在撒哈拉大沙漠中,有一种土灰色的沙鼠,每当旱季到来之时,这种沙鼠都要屯积大量的草根。一只沙鼠在旱季里需要吃掉两公斤草根,而沙鼠一般都要运回10公斤草根心里才踏实,否则便会焦躁不安,吱吱叫个不停。经过研究证明,这一现象是由于一代又一代沙鼠的遗传基因所决定的,是沙鼠出 In the Sahara desert, there is a gray-ish gerbil, and when the dry season arrives, the gerbil must accumulate a large amount of grass roots. A gerbil needs to eat two kilograms of grass roots during the dry season, and gerbils generally have to transport 10 kilograms of grass roots before they are practical, otherwise they will be restless and screaming. Studies have shown that this phenomenon is determined by the genetics of generations of gerbils.