The biggest sticking point for people who don’t believe in evolution is the idea that because it happens over such an immense timeline, it can’t really be tracked. It can, of course, through the fossil record and gene sequencing, but some people don’t want to hear that noise. Well, scientists from the American Institute of Physics have a more acute example, one that’s only been around for a century or so: Airplanes. Just like their living counterparts, they’ve evolved to be more efficient over time, adapting to the same principles of physics.

“We showed that larger airplanes are faster, more efficient as vehicles, and have greater range,” said Adrian Bejan, the J. A. Jones Distinguished Professor of Mechanical Engineering at Duke University. “Engine mass is proportional to body mass, a design feature that is the same in animals where the mass of the motive organs — muscle, heart and lungs — is proportional to body mass.”

He’s speaking to Constructal Law, a principle of physics that underlies the evolution of flow systems as they change in design over time, that Bejan himself discovered in 1996. It applies to any “tree-like” flow system (rivers, lightning, trees themselves, etc.) as it grows and evolves over time to achieve greater efficiency.

“Simply put,” Bejan said, “the Constructal Law states that for any finite-size flow system to persist, that is, be alive, it must evolve in such a way that it provides easier and easier access to its currents.”

Just like living flying animals, airplanes exhibit proportionality between wing span and fuselage length. As for what’s in store for future aircraft, Bejan says that all you need to do is look at what’s already out there – the next, better iteration will only be incrementally different.

Bejan hopes the idea dispels some of the mystery surrounding evolution, and that it applies to everything, not just biology.