New Study Suggests Climate Change Could Reduce Lifespan Amongst Hundreds of Species
Researchers from Queen’s University Belfast and Tel Aviv University (Israel), have carried out one of the most comprehensive studies to date to better understand what affects life expectancy among all living vertebrates in the world. The study’s conclusions not only challenge a long-accepted theory about the lifespan of organisms, but also provide a new perspective on climate change – that global warming could have a huge impact on the life expectancy among ectothermic animals such as reptiles and amphibians.
Amphibians such as Frogs Could Be Exceptionally Vulnerable to the Consequences of Global Warming
Picture Credit: Queen’s University Belfast
The “rate of living” theory has long been accepted as an explanation as to why organisms age. According to this theory, the faster the metabolic rate the shorter the lifespan. Live fast and die after a relatively short period, in other words the “faster” the species lives in terms of the speed of its internal body functions and how quickly they start to reproduce, or how “slowly” in terms of these internal body functions and of lower reproductive rates, will determine the lifespan.
Research into How Organisms Age
This hypothesis helps to explain why some vertebrates such as frogs and reptiles may only live for a few months, whilst other species such as elephants, the Greenland shark and turtles can live for a very long time.
Giant Tortoises Can Live for Over a Hundred Years
Picture Credit: AFP/Getty Images
The Hotter the Environment – The Faster the “Rate of Living”
Until now the theory had not been tested at a global scale with all land vertebrates and there were limitations with the range of species the theory was tested on. The scientists from Queen’s University and Tel Aviv University analysed data from over 4,100 land vertebrate species from across the planet to test the prevailing “rate of living” theory.
They discovered that “rate of living” does not affect aging rates, rejecting the previously accepted link between lifespan and metabolism.
Writing in the academic journal “Global Ecology and Biogeography”, the researchers found that rates of aging in cold-blooded organisms (ectotherms), including amphibians and reptiles are linked to high temperatures. These findings led the scientists to put forward an alternative hypothesis: the hotter the environment is, the faster the rate of living that in turn leads to more accelerated aging and a shorter lifespan.
Commenting on the significance of this new study, co-author Dr Daniel Pincheira-Donoso, (School of Biological Sciences at Queen’s University Belfast) stated:
“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. Now we know that the life-expectancy of cold-blooded vertebrates is linked to environmental temperatures, we could expect to see their lifespans further reduced as temperatures continue to rise through global warming.”
A Pair of Common Frogs Mating (Rana temporaria)
Picture Credit: Everything Dinosaur
Amphibians the Most Threatened Class of the Animalia
According to date from the International Union for Conservation of Nature Red List (IUCN), some 30,000 species are currently threatened with extinction. This figure represents around 27% of all the species assessed. Amphibians are, on average, the most threatened Class, with 41% of species threatened. A press release from the Queen’s University Belfast states that nearly one in five of the world’s estimated 10,000 species of lizards, snakes, turtles, crocodiles and other reptiles are threatened with extinction.
PhD student, Gavin Stark, the lead author of the study (Tel Aviv University), explained:
“The link between lifespan in cold-blooded animals (amphibians and reptiles) and ambient temperatures could mean that they are especially vulnerable to the unprecedented global warming that the planet is currently experiencing. Indeed, if increasing ambient temperatures reduces longevity, it may make these species more prone to go extinct as the climate warms.”
Dr Pincheira-Donoso added:
“We need to further develop our understanding of this link between biodiversity and climate change. Only armed with knowledge will we be able to inform future policies that could prevent further damage to the ecosystem.”
The paper entitled, “No evidence for the “rate-of-living” theory across the tetrapod tree of life” is published in the journal Global Ecology and Biogeography. Manuscript ID GEB-2019-0279.R4.
Everything Dinosaur acknowledges the assistance of a media release from Queen’s University Belfast in the compilation of this article.
How does todays heat differ from Prehistoric heat?
Climate change is essentially being driven by human activity and it is taking place extremely fast in a geological timescale. It has been hotter in the past and the Earth’s atmosphere was very different but it is the speed of the change that is having dire consequences. Ecosystems can adapt if they have thousands of years, whereas adapting to sudden and rapid change over a few decades puts such ecosystems under extreme pressure. Over the last 66 million years (since the end Cretaceous extinction event), average global temperatures have been much higher than they are today. Ice at the poles for example is a relatively recent phenomenon, but it is the speed of the climate change and the consequences associated with pollution, monoagriculture, deforestation and loss of habitat that will compound this crisis. We are already in a 6th mass extinction event.
Before coral beds existed, when the oceans where warmer: what plants and animals populated the global oceans?
Are genetic ancestors of those types around today?
Why aren’t they replacing the bleached coral?
Using the bleached remains as a fertilized zone to expand?
When coral bleached before ocean warming, something had to feed on the remains?
Modern corals evolved in the Triassic, prior to that there were different types of corals, rugose and tabulate for example, these became extinct during the end Permian extinction event if my memory serves me correctly. Corals bleach when they expel the symbiotic algae (zooxanthellae), without the algae the coral polyps die, just leaving their mineral shells that have no real nutrient value. Bleaching of corals has taken place in the past, but it is the scale and speed of the loss of coral reefs that is having an adverse affect of marine ecosystems. Mass extinctions of marine fauna including reef ecosystems have happened in the past. There have been 5 major extinction events up until now, marine life has been devasted before, for example it has been estimated that after the end Permian extinction event it took many millions of years for marine ecosystems to recover. Any such devastation to food webs is very bad news for any species that is at the top of the food chain – such as our own species.