Large global effective population sizes in Paramecium

Research output: Contribution to journalResearch articleContributedpeer-review


  • Margaret S. Snoke - , Indiana University Bloomington (Author)
  • Thomas U. Berendonk - , Leipzig University (Author)
  • Dana Barth - , Leipzig University (Author)
  • Michael Lynch - , Indiana University Bloomington (Author)


The genetic effective population size (Ne) of a species is an important parameter for understanding evolutionary dynamics because it mediates the relative effects of selection. However, because most Ne estimates for unicellular organisms are derived either from taxa with poorly understood species boundaries or from host-restricted pathogens and most unicellular species have prominent phases of clonal propagation potentially subject to strong selective sweeps, the hypothesis that Ne is elevated in single-celled organisms remains controversial. Drawing from observations on well-defined species within the genus Paramecium, we report exceptionally high levels of silent-site polymorphism, which appear to be a reflection of large Ne.


Original languageEnglish
Pages (from-to)2474-2479
Number of pages6
JournalMolecular biology and evolution
Issue number12
Publication statusPublished - Dec 2006
Externally publishedYes

External IDs

PubMed 16987953



  • Ciliates, Effective population size, Genome evolution, Mitochondrial DNA, Paramecium