'Survival of the laziest' is key to avoiding extinction

When your mother told you to clean your room and you said you'd do it later, it turns out you were just trying to survive.

A new study from researchers at the University of Kansas suggests that species who use more energy on a daily basis are at a greater risk of becoming extinct than those that are more sedentary.

“We wondered, 'Could you look at the probability of extinction of a species based on energy uptake by an organism?'” said Luke Strotz, postdoctoral researcher at KU’s Biodiversity Institute and Natural History Museum and the study's lead author, in a statement.


In the research, Strotz and his team compared 300 million different mollusk species, including ones that had gone extinct 5 million years ago, and noted the extinct species had a higher metabolic rate. "Those that have gone extinct tend to have higher metabolic rates than those that are still living," Strotz added. "Those that have lower energy maintenance requirements seem more likely to survive than those organisms with higher metabolic rates.”

The study was published in Proceedings of the Royal Society B.

Bruce Lieberman, a co-author of the study, added that "survival of the fittest," a phrase that emerged from Darwin's evolutionary theory, may need to be revised.

“Instead of ‘survival of the fittest,’ maybe a better metaphor for the history of life is ‘survival of the laziest’ or at least ‘survival of the sluggish,’” Lieberman said.

Strotz added that though there are a lot of factors and different inputs that matter when it comes to extinction, and metabolic rate is particularly important to pay attention to.

"At the species level, metabolic rate isn’t the be-all, end-all of extinction — there are a lot of factors at play. But these results say that the metabolic rate of an organism is a component of extinction likelihood," Strotz said in the statement. "With a higher metabolic rate, a species is more likely to go extinct. So, it’s another tool in the toolbox. This will increase our understanding of the mechanisms that drive extinction and help us to better determine the likelihood of a species going extinct.”

So far, the results only apply to mollusks (which were used because of the plethora of data about living and extinct species), but added that more work needs to be done to see if there is a link between metabolic rates and other animals.

“We see these results as generalizable to other groups, at least within the marine realm,” Strotz said. “Some of the next steps are to expand it out to other clades, to see if the result is consistent with some things we know about other groups."

Clades are organisms that have evolved from a common ancestor.

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