In biology, symmetry is typically the rule rather than the exception. Our bodies have left and right halves, starfish radiate from a central point and even trees, though not largely symmetrical, still produce symmetrical flowers. In fact, asymmetry in biology seems quite rare by comparison.

Does this mean that evolution has a preference for symmetry? In a new study, an international group of researchers, led by Iain Johnston, a professor in the Department of Mathematics at the University of Bergen in Norway, says it does.