Low levels of straying are crucial, since the process provides a source of novel genes and a mechanism by which a location can be repopulated should the fish there disappear。
较低程度上鱼的离群至关重要，因为这个过程提供了新的基因来源和一种机制，通过这种机制，那些鱼群消失的地方能够得以重新繁荣起来。从意思上来讲（语法上略有区别），should=if，不过在这里多少有点even得味道。
问这句话的XDJM还真不少！ | 
