This Special Topic contains one perspective and three original articles that address the topic of convergent evolution.How common,and how important,is convergent adaptation in evolution? These are the questions these studies attempt to answer.If the concept of evolution has to be encapsulated in a single word,that word must be adaptation or,in a few more words,selection for the fittest.Nevertheless,proving adaptation is extremely difficult.For example,if human intelligence is adaptive (as we suspect that it must be),why are Homo sapiens the only species sufficiently intelligent to contemplate its own adaptation? One way to show adaptation,dating back to Darwins On the Origin of Species,is convergent evolution.When multiple taxa independently evolved the same trait to cope with the same,or similar,environmental pressures,the trait is likely adaptive in that environment.