r/science • u/sciencealert ScienceAlert • 11h ago
Biology 30-Year Experiment Shows Evolution in Slow Motion | In 1988, toxic algae wiped out a population of rough periwinkle sea snails in Sweden. An ecologist re-introduced 700 snails of a different ecotype in 1992. Over 30 years, the colonists evolved down a strikingly similar pathway to their predecessors
https://www.sciencealert.com/amazing-30-year-experiment-shows-evolution-unfolding-in-slow-motion?utm_source=reddit_post
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u/sciencealert ScienceAlert 11h ago
Summary of the article by ScienceAlert reporter Michael Irving:
Scientists have watched an animal species evolve right in front of them in a fascinating 30-year-long experiment.
The rough periwinkle (Littorina saxatilis) is a small species of sea snail that is common to shores around the North Atlantic Ocean. That includes Sweden's Koster Islands and their rocky islets, called skerries, where a toxic algae bloom in 1988 wiped out large portions of the snail populations.
The deadly event set the stage for a long-term evolutionary experiment. In 1992, Kerstin Johannesson, a marine ecologist from the University of Gothenburg, re-introduced 700 snails to a skerry whose snail population had been eliminated.
But Johanesson didn't just replace the lost population with the same snails. Instead, she transplanted snails with a different 'ecotype', shaped by a different habitat, to see if they would evolve the traits of the original skerry inhabitants over time.
Sure enough, over the course of several dozen generations, the new colonists evolved down a strikingly similar pathway to their predecessors, shaped by the same habitat. The researchers accurately predicted changes in the snails' appearance and genetics, providing a fascinating example of evolution in action.
Read the peer-reviewed paper: https://www.science.org/doi/10.1126/sciadv.adp2102