How a hybrid sparrow was born

Italian sparrows share traits with Spanish and house sparrows (Ellerslie77 / iStock)

By mapping the genes of a hybrid sparrow, scientists are starting to understand one way new species can be created.

What they did: The Italian sparrow, which was shown to be its own species in 2011, is the result of crosses between Spanish and house sparrows. In a paper published Wednesday in the journal Science Advances, researchers sequenced the genes of Italian sparrows, and compared them to house and Spanish sparrows. The researchers believe that hybridization could be a key driver of speciation and biodiversity.

Why this matters: Speciation occurs when individuals from two groups no longer breed. This can happen for a number of reasons, including the environment, behavioral differences and genetic differences. Sometimes, mating between two species can create a new, third animal that doesn't interbreed with either parent species. It's unclear how common this is.