University of Michigan researchers have used an AI tool called Skelevision to demonstrate that birds in the group Passeriformes evolved in rapid evolutionary bursts and that these bursts frequently coincided with climate shifts throughout Earth’s history.

Evolutionary theory predicts that the evolution of organisms occurs in pulsed bursts followed by slowdowns—something researchers have seen hints of in the fossil record. Now, looking at passerines, University of Michigan researchers have identified these evolutionary bursts by examining data gleaned from skeletal measurements of contemporary bird specimens. The researchers also observed that these bursts coincided with historical climate change.

“This is really important for evolutionary theory because there’s a long history, going back 100 years, that predicts the emergence of new groups, called evolutionary radiations, is often associated with an explosive burst of diversification. Evolutionary theory predicts that adaptive radiations may account for a large portion of the diversity of life on earth,” said Jake Berv, lead author of the study and postdoctoral fellow in the U-M School for Environment and Sustainability.

“This could be because of a new ecological opportunity, or it could be because a group dispersed to a new continent, resulting in dramatic accelerations in their rate of evolution. The idea is that, over time, there’s less opportunity as evolution proceeds, and so it slows down, and that this occurs in pulses across time. That’s what theory predicts, and that seems to be what we see in the data as well.”

The findings, deduced using artificial intelligence and a large-scale statistical model, are published in Nature Ecology & Evolution, and were primarily supported by Schmidt Sciences and the David and Lucile Packard Foundation.

Study: Rates of passerine body plan evolution in time and space (DOI: 10.1038/s41559-026-03110-5)

Read the full press release on the Michigan News website.