Ecological genetics of a mosaic hybrid zone: mitochondrial, nuclear, and reproductive differentiation of crickets by soil type

Abstract

Presumptive pure Gryllus pennsylvanicus were sampled from fields in NW Connecticut and represent "inland' populations. "Pure' Gryllus firmus were sampled from beaches along the coast and represent the "coastal' populations. Crickets from within the hybrid zone were sampled from loamy sandy soils. In general, there was little variation in morphological traits or in allozyme and mtDNA genotype frequencies among localities from within each of the four habitat types. Between each of the closely situated sand and loam localities within the hybrid zone, however, there were very significant differences in each of these sets of markers. This hybrid zone is a mosaic of strikingly differentiated populations. -from Authors