1Evolution-Development Congruence in Pattern Formation Dynamics: Bifurcations in Gene Expressions and Regulation of Networks Structures

Deciphering and understanding potential relationships between evolution and development has been an important research goal for over a century. Recent advancements in quantitative analyses based on comparative genomics and massive gene expression data suggest that the time is ripe to uncover new re-lationships on phylogeny and ontogeny. By representing the developmental dynamics of spatially located cells with gene expression dynamics involving cell-to-cell interactions, under an external morphogenic gradient, we numerically evolved gene regulation networks, subject to mutation and selection, as they approach a prescribed spatial pattern of expressed genes. From analyses of hundreds of numerical evolu-tion experiments, remarkable congruence was observed between generational change in patterns through evolution along a single chain phylogeny and that through developmental process of the evolved descen-dant. Here, both of the pattern dynamics consisted of several epochs capable of producing successive stripe formations between quasi-stationary regimes. These epochs are represented as bifurcations in dynamical-systems theory, and thus the evolution-development congruence is understood as a corre-spondence of bifurcation. A quasi-stationary regime in development is due to component(s) with slowly varying expression, while in evolution, generations are needed to produce relevant mutations. The evolve