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Birds’ genes can explain how new species emerge

7 September 2010

A collared flycatcher and a pied flycatcher. Now researchers are finding out what processes lie behind the differences between them.

How does a new species arise? Mapping the genes of flycatchers may reveal the answer.

A million years ago, there was probably only one flycatcher in our part of the world, the pied flycatcher. But evolution continued and the flycatcher has evolved in two directions. Now there is the collared flycatcher, which, in northern Europe, is only found on the Baltic islands of Öland and Gotland, and the pied flycatcher, which inhabits most gardens in Sweden. In terms of appearance, the only difference is the collar, but their songs and inner anatomy are also different.

“What’s more, there must be differences in their reproduction systems, since it is difficult for the two species to produce a fertile offspring,” says Hans Ellegren, a professor at the Center for Evolutionary Biology and director of the project that is mapping the genomes of the two flycatcher species.

The project is cross-disciplinary, bringing together ecology, evolution, and genomics. It is also one of the first in the world to study the entire DNA code of a wild animal.

“We want to identify the differences in the structure of the DNA codes. Then we will be able to understand what genes makes the two species separate,” explains Hans Ellegren.

With this mapping, Hans Ellegren and his colleagues are hoping to find answers to the question of how new species emerge – how long the time perspective is, and what processes and environments are involved. The researchers have already seen indications that sex chromosomes play a particularly important role in keeping the species distinct.

“This is vital knowledge if we are to be able to shoulder our responsibility of understanding and preserving biological diversity,” says Hans Ellegren.

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