Can resource costs of polyploidy provide an advantage to sex?

The predominance of sexual reproduction despite its costs indicates that sex provides substantial benefits, which are usually thought to derive from the direct genetic consequences of recombination and syngamy. While genetic benefits of sex are certainly important, sexual and asexual individuals, lineages, or populations may also differ in physiological and life history traits that could influence outcomes of competition between sexuals and asexuals across environmental gradients. Here, we address possible phenotypic costs of a very common correlate of asexuality, polyploidy. We suggest that polyploidy could confer resource costs related to the dietary phosphorus demands of nucleic acid production; such costs could facilitate the persistence of sex in situations where asexual taxa are of higher ploidy level and phosphorus availability limits important traits like growth and reproduction. We outline predictions regarding the distribution of diploid sexual and polyploid asexual taxa across biogeochemical gradients and provide suggestions for study systems and empirical approaches for testing elements of our hypothesis.

尽管有性生殖存在代价，但它仍占主导地位，这表明性具有重大益处，这些益处通常被认为源于重组和受精的直接遗传后果。虽然性的遗传益处当然很重要，但有性和无性个体、谱系或种群在生理和生活史特征上也可能存在差异，这些差异可能会影响有性和无性个体在环境梯度上竞争的结果。在此，我们探讨一种非常常见的无性相关现象——多倍体可能产生的表型代价。我们认为多倍体可能会产生与核酸生产所需的膳食磷需求相关的资源成本；在无性类群具有更高倍性水平且磷的可利用性限制了生长和繁殖等重要性状的情况下，这种成本可能有助于有性生殖的持续存在。我们概述了关于二倍体有性和多倍体无性类群在生物地球化学梯度上分布的预测，并为研究系统和检验我们假设要素的实证方法提供了建议。