New research into mitochondria provides a devastating refutation of one of the main talking points of Michael Behe and the Discovery Institute neo-creationists, as “irreducible complexity” turns out to be very reducible.

Intricate cellular components are often cited as evidence of intelligent design. They couldn’t have evolved, I.D. proponents say, because they can’t be broken down into smaller, simpler functional parts. They are irreducibly complex, so they must have been intentionally designed, as is, by an intelligent entity.

But new research comparing mitochondria, which provide energy to animal cells, with their bacterial relatives, shows that the necessary pieces for one particular cellular machine — exactly the sort of structure that’s supposed to prove intelligent design — were lying around long ago. It was simply a matter of time before they came together into a more complex entity.

The pieces “were involved in some other, different function. They were recruited and acquired a new function,” said Sebastian Poggio, a postdoctoral cell biologist at Yale University and co-author of the study published Monday in the Proceedings of the National Academy of Sciences.