Marler Catherine A, Ryan Michael J
Department of Psychology, University of Wisconsin, Madison, Wisconsin, 53706.
Department of Zoology, University of Texas, Austin, Texas, 78712.
Evolution. 1997 Aug;51(4):1244-1248. doi: 10.1111/j.1558-5646.1997.tb03971.x.
We investigated the role of maintenance and origin of female mating preferences in three species of fish. Poecilia latipinna and P. mexicana are sexual species that hybridized to form the gynogenetic clonal P. formosa, which reproduces asexually but requires sperm to initiate embryogenesis. We demonstrate that all three species display almost identical and statistically indistinguishable preferences for large males. Although processes of good genes, runaway sexual selection, and direct selection could maintain preferences in the sexual species, good genes and runaway sexual selection are unlikely to operate in the asexual species. Furthermore, we found that the most likely direct selection benefit, an increase in fecundity, can also be excluded in the gynogens. We conclude that the most parsimonious explanation for this P. formosa preference is that it was inherited from the parental species and is maintained without forces generated by good genes, runaway selection, or direct selection for increased fecundity. This preference may be maintained because of pleiotropic effects (e.g., sensory bias) or mate searching costs.
我们研究了三种鱼类中雌性交配偏好的维持及起源作用。帆鳉和墨西哥帆鳉是有性物种，它们杂交形成了雌核发育的克隆物种——美丽帆鳉，该物种进行无性繁殖，但需要精子来启动胚胎发育。我们证明，这三种物种对大型雄性都表现出几乎相同且在统计学上无显著差异的偏好。尽管优良基因、失控性选择和直接选择过程可以维持有性物种的偏好，但优良基因和失控性选择不太可能在无性物种中起作用。此外，我们发现，最有可能的直接选择益处，即繁殖力的增加，在雌核发育物种中也可以排除。我们得出结论，对美丽帆鳉这种偏好最简洁的解释是，它是从亲本物种遗传而来的，并且在没有优良基因、失控性选择或因繁殖力增加而产生的直接选择所产生的力量的情况下得以维持。这种偏好可能由于多效性效应（如感官偏好）或寻找配偶的成本而得以维持。
