Skip to main content
Reticulate Evolution and Marine Organisms: The Final Frontier?
International Journal of Molecular Sciences
  • Michael L. Arnold, University of Georgia - Athens
  • Nicole D. Fogarty, Florida State University
Document Type
Publication Date
  • Introgression,
  • Horizontal transfer,
  • Web of life,
  • Marine
The role that reticulate evolution (i.e., via lateral transfer, viral recombination and/or introgressive hybridization) has played in the origin and adaptation of individual taxa and even entire clades continues to be tested for all domains of life. Though falsified for some groups, the hypothesis of divergence in the face of gene flow is becoming accepted as a major facilitator of evolutionary change for many microorganisms, plants and animals. Yet, the effect of reticulate evolutionary change in certain assemblages has been doubted, either due to an actual dearth of genetic exchange among the lineages belonging to these clades or because of a lack of appropriate data to test alternative hypotheses. Marine organisms represent such an assemblage. In the past half-century, some evolutionary biologists interested in the origin and trajectory of marine organisms, particularly animals, have posited that horizontal transfer, introgression and hybrid speciation have been rare. In this review, we provide examples of such genetic exchange that have come to light largely as a result of analyses of molecular markers. Comparisons among these markers and between these loci and morphological characters have provided numerous examples of marine microorganisms, plants and animals that possess the signature of mosaic genomes.

©2009 by the authors

Additional Comments
NSF grant #: DEB-0345123
Citation Information
Michael L. Arnold and Nicole D. Fogarty. "Reticulate Evolution and Marine Organisms: The Final Frontier?" International Journal of Molecular Sciences Vol. 10 Iss. 9 (2009) p. 3836 - 3860 ISSN: 1422-0067
Available at: