Aging is no fun but if it’s any consolation, we’re not the only creatures who experience age-related declines. Insects get old too, even if they only live a few weeks, a new study finds.
“Just like humans, crickets get old,” said Dr. Rolando Rodríguez-Muñoz, of the Centre for Ecology and Conservation on the University of Exeter’s Penryn Campus in Cornwall, UK. “Though we didn’t find evidence of ‘live fast, die young’ in this species, those that put more energy into reproduction early in life showed some signs of faster decline as they aged.”
How do you know a cricket is old? Well, among other things, they chirp less and lose more fights.
Rodríguez-Muñoz and his team know this because they used more than 130 video cameras to study every hour of the lives of a colony of wild crickets in a Spanish meadow. Over a ten-year period, they monitored reproductive effort, aging and survival of thousands of cricket generations.
Their conclusion: crickets living the wild, as opposed to in laboratories, experience the same age-related declines as other species.
They found no evidence of a “trade-off” between reproductive effort in early life (measured by emergence date, calling, searching and winning fights) and survival. But the crickets that invested more in reproduction did show signs of “aging.”
“There’s a big question in biology about why we fall apart as we get old,” said Professor Tom Tregenza, also of the University of Exeter, in a news release.
“In the past, it was thought that there was something inevitable about declining with age. But there has been a shift towards believing this is something we have evolved to do,” Tregenza said. “Aging may not be about inevitable decline, but about passing our genes on. In other words, we age because — instead of using our energy to maintain ourselves — we put it into reproduction.
“Selection might favor reproduction — passing on lots of copies of your genes — over simply surviving.”