Researchers working in Iceland said on Sunday they identified a genetic pattern that makes some Europeans more fertile. The genetic pattern, known as an inversion, is a stretch of the DNA code that runs backwards in people who carry it. Usually, such rearrangements of a chromosome are harmful to carriers. But this one causes carriers to have more children each generation -- giving them what is known as a selective advantage, the researchers reported. The finding, published in Monday’s issue of the journal Nature Genetics, opens some interesting questions about human evolution, the team at Iceland’s DeCODE Genetics said.