Symmetry Breaking and the Evolution of Development

@article{Palmer2004SymmetryBA,
  title={Symmetry Breaking and the Evolution of Development},
  author={A. Richard Palmer},
  journal={Science},
  year={2004},
  volume={306},
  pages={828 - 833}
}
Because of its simplicity, the binary-switch nature of left-right asymmetry permits meaningful comparisons among many different organisms. Phylogenetic analyses of asymmetry variation, inheritance, and molecular mechanisms reveal unexpected insights into how development evolves. First, directional asymmetry, an evolutionary novelty, arose from nonheritable origins almost as often as from mutations, implying that genetic assimilation (“phenotype precedes genotype”) is a common mode of evolution… 
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References

SHOWING 1-10 OF 75 REFERENCES
The embryonic origins of left-right asymmetry.
  • M. Levin
  • Biology
    Critical reviews in oral biology and medicine : an official publication of the American Association of Oral Biologists
  • 2004
TLDR
Based on wide-ranging data on ion fluxes and motor protein function in several species, it is suggested that laterality is driven by pH/voltage gradients across the midline, which are established by chiral movement of motor proteins with respect to the cytoskeleton.
From symmetry to asymmetry: phylogenetic patterns of asymmetry variation in animals and their evolutionary significance.
  • A. R. Palmer
  • Biology
    Proceedings of the National Academy of Sciences of the United States of America
  • 1996
TLDR
The phylogenetic transition from antisymmetry to directional asymmetry suggests that many cases of laterally fixed asymmetries evolved via genetic assimilation, and the ontogenetic origin of asymmetry significantly influences its subsequent evolution.
Developmental mechanism and evolutionary origin of vertebrate left/right asymmetries
  • J. Cooke
  • Biology
    Biological reviews of the Cambridge Philosophical Society
  • 2004
TLDR
An overview, rather than an exhaustive scholarly review, is given of recent advances in molecular understanding of the mechanism that ensures normal development of correct’situs, and it now seems probable that earlier steps, in which symmetry‐breaking information is reliably transduced to trigger these cascades on the correct sides, are also conserved at depth, although it remains unclear exactly how these steps operate.
Establishment of vertebrate left–right asymmetry
The generation of morphological, such as left–right, asymmetry during development is an integral part of the establishment of a body plan. Until recently, the molecular basis of left–right asymmetry
The evolution of left–right asymmetry in chordates
TLDR
It is suggested that left–right asymmetry in all chordates is regulated by a conserved developmental pathway, and that this pathway evolved before the separation of the lineages leading to living chordates.
Analyzing evolutionary patterns in amniote embryonic development *
TLDR
Clear patterns of heterochrony are identified, which suggest that advanced heart development arose in evolutionary history before endothermy, and can be adapted to analyze other forms of comparative dynamic data, including patterns of developmental gene expression.
Developmental system drift and flexibility in evolutionary trajectories
TLDR
Current data on the population genetics and molecular mechanisms of DSD illustrate how the details of developmental processes are constantly changing within evolutionary lineages, indicating that developmental systems may possess a great deal of plasticity in their responses to natural selection.
Conservation and divergence in molecular mechanisms of axis formation.
TLDR
The postfertilization mechanisms underlying axis specification in Drosophila are examined, finding similarity between axial patterning mechanisms elucidated genetically in Dosophila and those demonstrated for chordates such as Xenopus.
...
...