Ellstrand Norman C, Antonovics Janis
Department of Botany and Plant Sciences, University of California, Riverside, CA, 92521.
Department of Botany, Duke University, Durham, NC, 27706.
Evolution. 1985 May;39(3):657-666. doi: 10.1111/j.1558-5646.1985.tb00402.x.
This study tests the hypothesis that one evolutionary advantage of sexual reproduction is that it produces genetically variable progeny with a density-dependent advantage mediated by resource partitioning or pest pressure. Our experimental approach involved planting separate plots of sexually-derived and asexually-derived tillers of the grass Anthoxanthum odoratum in density gradients at the two natural sites from which the source material was taken. The sexual progeny displayed a significant fitness advantage compared to the asexual progeny. But, in contrast to the expectations of the density-dependent selection hypothesis, the advantage of the sexually produced progeny is most marked at lower densities. Thus, the results of this experiment and our previous report (Antonovics and Ellstrand, 1984) seem to best support the frequency-dependent selection hypothesis for the advantage of sexual reproduction.
有性生殖的一个进化优势在于它能产生基因可变的后代，这些后代具有由资源分配或害虫压力介导的密度依赖优势。我们的实验方法包括在采集源材料的两个自然地点，按照密度梯度分别种植香茅有性繁殖和无性繁殖的分蘖小区。与无性后代相比，有性后代表现出显著的适合度优势。但是，与密度依赖选择假说的预期相反，有性产生的后代的优势在低密度时最为明显。因此，本实验结果以及我们之前的报告（Antonovics和Ellstrand，1984年）似乎最能支持关于有性生殖优势的频率依赖选择假说。
