Bacterial DNA uptake and the evolution of sex

有性生殖对进化生物学家来说是一个严重的问题。它的主要结果是打乱基因组合，但我们不知道为什么这是有益的。将真核生物与细菌进行比较，可以戏剧性地澄清这些选择——如果细菌与性没有等价物，那么性为真核生物解决的问题一定是细菌所没有的。细菌有时确实有通过将DNA从一个细胞转移到另一个细胞来创造新的基因组合的过程，但这些过程可能还有其他更重要的功能。特别是，我的研究表明，细菌将DNA片段带入细胞作为食物，而不是作为新基因的来源。

Sexual reproduction poses a serious problem for evolutionary biologists. Its main consequence is to shuffle combinations of genes, but we do not know why this is beneficial. Comparison with bacteria can clarify the options dramatically-if bacteria have no equivalent to sex, then whatever problem sex solves for eukaryotes must be one that bacteria don't face. Bacteria do have processes that sometimes create new combinations of genes by moving DNA from one cell to another, but these processes likely have other, more important, functions. In particular, my research suggests that bacteria bring DNA fragments into their cells to use as food rather than as sources of new genes.