Historical changes in population size, such as those caused by demographic range expansions, can produce nonadaptive changes in genomic diversity through mechanisms such as gene surfing. We propose that demographic range expansion of a microbial population capable of horizontal gene exchange can result in genome surfing, a mechanism that can cause widespread increase in the pan-genome frequency of genes acquired by horizontal gene exchange. We explain that patterns of genetic diversity within Streptomyces are consistent with genome surfing, and we describe several predictions for testing this hypothesis both in Streptomyces and in other microorganisms.

人口规模的历史变化（如人口统计学范围的扩大引起的历史变化）可以通过基因冲浪等机制在基因组多样性中产生非自适应性变化。我们提出，能够进行水平基因交换的微生物种群的人口统计学范围扩展可以导致基因组冲浪，这种机制可以引起通过水平基因交换获得的基因的泛基因组频率的广泛增加。我们解释了链霉菌内的遗传多样性模式与基因组冲浪是一致的，并且我们描述了在链霉菌和其他微生物中测试这一假说的几种预测。