Evolution: The rise and fall of island dwarfs and giants

Islands are arenas for a range of striking evolutionary phenomena, including the island rule — the tendency for larger animals to shrink and smaller animals to enlarge. A new study of insular mammals finds such body size shifts predispose these evolutionary marvels to greater extinction risk. Islands are arenas for a range of striking evolutionary phenomena, including the island rule — the tendency for larger animals to shrink and smaller animals to enlarge. A new study of insular mammals finds such body size shifts predispose these evolutionary marvels to greater extinction risk.