Limits of Serial Mammalian Cloning Revealed (nature.com)

• Failure of mouse cloning at the 58th generation
• Identification of cumulative genomic instability
• Evidence against indefinite asexual replication

"A 20-year longitudinal study attempting to clone mice through 58 consecutive generations has failed, indicating biological barriers to indefinite serial cloning. Researchers found that cumulative epigenetic errors and genomic instability render the somatic cell nuclear transfer (SCNT) process unsustainable over extended generational intervals. This research provides critical data on the limits of reproductive cloning technologies, suggesting that the erosion of cellular viability prevents the unlimited replication of complex organisms without the intervention of sexual reproduction to reset epigenetic signatures."