Olgui/evolution

Islands spark accelerated evolution

From the page: Following what's known as the "island rule," small animals evolve into outsize versions of their continental counterparts while large animals shrink. Giant tortoises and iguanas still inhabit the Galápagos and a few other remote islands today, but only fossils remain of the dwarf hippopotami, elephants, and deer that once lived on islands in Indonesia, the Mediterranean, and the Pacific Ocean. The fossil record suggests that these size changes occur rapidly after species become isolated on islands, but this long standing assumption has never been empirically examined in a systematic manner. Now, in a new study published in PLoS Biology, Virginie Millien confirms that island species undergo accelerated evolutionary changes over relatively short time frames, between decades and several thousand years.


Image: Giant tortoises at the Darwin Station on Isla Santa Cruz in the Galápagos Islands. Credit Photo: Catriona MacCallum