I grew up thinking that roots brought nutrients to trees, but the more we learn about fungi the more I wonder if trees are just the mechanism of fungi farming their own nutrients out of thin air. Maybe the entire tree, both above and below the ground, is a root.
Does this mean that multicellular organisms may have evolved much sooner than we thought?
It might push back the date of multicellularity for fungi, but that's evolved many times and I'm pretty sure some filamentous prokaryotes got there first, but I don't have a reference handy.
Ah ok. I thought that it happened only once or twice on Earth, but I must have been thinking of the origin of mitochondria.