They Shouldn't Have Don't It
The Daily Galaxy • • science
Key Points:
- Researchers at the University of Yamanashi conducted a 20-year serial cloning experiment with mice, repeatedly cloning from a single female donor to test whether mammal cloning could sustain itself over many generations.
- The cloned mice appeared healthy for the first 25 generations, but birth rates declined starting at generation 27, and the final 58th generation died shortly after birth, showing a clear limit to serial cloning viability.
- Genome sequencing revealed a gradual accumulation of mutations over generations, with cloned mice accumulating DNA damage at a rate three times higher than naturally bred offspring, undermining genetic stability.
- Fertility declined significantly in later generations, with litter sizes dropping sharply by generations 50 and 55, although offspring produced through sexual reproduction from late-generation clones showed partial recovery.
- The study demonstrates that while cloning can produce multiple generations, accumulated genetic damage inevitably limits long-term viability, highlighting the importance of genetic reshuffling in maintaining healthy populations.
