Cold-blooded animals have a lifespan which is exponentially related to the temperature of their environment, a new study finds.
That means that as temperatures increase due to global warming, cold-blooded animals around the world will begin dying younger. Given that the vast majority of animals on Earth are cold-blooded, including the likes of amphibians, mollusks, crustaceans and reptiles, global warming could have unexpected, profound impacts on the world’s ecosystems.
The study looked at a wide range of cold-blooded creatures, which included over 90 different species from diverse habitats: terrestrial, freshwater, and marine environments. And they studied organisms with different average longevities. What they found was startlingly consistent. While other factors certainly play a role in local life spans, ambient temperature of the environment was by far the most dominant factor overall.
In mapping the relationship between temperature and lifespan, the study was also consistent with what the metabolic theory of ecology (MTE) predicts. According to Physorg: “The MTE is a modeling framework that has been used to explain the way in which life history, population dynamics, geographic patterns, and other ecological processes scale with an animal’s body size and temperature.” It turned out that the lifespan in 87% of the species examined in this study varied as predicted by the MTE.
Here was one of the more startling examples discovered by researchers. Pearl mussels in Spain were found to have a maximum lifespan of only 29 years, while their counterparts of the same species in Russia can live as long as 200 years. The deciding factor between the difference was latitude and temperature. The mussels in Spain lived warmer, harder and faster, but the trade off was a shorter lifespan.
Santiago Salinas, one of the study’s researchers, had this to say:
“It is interesting to consider how cold-blooded species are likely to react in the face of global warming. Because of the exponential relationship between temperature and lifespan, small changes in temperature could result in relatively large changes in lifespan. We could see changes to ecosystem structure and stability if cold-blooded species change their life histories to accommodate warmer temperatures but warm-blooded species do not.”
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