Genetic diversity and divergence of endangered Galapagos and Hawaiian Petrel populations

Abstract

The genetic diversity and divergence of populations of Galapagos and Hawaiian Petrel (Pterodroma phaeopygia and sandwichensis, respectively) were investigated using allozyme electrophoresis. Within the Galapagos Islands, P. phaeopygia samples were monomorphic at 12 of 13 loci. The Hawaiian population P. sandwichensis was monomorphic at all 13 loci. One fixed allelic difference was found between P. phaeopygia and P. sandwichensis. Eleven loci were fixed for the same allele in both populations. Our results indicate that there has been no recent gene flow between Galapagos and Hawaiian Petrels, but gene flow occurs among Galapagos populations of P. phaeopygia. The existence of a unique genetic variant discriminating Galapagos and Hawaiian Petrels, in addition to previously documented morphological and behavioral differences, supports the recent elevation of these two taxa to species status.