Day after day, billions of invisible fungal spores rain down upon us. Each holds the DNA blueprint for a fungus, and it can faithfully preserve that DNA for astonishing periods of time.
Last year researchers from the Japan Agency for Marine-earth Science and Technology grew a onecentimetre tall mushroom from spores recovered from a drill core, a long thin section of seabed material. Boring 2.5 km under the Pacific seabed, the bottom of the core contained 20-million-year- old sediments that carried the spores of an ancient land-based fungus. It appears most closely related to a species called Schizophyllum commune.