So bacteria enjoy the benefits of sex (fluid chromosomes) along with the speed and simplicity of cloning. But they don’t fuse whole cells together, and they don’t have two sexes, and so they avoid many of the disadvantages of sex. They would seem to have the best of both worlds. So why did sex arise from lateral gene transfer in the earliest eukaryotes? Work from the mathematical population geneticists Sally Otto and Nick Barton points to an unholy trinity of factors that conspicuously relates to circumstances at the origin of eukaryotes: the benefits of sex are greatest when the mutation rate
...more
