Machine learning reveals how often fish schooling evolved—and repeatedly disappeared

Scientists have used new machine learning techniques to investigate a topic no one has ever found a way to study: the evolution of fish moving together in schools across thousands of species. The new paper, published Nov. 6 in the Proceedings of the National Academy of Sciences, is among the largest studies of the evolution of any behavior ever conducted in any group of species, according to the authors. The research shows that behaviors, which have previously been difficult to quantify, can be studied at a large evolutionary scale.