Hybrids reveal the barriers to successful mating between species

When species manage to mix, the odds are stacked against their offspring

Italian sparrows

BLURRED LINES  Italian sparrows, formed from interbreeding between house and Spanish sparrows, are a hybrid success story. Scientists are studying genetic changes that helped the Italian sparrows adapt to their environment and remain independent from their parent species.

Nicolle Rager Fuller

It’s a tale as old as wine.