乎每个物种的每一个特征都有一定程度的变异，这种变异的部分原因是遗传。众所周知，定向选择和遗传漂移的力量都能减少变异，因此它的维持很难解释，这一直是一个长期存在的问题。小型海洋甲壳动物Paracercus culta有三种不同的基于基因的男性身体形态，这影响了它们吸引和交配雌性的能力。这项拟议的研究将利用这一系统首先确定确切的遗传模式，然后描述环境如何影响负责不同形式的基因类型的表达，最后试图解释允许三种形态共存的进化力量。这个系统非常适合于解决这些重要的问题，因为基因类型和环境很容易操纵，而且生物体的世代时间很短，所以可以快速完成实验。此外，对于解释自然界中无处不在的变化，答案应该具有广泛的普遍性。

There is some amount of variation in almost every trait in every species that exists, and part of the cause of this variation is genetic. The well known forces of directional selection and genetic drift both act to reduce variation, so its maintenance is difficult to explain, and has been a long standing problem. The small marine crustacean, Paracercus sculpta has three different genetically based male body forms, which affect their ability to attract and mate with females. The proposed research will capitalize on this system to first identify the precise mode of inheritance, then describe how the environment influences the expression of the genotypes responsible for the different forms, and lastly attempt to account for the evolutionary forces that allow the three morphs to coexist. This system is uniquely suited to address these important questions, because the genotypes and the environments are easily manipulated, and the organism has a short generation time so that experiments can be done quickly. Furthermore, the answers should have broad generality for explaining the ubiquitous variation in nature.//