The Complexity Ratchet: Stronger than selection, weaker than robustness

Vincent Liard 1, 2 David Parsons 2, 3 Jonathan Rouzaud-Cornabas 2 Guillaume Beslon 2, 1
2 BEAGLE - Artificial Evolution and Computational Biology
LIRIS - Laboratoire d'InfoRmatique en Image et Systèmes d'information, Inria Grenoble - Rhône-Alpes, LBBE - Laboratoire de Biométrie et Biologie Evolutive - UMR 5558
Abstract : Using the in silico experimental evolution platform Aevol, we evolved populations of digital organisms in conditions where a simple functional structure is best. Strikingly, we observed that in a large fraction of the simulations, organisms evolved a complex functional structure and that their complexity increased during evolution despite being a lot less fit than simple organisms in other populations. However, when submitted to a harsh mutational pressure, we observed that a significant proportion of complex individuals ended up with a simple functional structure. Our results suggest the existence of a complexity ratchet that is powered by epistasis and that cannot be beaten by selection. They also show that this ratchet can be overthrown by robustness because of the strong constraints it imposes on the coding capacity of the genome.
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Submitted on : Thursday, September 27, 2018 - 11:19:45 AM
Last modification on : Wednesday, April 3, 2019 - 1:10:45 AM
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Vincent Liard, David Parsons, Jonathan Rouzaud-Cornabas, Guillaume Beslon. The Complexity Ratchet: Stronger than selection, weaker than robustness. ALIFE 2018 - the 2018 conference on artificial Life, Jul 2018, Tokyo, Japan. pp.1-8, ⟨10.1162/isal_a_00051⟩. ⟨hal-01882628⟩



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