Hybridization and polyploidization are powerful mechanisms of speciation. Hybrid speciation often coincides with whole-genome duplication (WGD) in eukaryotes. This suggests that WGD allows hybrids to thrive by restoring fertility and/or increasing access to adaptive mutations. Alternatively, it has been suggested that hybridization itself may trigger WGD. Testing these models requires quantifying the rate of WGD in hybrids without the confounding effect of natural selection. By measuring the spontaneous rate of WGD of 1304 yeast crosses evolved under relaxed selection, we show that some genotypes are more prone to WGD and WGD can be triggered by hybridization. We also find that higher WGD rate correlates with higher genomic instability and that WGD increases fertility and genetic variability. These results provide evidence that hybridization itself can promote WGD, which in turn facilitates the evolution of hybrids.

中文翻译：

---

杂交可以加快全基因组复制的速度

杂交和多倍体化是物种形成的强大机制。杂交物种通常与真核生物的全基因组复制（WGD）相吻合。这表明WGD可通过恢复繁殖力和/或增加获得适应性突变的途径使杂种繁衍生息。备选地，已经提出杂交本身可以触发WGD。测试这些模型需要在没有自然选择的混淆影响的情况下量化杂交种中WGD的比率。通过测量在宽松选择下进化的1304个酵母杂交的WGD的自发率，我们显示了一些基因型更倾向于WGD，并且WGD可以通过杂交触发。我们还发现，较高的WGD比率与较高的基因组不稳定性相关，并且WGD增加了生育力和遗传变异性。