February 23, 2023
Fun Fact: Lichens may have been the first farmers on the planet.
The simple lichen Winfrenatia from the Devonian Period (407 million years ago) was made mostly of undifferentiated fungal hyphae arranged as a mat, anchoring it to its growing surface. Scattered throughout this mat, cyanobacterial cells (photobionts) were held in place in tiny pits, like “pigs in a pen”. The fungi fed on the energy the photobionts generated when they were exposed to sunlight. A cross section of Winfrenatia is below (drawing by Falconaumanni from Wikimedia Commons). Just look at those little piggies!
On the spectrum of mutually beneficial interactions, it is difficult to separate the fungi/photobiont relationship from any other form of domestication. Some fungi even resort to rustling – only forming lichens by killing other lichen-forming fungi and stealing their photobionts before settling down as a lichen themselves.
If you’re interested in more reading, see Otherlands, by Thomas Halliday. A great read about natural history… 550,000,000 years of it… I bet he’s a fungi at parties…If I ever meet him, I’ll give him a hyph-ive.