In population genetics, the fitness of an animal species sometimes declines first before evolving to a higher level of survival fitness.
Engineers know that unstable control systems paradoxically stabilize if combined in the right way.
The answer is yes. We demonstrated this in Nature Vol. This strikingly counterintuitive result is called Parrondo's Paradox. We will take a look at some simple examples and show that this effect is in fact a discrete-time manifestation of a Brownian ratchet. Future development of Parrondian strategies that can help to model cases where declining birth-death processes combine in a beneficial way are thus of great interest.