AI tool reveals climate shifts may have fueled bursts of bird evolution

Institute Associate Professor David Fouhey co-developed Skelevision, an AI tool that has now revealed how Passeriformes (perching birds) evolved in rapid bursts, often coinciding with major climate shifts.

Skelevision pairs custom hardware, a high-resolution camera positioned over a surface where bird bones are arranged, with a background grid providing a common scale, and a deep neural network that detects individual bones in the resulting photos, identifies each bone's type, and traces a precise digital outline of it.

As Fouhey has explained, this approach turns a hard 3D measurement problem into a 2D one that computer vision handles well, cutting specimen-handling time from up to 30 minutes to about 45 seconds per bird. That speed let the team scan over 15,000 museum specimens and collect more than 170,000 skeletal measurements, feeding a new statistical model called bifrost.

The analysis found rapid body-shape evolution around 35 million years ago, during intense global cooling, and slowdowns roughly 15 million years later. Skelevision earlier confirmed Allen's Rule in bird wings, tying wing-bone length to thermoregulation rather than flight alone.