Credit: Horst Mahr/Imagebroker/Corbis

Swimming lizards on one of the Galapagos Islands are evolving into new species, but they also seem to be mating with lizards from neighbouring islands — possibly helping to incorporate adaptations from other populations into their gene pool.

Sebastian Steinfartz at the Technical University of Braunschweig in Germany and his colleagues analysed the genomes of more than 500 Galapagos marine iguanas (Amblyrhynchus cristatus; pictured) from the island of San Cristóbal in the Galapagos. They found evidence of ongoing hybridization between lineages from different islands, along with speciation in the San Cristóbal population.

This simultaneous hybridization and speciation could have contributed to the evolutionary success of the marine iguana, the authors say.

Proc. R. Soc. B 282, 20150425 (2015)