Cold-Blooded Animals May Hold the Key to Long Life. A Huge Study Just Tried to Find It
A new published and incredibly thorough study of ectothermic tetrapods – reptiles and amphibians – gives experts a fresh insight into the reasons why cold-blooded animals tend to have such long lifespans in relation to their size.
It's the most comprehensive study of longevity and aging ever published: 114 different scientists looking at 107 different wild populations that cover 77 different species. Decades' worth of data on animals' mode of temperature regulation, environmental temperature, distinctive characteristics and the pace of life was compiled and analyzed.
Of the 30 known vertebrate species that can survive past an age of 100 years, 26 of them are ectotherms – and so scientists were keen to find out how these animals are managing to avoid the inevitability of death for quite so long.
The study turned up multiple findings, including a link between physical or chemical traits that protect species – think hard armor, spines, shells, or a venomous bite – and slower aging. Physical traits that protected species were also linked to greater lifespan.
Technically, these are known as protective phenotypes, and they can make all the difference.
"These various protective mechanisms may reduce animals' mortality rates within generations," says evolutionary biologist Beth Reinke, from Northeastern Illinois University. "Thus, they're more likely to live longer, and that can change the selection landscape across generations for the evolution of slower aging." ...
However, the research didn't back up a different hypothesis: relying on external temperatures to regular their body temperature (as cold-blooded animals do) and the associated lower metabolism wasn't a guarantee of long life. ...
