Although the phrase "ontogeny recapitulates phylogeny'' turned out to be incorrect, the search for possible relationships between development and evolution still gathers much attention. Recently, dynamical-systems analysis has proven to be relevant to both development and evolution, and it may therefore provide a link between the two. Using extensive simulations to evolve gene regulation networks that shape morphogenesis, we observed remarkable congruence between development and evolution: Both consisted of the same successive epochs to shape stripes, and good agreement was observed for the ordering as well as the topology of branching of stripes between the two. This congruence is explained by the agreement of bifurcations in dynamical-systems theory between evolution and development, where slowly varying gene-expression levels work as emergent control parameters. In terms of the gene regulation networks, this congruence is understood as the successive addition of downstream modules, either as feedforward or feedback , while the upstream feedforward network shapes the boundary condition for the downstream dynamics, based on the maternal morphogen gradient. Acquisition of a novel developmental mode was due to mutational change in the upstream network to alter the boundary condition . Our results provide a fresh perspective on evolution-development relationship, as well as on the acquisition of developmental novelty .
Search for possible relationships between phylogeny and ontogeny is one of the most important issues in the field of evolutionary developmental biology. By representing developmental dynamics of spatially located cells with gene expression dynamics with cell-to-cell interaction under external morphogen gradient, evolved are gene regulation networks under mutation and selection with the fitness to approach a prescribed spatial pattern of expressed genes. For most of thousands of numerical evolution experiments, evolution of pattern over generations and development of pattern by an evolved network exhibit remarkable congruence. Here, both the pattern dynamics consist of several epochs to form successive stripe formations between quasi-stationary regimes. In evolution, the regimes are generations needed to hit relevant mutations, while in development, they are due to the emergence of slowly varying expression that controls the pattern change. Successive pattern changes are thus generated, which are regulated by successive combinations of feedback or feedforward regulations under the upstream feedforward network that reads the morphogen gradient. By using a pattern generated by the upstream feedforward network as a boundary condition, downstream networks form later stripe patterns. These epochal changes in development and evolution are represented as same bifurcations in dynamical-systems theory, and this agreement of bifurcations lead to the evolution-development congruences. Violation of the evolution-development congruence, observed exceptionally, is shown to be originated in alteration of the boundary due to mutation at the upstream feedforward network . Our results provide a new look on developmental stages, punctuated equilibrium, developmental bottlenecks, and evolutionary acquisition of novelty in morphogenesis .
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Although the phrase "ontogeny recapitulates phylogeny'' turned out to be incorrect, the search
Search
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development and evolution still gathers much attention. Recently, dynamical-systems analysis has proven to be relevant to both development and evolution, and it may therefore provide a link between the two. Using extensive simulations to evolve gene regulation networks that shape morphogenesis, we observed remarkable congruence between development and evolution: Both consisted of the same successive epochs to shape stripes, and good agreement was observed for the ordering as well as the topology of branching of stripes between the two. This congruence is explained by
phylogeny and ontogeny is one of the most important issues in the field of evolutionary developmental biology. By representing developmental dynamics of spatially located cells with gene expression dynamics with cell-to-cell interaction under external morphogen gradient, evolved are gene regulation networks under mutation and selection with the fitness to approach a prescribed spatial pattern of expressed genes. For most of thousands of numerical evolution experiments, evolution of pattern over generations and development of pattern by an evolved network exhibit remarkable congruence. Here, both the pattern dynamics consist of several epochs to form successive stripe formations between quasi-stationary regimes. In evolution, the regimes are generations needed to hit relevant mutations, while in development, they are due to the emergence of slowly varying expression that controls the pattern change. Successive pattern changes are thus generated, which are regulated by successive combinations of feedback or feedforward regulations under
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agreement of bifurcations in dynamical-systems theory between evolution and development, where slowly varying gene-expression levels work as emergent control parameters. In terms of the gene regulation networks, this congruence is understood as the successive addition of downstream modules, either as feedforward or feedback , while the
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shapes the boundary condition for the downstream dynamics, based on the maternal morphogen gradient. Acquisition of a novel developmental mode was due to mutational change in
that reads the morphogen gradient. By using a pattern generated by the upstream feedforward network as a boundary condition, downstream networks form later stripe patterns. These epochal changes in development and evolution are represented as same bifurcations in dynamical-systems theory, and this agreement of bifurcations lead to the evolution-development congruences. Violation of
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upstream network to alter the boundary condition
evolution-development congruence, observed exceptionally, is shown to be originated in alteration of the boundary due to mutation at the upstream feedforward network
R
fresh perspective on evolution-development relationship, as well as on the acquisition of developmental novelty
new look on developmental stages, punctuated equilibrium, developmental bottlenecks, and evolutionary acquisition of novelty in morphogenesis