Evolutionary genomic studies find that reproductive protein genes, those directly involved in reproductive processes, diversify more rapidly than most other gene categories. Strong postcopulatory sexual selection acting within species is the predominant hypothesis proposed to account for the observed pattern. Recently, relaxed selection due to sex-specific gene expression has also been put forward to explain the relatively rapid diversification. We contend that relaxed selection due to sex-limited gene expression is the correct null model for tests of molecular evolution of reproductive genes and argue that it may play a more significant role in the evolutionary diversification of reproductive genes than previously recognized. We advocate for a re-evaluation of adaptive explanations for the rapid diversification of reproductive genes.

进化基因组研究发现，与大多数其他基因类别相比，直接参与生殖过程的那些生殖蛋白质基因的分化更加迅速。在物种内起作用的强交配后性选择是提出用来解释观察到的模式的主要假设。最近，由于性别特异性基因表达而提出的放松选择也被提出来解释相对快速的多样化。我们认为，由于性别受限的基因表达而导致的放松选择是生殖基因分子进化测试的正确无效模型，并认为它可能在生殖基因的进化多样化中起着比以前公认的更为重要的作用。我们主张对生殖基因的快速多样化的适应性解释进行重新评估。