New generations of wild ash trees are rapidly evolving resistance to the fungus devastating their numbers, scientists have discovered.

The discovery gives hope, the researchers said, and shows that allowing the natural regeneration of woodlands is vital to enabling this evolution to take place. However, it remains too early to say if the development of resistance in the ash trees can outpace the destruction being caused by the ash dieback fungus.

The genetic analysis is also a scientific breakthrough. It is the first convincing proof of a prediction made by Charles Darwin that significant changes in organisms can result from natural selection driving very many small changes, not just from one or two obvious ones.