请教阅读中一句话的意思和用法

linxi8389

Low levels of straying

are crucial, since the process

provides a source of novel

genes and a mechanism

      by which a location can be

(40)     repopulated should the fish

there disappear.         Should the fish there disappear 在这儿是怎样用法啊

linxi8389

我自己把它想明白了．应该是等于if the fish there should disappear ,表虚拟语气。

对吗，请指教

rhod

Yes.