Priors and Posteriors in Bayesian Timing of Divergence Analyses: The Age of Butterflies Revisited

Research output: Contribution to journalArticle


The need for robust estimates of times of divergence is essential for downstream analyses, yet assessing this robustness is still rare. We generated a time-calibrated genus-level phylogeny of butterflies (Papilionoidea), including 994 taxa, up to 10 gene fragments and an unprecedented set of 12 fossils and 10 host-plant node calibration points. We compared marginal priors and posterior distributions to assess the relative importance of the former on the latter. This approach revealed a strong influence of the set of priors on the root age but for most calibrated nodes posterior distributions shifted from the marginal prior, indicating significant information in the molecular data set. Using a very conservative approach we estimated an origin of butterflies at 107.6 Ma, approximately equivalent to the latest Early Cretaceous, with a credibility interval ranging from 89.5 Ma (mid Late Cretaceous) to 129.5 Ma (mid Early Cretaceous). In addition, we tested the effects of changing fossil calibration priors, tree prior, different sets of calibrations and different sampling fractions but our estimate remained robust to these alternative assumptions. With 994 genera, this tree provides a comprehensive source of secondary calibrations for studies on butterflies.


  • Nicolas Chazot
  • Niklas Wahlberg
  • André Victor Lucci Freitas
  • Charles Mitter
  • Conrad Labandeira
  • Jae Cheon Sohn
  • Ranjit Kumar Sahoo
  • Noemy Seraphim
  • Rienk De Jong
  • Maria Heikkilä
External organisations
  • University of Gothenburg
  • University of Campinas
  • Smithsonian Institution
  • Capital Normal University
  • Indian Institute of Science Education and Research, Thiruvananthapuram
  • Finnish Museum of Natural History
  • University of Maryland
  • Gongju National University of Education
  • Instituto Federal de Educação, Ciência e Tecnologia de São Paulo
  • Naturalis Biodiversity Center
  • University of Helsinki
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Biological Systematics


  • Butterflies, Early Cretaceous, fossils, host plants, marginal prior, Papilionoidea, time-calibration
Original languageEnglish
Pages (from-to)797-813
Number of pages17
JournalSystematic Biology
Issue number5
Publication statusPublished - 2019
Publication categoryResearch