PDF(Pubmed)
Abstract：
Reproductive isolation can result from adaptive processes (e.g., ecological speciation and mutation-order speciation) or stochastic processes such as \"system drift\" model. Ecological speciation predicts barriers to gene flow between populations from different environments, but not among replicate populations from the same environment. In contrast, reproductive isolation among populations independently adapted to the same/similar environment can arise from both mutation-order speciation or system drift.
In experimentally evolved populations adapting to a hot environment for over 100 generations, we find evidence for pre- and postmating reproductive isolation. On one hand, an altered lipid metabolism and cuticular hydrocarbon composition pointed to possible premating barriers between the ancestral and replicate evolved populations. On the other hand, the pronounced gene expression differences in male reproductive genes may underlie the postmating isolation among replicate evolved populations adapting to the same environment with the same standing genetic variation.
Our study confirms that replicated evolution experiments provide valuable insights into the mechanisms of speciation. The rapid emergence of the premating reproductive isolation during temperature adaptation showcases incipient ecological speciation. The potential evidence of postmating reproductive isolation among replicates gave rise to two hypotheses: (1) mutation-order speciation through a common selection on early fecundity leading to an inherent inter-locus sexual conflict; (2) system drift with genetic drift along the neutral ridges.
In experimentally evolved populations adapting to a hot environment for over 100 generations, we find evidence for pre- and postmating reproductive isolation. On one hand, an altered lipid metabolism and cuticular hydrocarbon composition pointed to possible premating barriers between the ancestral and replicate evolved populations. On the other hand, the pronounced gene expression differences in male reproductive genes may underlie the postmating isolation among replicate evolved populations adapting to the same environment with the same standing genetic variation.
Our study confirms that replicated evolution experiments provide valuable insights into the mechanisms of speciation. The rapid emergence of the premating reproductive isolation during temperature adaptation showcases incipient ecological speciation. The potential evidence of postmating reproductive isolation among replicates gave rise to two hypotheses: (1) mutation-order speciation through a common selection on early fecundity leading to an inherent inter-locus sexual conflict; (2) system drift with genetic drift along the neutral ridges.
摘要：
背景：生殖隔离可以从自适应过程中产生（例如，生态物种形成和突变顺序物种形成)或随机过程，如“系统漂移”模型。生态物种形成预测了来自不同环境的种群之间基因流动的障碍，但不是来自同一环境的重复种群。相比之下,独立适应相同/相似环境的种群之间的生殖隔离可能源于突变顺序物种形成或系统漂移。
结果：在适应高温环境的实验进化种群中，超过100代，我们发现了生殖隔离前后的证据。一方面,脂质代谢和角质层烃组成的改变指出了祖先和复制进化种群之间可能的预交配障碍。另一方面,男性生殖基因中明显的基因表达差异可能是适应相同环境且具有相同遗传变异的复制进化种群之间的后分离的基础。
结论：我们的研究证实，重复进化实验为物种形成机制提供了有价值的见解。温度适应过程中繁殖隔离的迅速出现表明了初期的生态物种形成。在重复之间进行繁殖后分离的潜在证据引起了两个假设：（1）通过对早期繁殖力的共同选择来进行突变顺序物种形成，从而导致固有的基因座间性冲突；（2）系统漂移，沿着中性脊进行遗传漂移。
结果：在适应高温环境的实验进化种群中，超过100代，我们发现了生殖隔离前后的证据。一方面,脂质代谢和角质层烃组成的改变指出了祖先和复制进化种群之间可能的预交配障碍。另一方面,男性生殖基因中明显的基因表达差异可能是适应相同环境且具有相同遗传变异的复制进化种群之间的后分离的基础。
结论：我们的研究证实，重复进化实验为物种形成机制提供了有价值的见解。温度适应过程中繁殖隔离的迅速出现表明了初期的生态物种形成。在重复之间进行繁殖后分离的潜在证据引起了两个假设：（1）通过对早期繁殖力的共同选择来进行突变顺序物种形成，从而导致固有的基因座间性冲突；（2）系统漂移，沿着中性脊进行遗传漂移。
