The first cloning experiments in the 1950s involved frogs and toads. It was not until 1997 that scientists successfully cloned the first mammal, the now world-famous sheep known as Dolly. Cloning techniques have continued to improve since then, and today there are cloned mice, salmon, and cattle.
克隆實驗開始于20世紀50年代，對象為青蛙和蟾蜍。直到1997年，科學家才成功地克隆了哺乳類動物，即世界聞名的“多莉羊”?？寺〖夹g從那時起得到了持續(xù)的進展，今天已有了克隆老鼠、克隆鮭魚和克隆牛。
克隆實驗開始于20世紀50年代，對象為青蛙和蟾蜍。直到1997年，科學家才成功地克隆了哺乳類動物，即世界聞名的“多莉羊”?？寺〖夹g從那時起得到了持續(xù)的進展，今天已有了克隆老鼠、克隆鮭魚和克隆牛。