Lively C M, Howard R S
Department of Biology, Indiana University, Bloomington 47405.
Philos Trans R Soc Lond B Biol Sci. 1994 Nov 29;346(1317):271-80; discussion 280-1. doi: 10.1098/rstb.1994.0144.
On theoretical grounds, coevolutionary interactions with parasites can select for cross-fertilization, even when there is a twofold advantage gained by reproducing through uniparental means. The suspected advantage of cross-fertilization stems from the production of genetically rare offspring, which are expected to be more likely to escape infection by coevolving enemies. In the present study, we consider the effects that parasites have on parthenogenetic mutants in obligately sexual, dioecious populations. Computer simulations show that repeated mutation to parthenogenesis can lead to the accumulation of clones with different resistance genotypes, and that a moderately diverse set of clones could competitively exclude the ancestral sexual subpopulation. The simulations also show that, when there are reasonable rates of deleterious mutation, Muller's ratchet combined with coevolutionary interactions with parasites can lead to the evolutionary stability of cross-fertilization. In addition, we consider the effects that parasites can have on the evolution of uniparental reproduction in cosexual populations. Strategy models show that parasites and inbreeding depression could interact to select for evolutionarily stable reproductive strategies that involve mixtures of selfed and outcrossed progeny.
从理论上讲，与寄生虫的协同进化相互作用可以促使生物选择异体受精，即便通过单亲生殖方式繁殖具有两倍的优势。异体受精的潜在优势源于产生基因上罕见的后代，这些后代预计更有可能逃脱共同进化的天敌的感染。在本研究中，我们考虑寄生虫对专性有性、雌雄异株种群中孤雌生殖突变体的影响。计算机模拟表明，反复突变为孤雌生殖会导致具有不同抗性基因型的克隆体积累，并且一组适度多样的克隆体能够竞争性地排除原始的有性子种群。模拟还表明，当存在合理的有害突变率时，穆勒氏棘轮效应与与寄生虫的协同进化相互作用相结合，能够导致异体受精的进化稳定性。此外，我们考虑寄生虫对两性种群中单亲生殖进化的影响。策略模型表明，寄生虫和近亲繁殖衰退可能相互作用，从而选择涉及自交和异交后代混合的进化稳定生殖策略。
