Evans Jonathan P, Simmons Leigh W
Centre for Evolutionary Biology, School of Animal Biology M092, The University of Western Australia, Nedlands, WA, Australia.
Genetica. 2008 Sep;134(1):5-19. doi: 10.1007/s10709-007-9162-5. Epub 2007 Jul 7.
The good-sperm and sexy-sperm (GS-SS) hypotheses predict that female multiple mating (polyandry) can fuel sexual selection for heritable male traits that promote success in sperm competition. A major prediction generated by these models, therefore, is that polyandry will benefit females indirectly via their sons' enhanced fertilization success. Furthermore, like classic 'good genes' and 'sexy son' models for the evolution of female preferences, GS-SS processes predict a genetic correlation between genes for female mating frequency (analogous to the female preference) and those for traits influencing fertilization success (the sexually selected traits). We examine the premise for these predictions by exploring the genetic basis of traits thought to influence fertilization success and female mating frequency. We also highlight recent debates that stress the possible genetic constraints to evolution of traits influencing fertilization success via GS-SS processes, including sex-linked inheritance, nonadditive effects, interacting parental genotypes, and trade-offs between integrated ejaculate components. Despite these possible constraints, the available data suggest that male traits involved in sperm competition typically exhibit substantial additive genetic variance and rapid evolutionary responses to selection. Nevertheless, the limited data on the genetic variation in female mating frequency implicate strong genetic maternal effects, including X-linkage, which is inconsistent with GS-SS processes. Although the relative paucity of studies on the genetic basis of polyandry does not allow us to draw firm conclusions about the evolutionary origins of this trait, the emerging pattern of sex linkage in genes for polyandry is more consistent with an evolutionary history of antagonistic selection over mating frequency. We advocate further development of GS-SS theory to take account of the complex evolutionary dynamics imposed by sexual conflict over mating frequency.
优质精子与性感精子（GS - SS）假说预测，雌性多次交配（一妻多夫制）能够推动对可遗传雄性性状的性选择，这些性状有助于在精子竞争中取得成功。因此，这些模型产生的一个主要预测是，一妻多夫制将通过雌性儿子受精成功率的提高而间接使雌性受益。此外，与关于雌性偏好进化的经典“优质基因”和“性感儿子”模型一样，GS - SS过程预测，雌性交配频率的基因（类似于雌性偏好）与影响受精成功的性状（性选择性状）的基因之间存在遗传相关性。我们通过探究被认为影响受精成功和雌性交配频率的性状的遗传基础，来检验这些预测的前提。我们还强调了最近的一些争论，这些争论强调了通过GS - SS过程影响受精成功的性状进化可能存在的遗传限制，包括性连锁遗传、非加性效应、亲本基因型相互作用以及射精成分整合之间的权衡。尽管存在这些可能的限制，但现有数据表明，参与精子竞争的雄性性状通常表现出大量的加性遗传变异以及对选择的快速进化反应。然而，关于雌性交配频率遗传变异的有限数据表明存在强大的遗传母体效应，包括X连锁，这与GS - SS过程不一致。虽然关于一妻多夫制遗传基础的研究相对较少，使我们无法就该性状的进化起源得出确凿结论，但一妻多夫制基因中出现的性连锁模式更符合交配频率拮抗选择的进化历史。我们主张进一步发展GS - SS理论，以考虑交配频率性冲突所带来的复杂进化动态。
