Speciation with gene flow and the genetics of habitat transitions

Melania E. Cristescu, Anna Constantin, Dan G. Bock, Carla E. CÚceres, Teresa J. Crease

Research output: Contribution to journalArticlepeer-review


Whether speciation can advance to completion in the face of initially high levels of gene flow is a very controversial topic in evolutionary biology. Extensive gene exchange is generally considered to homogenize populations and counteract divergence. Moreover, the role of introgressive hybridization in evolution remains largely unexplored in animals, particularly in freshwater zooplankton in which allopatric speciation is considered to be the norm. Our work investigates the genetic structure of two young ecological species: the pond species, Daphnia pulex and the lake species, Daphnia pulicaria. Phylogenetic and population genetics analyses were conducted on mitochondrial NADH dehydrogenase 5 (ND5) gene, the nuclear Lactate dehydrogenase (Ldh) gene and 21 nuclear microsatellite markers in 416 individuals from habitats with various degrees of permanence. The strong and consistent phylogenetic discordance between nuclear and mitochondrial markers suggests a complex evolutionary history of multiple independent habitat transition events that involved hybridization and introgression between lake and pond Daphnia. On the other hand, the low level of contemporary gene flow between adjacent populations indicates the presence of effective habitat isolating barriers. The Daphnia system provides strong evidence for a divergence-with-gene flow speciation model that involves multiple habitat transition events.

Original languageEnglish (US)
Pages (from-to)1411-1422
Number of pages12
JournalMolecular ecology
Issue number6
StatePublished - Mar 2012


  • Daphnia pulex
  • Daphnia pulicaria
  • adaptive divergence
  • ecological speciation
  • gene flow
  • habitat transition

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Genetics

Fingerprint Dive into the research topics of 'Speciation with gene flow and the genetics of habitat transitions'. Together they form a unique fingerprint.

Cite this