weekly blog--one for the ages
There is a giant tortoise on the island of St. Helena in the South Atlantic that was born in 1832. Sea turtles can live from 50 to 100 years. Box turtles can live more than a century. So why do turtles live so long? There's an evolutionary answer and a biological answer, says a professor at Arkansas State University who studies turtles and other reptiles.
The evolutionary answer is relatively straightforward: Animals such as snakes and racoons love to eat turtle eggs. To pass on their genes, turtles have to live a long time and breed frequently, sometimes multiple times per year, and lay a lot of eggs.
The biological mechanism behind turtles' longevity is more complicated. One clue to turtles' longevity lies in their telomeres, structures composed of noncoding strands of DNA that cap the ends of chromosome. These structures help protect the chromosomes as cells divide. Over time, telomeres get shorter or degrade, which means they can no longer protect their chromosomes as well, leading to issues with DNA replication. And errors in DNA replication can lead to issues such as tumors and cell death.
Also, giant tortoises and a few other turtle species seem to be able to protect themselves from the long-term effects of cell damage. They do this by quickly killing off damaged cells, using a process called apoptosis or programmed cell death.
Learn More: Why do turtles live so long? | Live Science