"Matière et Systèmes Complexes"
2 avril 2007 à 11h30
Bâtiment Condorcet, 4ème
étage, salle 454 A.
(Hôpital Necker, Paris)
Lessons from the evolution of artificial genomes
In this talk, I will discuss the evolution of gene number
and the evolution of the amount of non-coding DNA in the artificial
organisms of the "aevol" platform. These organisms were designed with
three organisation levels (genome, proteome, phenotype) and are
local mutations as well as large rearrangements of the genomic
structure. Experiments with various per-locus mutation rates show that
the genome size always stabilises, although the fitness computation
does not penalise genome length. Both the gene number and the amount
of non-coding DNA are closely dependent on the mutational pressure,
resulting in a constant genome-wide variability level. Thus the
evolution of genome structure reflects a balance between several
conflicting pressures: (i) evolving more and more complex functions
with more and more genes, (ii) preserving the mutational robustness by
keeping the genome small and (iii) preserving genome evolvability by
keeping some non-coding DNA.