Forget 'survival of the fittest' – the laziest will inherit the Earth

Species which use the most energy in their daily lives die out quicker than less energetic animals, say evolutionary biologists

Ian SampleScience editor

Wed 22 Aug 2018 00.01 BSTLast modified on Thu 23 Aug 2018 16.03 BST

It is the perfect comeback for those who are admonished for not pulling their weight. Never mind that work is piling up, being lazy is a winning evolutionary strategy that postpones the extinction of the species.

That, at least, is one interpretation. Researchers who studied nearly 300 forms of mollusc that lived and died in the Atlantic over the past five million years found that a high metabolism predicted which species had gone the way of the dodo.

The sea snails, sea slugs, mussels and scallops which burned the most energy in their daily lives were more likely to have died out than their less energetic cousins, especially when they lived in small ocean habitats, the scientists found.

While the causes of extinction are varied and complex, the work points to a new link between the rate at which animals use energy to grow and maintain their body tissues and the length of time the species has on Earth.

“The lower the metabolic rate, the more likely the species you belong to will survive,” said Bruce Lieberman, a professor of ecology and evolutionary biology who led the research at Kansas University. “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’.”

Continued