In a study of island lizards exposed to a new predator, the scientists found that natural selection dramatically changed direction over a very short time, within a single generation, favoring first longer and then shorter hind legs.
In a study of island lizards exposed to a new predator, the scientists found that natural selection dramatically changed direction over a very short time, within a single generation, favoring first longer and then shorter hind legs.
一种岛屿蜥蜴出现了新的掠食者，科学家经过研究发现，一段短短的时间——仅仅一代，自然选择戏剧般有方向性地出现，使其由长肢改变到短肢。