Sunday, March 11, 2018

The View from Les Houches: the Revenge of Lotka and Volterra

Les Houches, March 2018. Fatma Rostom of the University of Paris, shows the basis of her model of the energy transition. It is the good, old Lotka-Volterra model, also known as the "Predator-Prey" or the "Rabbits and Wolves" model. (the LV model, among friends)

Perhaps surprising, this model, presented first in the 1920s, is enjoying a new life today and it was mentioned in several talks. Long considered a toy for freshmen in biology, it turns out to be extremely rich in its capability of describing the stepped dissipation of thermodynamic potentials in a nonequilibrium system.

Dr. Rostom modified the model in order to take into account economic and monetary factors, but even the "raw" LV model can describe real-world phenomena. It was found to be at the basis of the Hubbert Curve (Bardi and Lavacchi, 2009) and it was recently shown to be able to describe the cycle of exploitation of fisheries (Perissi et al. 2017). And, of course, the model is at the basis of the dynamical interpretation of the "Seneca Effect"

The talk by Dr. Rostom was very good for several reasons, one for her emphasis on "mind-sized" models, a concept that I had introduced some years ago under the influence of Seymour Papert. In the current situation of confusion and even of despair, we badly need models that policymakers can understand if they have to act in a meaningful way

But, in the end, what results did Dr. Rostom reported. Well, not very optimistic ones, as you can see in this paper of hers and others


  1. To make this even more accessible artist Stuart McMillan created this little comic to illustrate predator prey relations on the example of St. Matthews island. See:

    I fear that many simply do not even try to understand.

  2. Predators run to eat. Prey run to live. So you gotta ask yourself, punk. Are you good at being prey?

  3. Her paper seems to have a broken link.

    1. It seems to work. It is a docx file. Would you try again?

    2. “Appears to be corrupted”



Ugo Bardi is a member of the Club of Rome and the author of "Extracted: how the quest for mineral resources is plundering the Planet" (Chelsea Green 2014). His most recent book is "The Seneca Effect" (Springer 2017)