Laziness might be the key to survival, a new study by a team of researchers from the University of Kansas suggests.
The study published in the Proceedings of the Royal Society B looked at nearly 300 types of mollusks that lived in the Atlantic Ocean from the mid-Pliocene to the present. The researchers found that high metabolic rates can predict the likelihood of extinction.
Survival Of The Sluggish
"We wondered, 'Could you look at the probability of extinction of a species based on energy uptake by an organism," said Luke Strotz, the lead author of the study. "We found a difference for mollusk species that have gone extinct over the past 5 million years and ones that are still around today."
The study calculated the resting metabolic rate of 299 species of mollusks — both living and extinct — and found a link between lower resting metabolic rates and longer life spans. The energy use, according to the data, was significantly different in the 179 species that are no longer on Earth compared to the gastropods and bivalves that still exist to this day.
While the causes of extinction of these organisms varied, Bruce Lieberman, co-author of the study, theorizes that the "lazy" creatures survive because they had a lot less energy and food requirements.
Using a creature's resting metabolic rate, however, can only be an accurate predictor of the species' lifespan if the organisms are confined in a smaller habitat. Results vary when the species is spread over a wide area.
"Range size is an important component of extinction likelihood, and narrowly distributed species seem far more likely to go extinct," explained Strotz. " If you're narrowly distributed and have a high metabolic rate, your probability of extinction is very high at that point."
The study titled "Metabolic Rates, Climate and Macroevolution: A Case Study with Neogene Mollusks" can help conservationists predict which species are at high risk of extinction when resources go low due to climate change.
Not Necessarily True For All Species
The researchers added that they used mollusks for the study because there is a large amount of data available about both living and extinct species. The next step is to find out whether metabolism also plays a role in the extinction of other animals.
Lieberman also warns that the study does not necessarily mean that people who sit on the couch all day watching television would inherit the Earth. He said that people who are lazy are actually the ones that consume the most resources and are causing the "biggest peril of our own species."