---
res:
  bibo_abstract:
  - Epistatic interactions can frustrate and shape evolutionary change. Indeed, phenotypes
    may fail to evolve when essential mutations are only accessible through positive
    selection if they are fixed simultaneously. How environmental variability affects
    such constraints is poorly understood. Here, we studied genetic constraints in
    fixed and fluctuating environments using the Escherichia coli lac operon as a
    model system for genotype-environment interactions. We found that, in different
    fixed environments, all trajectories that were reconstructed by applying point
    mutations within the transcription factor-operator interface became trapped at
    suboptima, where no additional improvements were possible. Paradoxically, repeated
    switching between these same environments allows unconstrained adaptation by continuous
    improvements. This evolutionary mode is explained by pervasive cross-environmental
    tradeoffs that reposition the peaks in such a way that trapped genotypes can repeatedly
    climb ascending slopes and hence, escape adaptive stasis. Using a Markov approach,
    we developed a mathematical framework to quantify the landscape-crossing rates
    and show that this ratchet-like adaptive mechanism is robust in a wide spectrum
    of fluctuating environments. Overall, this study shows that genetic constraints
    can be overcome by environmental change and that crossenvironmental tradeoffs
    do not necessarily impede but also, can facilitate adaptive evolution. Because
    tradeoffs and environmental variability are ubiquitous in nature, we speculate
    this evolutionary mode to be of general relevance.@eng
  bibo_authorlist:
  - foaf_Person:
      foaf_givenName: Marjon
      foaf_name: De Vos, Marjon
      foaf_surname: De Vos
      foaf_workInfoHomepage: http://www.librecat.org/personId=3111FFAC-F248-11E8-B48F-1D18A9856A87
  - foaf_Person:
      foaf_givenName: Alexandre
      foaf_name: Dawid, Alexandre
      foaf_surname: Dawid
  - foaf_Person:
      foaf_givenName: Vanda
      foaf_name: Šunderlíková, Vanda
      foaf_surname: Šunderlíková
  - foaf_Person:
      foaf_givenName: Sander
      foaf_name: Tans, Sander
      foaf_surname: Tans
  bibo_doi: 10.1073/pnas.1510282112
  bibo_issue: '48'
  bibo_volume: 112
  dct_date: 2015^xs_gYear
  dct_identifier:
  - UT:000365988900054
  dct_language: eng
  dct_publisher: National Academy of Sciences@
  dct_title: Breaking evolutionary constraint with a tradeoff ratchet@
  fabio_hasPubmedId: '26567153'
...