New study by Hadjivasiliou lab in Physical Review Letters

How new traits can emerge in evolution has puzzled biologists since Darwin, partly because selection can act only on already existing features. In particular, our understanding of how several new attributes necessary for complex biological mechanisms jointly emerge during evolution is limited. Furthermore, the role of physics in determining fitness and the trajectory of evolution has been largely missed in theoretical models of evolution.

In this work, we tackle these challenges by investigating how natural selection can lead to the evolution of ‘molecular motors’: groups of molecules which that can generate motion in one direction. Our simulations show that the selection for an average size in a collection of molecular assembly, a string of molecules, leads to treadmilling, where growth at one end is exactly compensated by shrinkage at the opposite end. Our findings show that physical constraints imposed on molecular self-assembly determines evolutionary dynamics and can lead to the emergence of complex functions.