Why Sex? and Why Only in Pairs?
探讨有性繁殖的目的，通过分析为何不存在三亲物种，区分了两种主流理论（红皇后和突变理论），发现只有一种理论能解释双亲有性相对于无性及三亲的优势。
Understanding the purpose of sex is a fundamental unresolved problem in evolutionary biology. The difficulty is not that there are too few theories of sex, the difficulty is that there are too many and none stand out. To distinguish between theories, we ask: Why are there no triparental species with offspring composed of the genetic material of three individuals? A successful theory should confer an advantage to biparental sex over asexual reproduction without conferring an even greater advantage to triparental sex. Of two leading theories (red queen and mutational) we show that only one is successful in this sense. \n \n