Gene duplications in early metazoan evolution

Semin Cell Dev Biol. 1999 Oct;10(5):523-30. doi: 10.1006/scdb.1999.0333.


Major increases in complexity during animal evolution occurred at the transition from a unicellular protozoan to a multicellular metazoan, the evolution of Bilateria from diploblasts (possibly the Cambrian explosion) and during early vertebrate evolution. A role for gene duplication in the third event has been widely discussed. Here I examine the possible role of gene duplications and domain shuffling in the first two events. There is evidence for a wave of gene duplications and shuffling which may have paved the way for multicellularity; there are also examples of gene duplications that may have facilitated the transition from diploblasts to Bilateria.

Publication types

  • Review

MeSH terms

  • Animals
  • Chordata, Nonvertebrate / genetics
  • Collagen / genetics
  • Evolution, Molecular*
  • Gene Duplication*
  • Genome
  • Homeodomain Proteins / genetics
  • Phylogeny
  • Receptors, Cytoplasmic and Nuclear / genetics


  • Homeodomain Proteins
  • Receptors, Cytoplasmic and Nuclear
  • Collagen