A small population is more vulnerable than a larger one, because an episode of severe weather or disease can wipe out a geographically isolated group.

 
  • 而且小族群又比大族群來(lái)得脆弱,因為極端的天候或疾病一旦發(fā)生,地理上孤立的小族群就可能整個(gè)滅絕。
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