Hybrid zones-natural laboratories for evolutionary studies.

Hybrid zones are currently of interest because they offer experimental material for studies of the characters and processes involved in divergence and speciation. Parapatric subspecies and races may differ for a whole range of genes and characters, from short DNA sequences through enzymes and chromosomes to morphology and behaviour. An understanding of the origins, evolution, dynamics and fates of these hybrid zone patchworks requires information from a multitude of lines of enwuiry, including taxonomy, genetics, molecular biology, ethology, ecology, biogeography and palaeoclimatology.