What drove the evolution of the earliest animal life? In modern animals, it’s easy to infer a lot about an organism’s lifestyle based on its anatomy. Even back in the Cambrian, with its large collection of bizarre looking creatures, these inferences are possible. Anomalocaris may have had a freakish, disk-shaped mouth, but it clearly was a mouth.

Go back to Earth’s earliest animals in the Ediacaran, however, and things get much, much harder. There’s only one species known so far that appears to have the right body plan to act as a predator of sorts. Beyond that, it’s all a collection of soft-looking fronds and segments that are difficult to ascribe any obvious function to. Faced with a lot of questions without obvious answers, biologists turned to an unlikely source of help: physicists and engineers who understand fluid mechanics.

All of these creatures lived in an aquatic environment, so tracing how fluid flows across them can provide some hints as to how food might have arrived. Now, the same sort of research indicates that a strange cup-shaped species grew in communities because it improved the feeding of some of the community members.