Dolly

Dolly, the sheep, was the first mammal cloned from an adult somatic cell in 1997. While Dolly herself is not the direct subject of recent news, she serves as a crucial reference point in discussions about the limits of cloning. Recent research, primarily a 20-year study on mice conducted at the University of Yamanashi in Japan led by Teruhiko Wakayama, is exploring the long-term effects of serial cloning. This research, triggered by Dolly's successful cloning, has revealed that repeated cloning in mammals is not indefinite. After approximately 25 generations, cloned animals begin to exhibit mutations, and beyond 57 generations, cloning becomes incompatible with life. These findings highlight the limitations of cloning and underscore the importance of sexual reproduction for genetic diversity and long-term viability, making Dolly's legacy relevant in understanding the boundaries of cloning technology.