"Scientists in Norway say they have conclusive genetic evidence that sparrows recently evolved a third species.The Italian sparrow, they argue, is a cross between the ubiquitous house sparrow and the Spanish sparrow.Whether it is a distinct species has been the subject of a long scientific debate.The Oslo team say in the journal Molecular Ecology that their evidence resolves the question.Many bird-watching guides already identify the Italian sparrow as a separate species.But this study, led by evolutionary biologist Glenn-Peter Saetre from the University of Oslo, is a genetic snapshot that appears to settle the debate.The researchers studied populations of Italian and Spanish sparrows that share the same habitat in the south-east of Italy.They took blood samples from the birds in order to extract DNA."By examining the genetics, we have shown conclusively that the Italian sparrow is of mixed origin - it is a hybrid of the house sparrow and the Spanish sparrow," Dr Saetre told BBC Nature."Second, and perhaps equally important - it is not reproducing with the Spanish sparrow, even though the two birds live side-by-side."If the birds had been breeding, the scientists say that they would have found genetic "intermediates" - birds with genes from both species..." |