New Delhi: Global warming could be reducing the lifespan of cold-blooded species such as reptiles and amphibians, says a new study.
Researchers from Queen’s University Belfast and Tel Aviv University in Israel have carried out one of the most comprehensive studies to understand what affects life expectancy among all living vertebrates in the world.
The findings challenge a long-accepted theory around lifespan called the ‘rate of living’ that has till date been accepted as an explanation as to why organisms age. According to this theory, the faster the metabolic rate, the shorter is the lifespan.
This means if the speed of internal body functions is high and a species starts to reproduce sooner, they will have shorter lifespan. The theory explains why some vertebrates like frogs can only live for a few months while others such as whales and turtles live on for centuries.
While this theory is over 100 years old, it had never been tested on a global scale by taking into account all land vertebrates.
‘Hotter climate leading to shorter lifespans’
For their study, the researchers analysed data of over 4,100 land vertebrate species from across the planet. They found that the ‘rate of living’ does not affect ageing rates, rejecting the previously accepted link between metabolism and lifespan.
The study, published in journal Global Ecology and Biogeography, has found that the rate of ageing in amphibians and reptiles are linked to higher temperatures.
Based on their findings, the scientists proposed an alternative hypothesis — the hotter the environment, the faster the rate of living, which in turn leads to a more accelerated ageing and a shorter lifespan.
“Our findings can have critical implications for our understanding of factors that contribute to extinctions, especially in modern times when we are facing a worldwide decline of biodiversity, with cold-blooded animals being particularly endangered,” Daniel Pincheira-Donoso, a lecturer at Queen’s University Belfast, said in a statement.
He added, “Now we know that life-expectancy of cold-blooded vertebrates is linked to environmental temperatures…we could expect to see their lifespan further reduced as temperatures continue to rise due to global warming.”
Cold-blooded animals more vulnerable to global warming
Amphibians are among the most threatened species, according to the International Union for Conservation of Nature (IUCN) Red List of endangered species.
Nearly one in five of the world’s estimated 10,000 species of lizards, snakes, turtles, crocodiles and other reptiles are threatened with extinction.
“The link between lifespan in cold-blooded animals and ambient temperatures could mean they are especially vulnerable to the unprecedented global warming that the planet is currently experiencing,” said Gavin Stark, the study’s lead author and a PhD student at Tel Aviv University.
“If increasing ambient temperatures reduce longevity, it may make these species more prone to go extinct as the climate warms,” added Stark.
Pincheira-Donoso also said there was a need to improve our understanding of the link between biodiversity and climate crisis. “Only armed with knowledge will we be able to inform future policies that could prevent further damage to the ecosystem.”