You’re unemployed, your landlord constantly complains about you being late with rent, or your parents want to kick you out of the basement, you would rather eat junk food than cook for yourself, or you spend most of your days playing video games or watching movies and shows on Netflix. You no longer need to make excuses and worry about those who complain about your lifestyle. A new collection of data from a study suggests that evolution favors the survival of the laziest.
Scientists from The University of Kansas looked at the data of fossils and extant bivalves and gastropods in the Atlantic ocean. The data surprisingly reveals that many species used laziness for the best excuse and strategy to survive the cruel conditions of the world. The researchers published their findings in the Proceedings of the Royal Society B.
Lower metabolic rate
Researchers went back to a period of roughly 5 million years from the mid-Pliocene to today to learn about the survival of the laziest strategy. They looked at the metabolic rates of 299 different species. They discovered that organisms with higher metabolic rates were predicted to more likely be extinct.
“We wondered, ‘Could you look at the probability of extinction of a species based on energy uptake by an organism?'” Luke Strotz, postdoctoral researcher at KU’s Biodiversity Institute and Natural History Museum and lead author of the paper said in a statement. “We found a difference for mollusk species that have gone extinct over the past 5 million years and ones that are still around today. Those that have gone extinct tend to have higher metabolic rates than those that are still living. Those that have lower energy maintenance requirements seem more likely to survive than those organisms with higher metabolic rates.”
“Maybe in the long term the best evolutionary strategy for animals is to be lassitudinous and sluggish—the lower the metabolic rate, the more likely the species you belong to will survive,” Bruce Lieberman, professor of ecology and evolutionary biology, said. “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.'”
Crucial for predicting likelihood of extinction
According to the researchers, the survival of the laziest strategy may help them determine and forecast which species could go extinct in the future, and in that way they would be able to prevent it before those species become critically endangered. The research is especially handy now, when we are facing climate change, and things can go pretty unpredictable from here.
“In a sense, we’re looking at a potential predictor of extinction probability,” Strotz said. “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. 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.”
Another discovery by the team is that species with higher metabolic rates could help indicate a higher extinction probability, and that those species usually lived in a smaller habitat. This also means they were more likely not to go extinct if they were spread out over a larger area of the ocean.
“We find the broadly distributed species don’t show the same relationship between extinction and metabolic rate as species with a narrow distribution,” Strotz said. “Range size is an important component of extinction likelihood, and narrowly distributed species seem far more likely to go extinct. If you’re narrowly distributed and have a high metabolic rate, your probability of extinction is very high at that point.”
Also the team looking at the survival of the laziest strategy discovered that cumulative metabolic rates found in communities of species were stable, adding that individual species were disappearing from the community.
The researchers explain that the metabolic rate on average remains unchanged for all the species that make up a community.
“There seems to be stasis in communities at the energetic level. In terms of energy uptake, new species develop – or the abundance of those still around increases – to take up the slack, as other species go extinct.”
According to Strotz, the team used mollusks to study the phenomenon of survival of the laziest, and it contribution to how some species go extinct. Mollusks were used because of the vast amount of data that they could use, living and extinct.
“You need very large data sets with a lot of species and occurrences,” he said. “Many of these bivalves and gastropod species are still alive, so a lot of the data we needed to do this work can come from what we know about living bivalve and gastropod physiology.”
The research won’t stop here, they will continue studying the impact of metabolic rate on extinction rates of other kinds of animals, not just those in the ocean.