3473 warbler220 Fill Up Your Backayrd Bird Feeder, Create a New Species For one species to diverge into two, you typically need physical separation so that two populations can breed independnetly and evolve in different ways. ... Thus, Schaefer asys, the two groups ahve begun to split genetically, and the results can alerady be seen in the birds anatoym. The southern migarnts have pointed wings that give them seped over long flights, an their wide beaks are suited for ...