Fungal origins are oceanic and much older than we thought.

The mycological world was pretty much turned on its head earlier this week with the release of a new paper published in Nature . Stefan Bengtson and his team took core samples from the 900-m-thick basalt Ongeluk Formation from the Griquatown West Basin in South Africa. After close examination, the team recognized fossilized networks of what resembles fungal filaments. The confounding part is that this rock formation predates the previously accepted origin of fungi by 1.5 billion years! So, fungi may have originated 2.4 billion years ago!

2.4 billion years ago, this Ongeluk Formation was a bottom benthic region of an ancient ocean. So why would this dark, oceanic place be the origin of terrestrial fungi? Well, just recently, benthic ocean communities have been found to be teaming with networks of mycelia. Another new paper published in Fungal Ecology exclaim that these once thought barren places may be the largest fungal habitat on Earth, given that oceans make up the majority of Earth’s surface. 

The surface of early Earth was volatile and hectic, so it makes sense that fungi evolved in a stable, unchanging environment underneath ocean sediment. Nutrient poor places like these selected for the scavenging filamentous networks that fungi use so well today. Because resources are not spread out evenly, organisms that create networks can use their habitats more efficiently. Fungal networks have a wide surface area for scavenging scant resources, and the ability to transport these nutrients across vast distances to areas of new growth. Networks have evolved separately in several biological structures, from plant roots to the human brain, but never as early as 2.4 billion years.  

From a human perspective this is an unfathomable amount of time, as we only get to experience decades, centuries if we’re lucky.  To better understand the time scale of fungal origins, entertain your brain with this quip. If every second was a year, then it would still take 80 entire years to reach 2.5 billion years.

Now these hyphal formations are consistent with the scale and geometry of modern fungi, but this may just be the discovery of a newly described ancient lineage of network forming organisms very similar to mycelia forming fungi. We may never for certain know, but it’s just crazy to think that the ancestors of modern fungi living on forests floors across the globe probably originated from deep oceans 2.4 billion years ago. My mind is officially blown.