日本与法国科学家的研究揭示了哺乳动物种群内部惊人的亲缘关系。马和海豚，究竟孰为母牛的嫡亲堂兄？毫无疑问是属于鲸类动物的海豚，一个日本研究小组如此回答。这些日本研究人员证实鲸同海豚与偶蹄目动物（包括反刍类、河马、骆驼和猪在内的有蹄类动物）共有一个祖先。... Studies by Japanese and French scientists have revealed striking relationships within the mammalian population. Horses and dolphins, what cows coffin cousin? There is no doubt that dolphins belonging to cetaceans, a Japanese team so answer. The Japanese researchers confirmed that whales shared an ancestor with dolphins and cloven-hoofed animals (ungulates including ruminants, hippos, camels and pigs). ...