So why are the lifespans of most rodents, mice, rats and squirrels so short? Researchers have compared genes of long- and short-lived rodents; it would appear several novel (unique) genes influence longevity and healthy aging in mammals. Most rodent’s life prospect and early death during aging are predominantly high. Interesting, small rodents like mice or rats live no longer than 9 months to three years, while mole-rats or crepuscular rodents have an average life span up to 30+ years, in relatively good health. Genes selected by evolution for a long and healthy life were under-activated in long-lived rodents, yet over-activated in short-term species. Long-lived rodents’ genes are 86% identical to human DNA. There also appears to be a strong connection between fast growth and long lifespan. The same genes that make a rodent mature fast also accelerate the aging process; that shorten its lifespan.
https://www.linkedin.com/pulse/rodents-quick-maturing-shorter-life-randy-bilesky/?published=t