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Within-host speciation of malaria parasites

  • Javier Perez-Tris
  • Olof Hellgren
  • Asta Križanauskienė
  • Jonas Waldenström
  • Jean Secondi
  • Camille Bonneaud
  • Jan Fjeldså
  • Dennis Hasselquist
  • Staffan Bensch
Publishing year: 2007
Language: English
Pages: 235-235
Publication/Series: PLoS ONE
Volume: 2
Issue: 2
Document type: Journal article
Publisher: Public Library of Science

Abstract english


Sympatric speciation—the divergence of populations into new species in absence of geographic barriers to hybridization—is the most debated mode of diversification of life forms. Parasitic organisms are prominent models for sympatric speciation, because they may colonise new hosts within the same geographic area and diverge through host specialization. However, it has been argued that this mode of parasite divergence is not strict sympatric speciation, because host shifts likely cause the sudden effective isolation of parasites, particularly if these are transmitted by vectors and therefore cannot select their hosts. Strict sympatric speciation would involve parasite lineages diverging within a single host species, without any population subdivision.

Methodology/Principal Findings

Here we report a case of extraordinary divergence of sympatric, ecologically distinct, and reproductively isolated malaria parasites within a single avian host species, which apparently occurred without historical or extant subdivision of parasite or host populations.


This discovery of within-host speciation changes our current view on the diversification potential of malaria parasites, because neither geographic isolation of host populations nor colonization of new host species are any longer necessary conditions to the formation of new parasite species.


  • Biological Sciences


  • Malaria in birds
  • Molecular Ecology and Evolution Lab
Dennis Hasselquist
E-mail: dennis [dot] hasselquist [at] biol [dot] lu [dot] se



+46 46 222 37 08



Research group


Doctoral students and postdocs

Research fellows


PhD Students, main supervisor

PhD Students, assistant supervisor


Interview about my research in the Swedish podcast "Forskarn & jag"