Meme #9 - Symbiosis

In Entangled Life, Merlin Sheldrake takes time for an in-depth analysis of symbiosis, in particular detailing how the discovery of lichen's compound nature changed our understanding of ecology. Lichen are organisms composed of a fungus (called the mycobiont, which draws up minerals and water) and any number of algae and/or bacteria (called photobionts, which provide sugars and lipids through photosynthesis). Sheldrake states: 

In their relationship, both partners were able to make life in places neither could survive alone. (p.72) 

Within lichens, branches of the tree of life that had been diverging for hundreds of millions of years were doing something entirely unexpected: converging. (p.72) 

[Symbiosis] refers to the full spectrum of interactions between any type of organism, stretching from parasitism at one pole, to mutually beneficial relationships at the other. (p.73) 

In the wake of [this discovery], evolution could no longer be thought of solely in terms of competition and conflict. Lichen had become a type case of inter-kingdom collaboration. (p.73) 

Broadly speaking, symbiosis describes the dynamics and interplay of all life - every organism depends on other life forms to survive and thrive. Even predators like wolves, and prey animals like elk, rely on each other for individual fitness and balanced populations. This is an example of natural selection. Members of a wolf pack that are most able to feed - and stay injury free - are most likely to reproduce, thus transferring their unique fitness to their offspring. Elk that are most able to escape from predators - and stay injury free - are also most likely to reproduce, thus passing down their unique fitness. Without wolves, elk populations explode, weakening their overall fitness and degrading the environment on which they depend. In the long run this will eliminate the herd. Without elk, the wolves starve to death. Truly, both species greatly depend on each other.

Fungi are also part of this dance. An article by the Leibnitz Institute of Freshwater Ecology and Inland Fisheries, describes how a fungal parasite keeps harmful blue algae in check: 

When a lake is covered with green scums during a warm summer, cyanobacteria – often called blue-green algae – are usually involved. Mass development of such cyanobacteria is bad for water quality because they can deprive the water of oxygen and produce toxins. But cyanobacteria can become sick, when for instance infected by fungal parasites. Researchers from IGB found out that these infections do not only kill cyanobacteria, they also make them easier to consume for their natural predators. Fungal parasites thus help to slow down the growth of blue-green algae. 

But this balance can be upset by the introduction of gene variants, which is a biological process that consistently adds new traits to individual specimens. Most genetic variants fail and don’t get passed down to future generations, but a rare new trait might hit on the exact need of the moment. For instance, a variant gene in a single alga may allow it to survive a fungal attack, thus permitting the transfer of this novel ability to its descendants so they can also fight off the fungi. But fungi develop gene variants too and one might hit upon an ability to neutralize the recently developed alga variant. It’s this type of “arms race” that underlies the balance of nature. 

Mutually beneficial symbiosis provides a slight variation to this dance. In this case, both organisms cooperate to gain an advantage that neither have alone, and, neither side is vying for dominance over the other - it’s a partnership. Lichen are given as prime examples. But doubts arise about even this paradigmatic case if we examine the relationship closely because we’ll learn that only the fungal partner can reproduce sexually. The lichen itself can reproduce asexually, expanding over the surface of a rock or tree but the fungal partner can also produce spores that float off to team up with other compatible photobiontic organisms to form a new lichen. So, perhaps lichen may lean toward the “parasitism” side of the spectrum as well? In a sense, the photobiont can be seen as getting “hijacked” by the mycobiont, who is the only partner able to individually reproduce. The alga and/or bacteria survive in environments they could not otherwise, but they do not thrive according to the biological imperative of sexual reproduction. 

But common mycorrhizal networks, where fungi link various species of plants within an eco-system, take this symbiotic dance in a fundamentally different direction. From Sheldrake’s perspective, the fungi are the directors and conductors of this mutually beneficial web of life, moving resources from one plant to the other - from dying trees to healthy trees (even of different species) and from mature trees to developing trees (that are blocked from the sun and not yet able to photosynthesize). This “management” of the ecosystem maintains the overall health of the forest, thus providing the fungi a diversified and sustainable portfolio of sugars and lipids produced in photosynthesis. I believe it is this type of symbiotic relationship that we should emulate to live according to the Way of Fungi. It would allow for the active management of a system (for our own benefit) in a way that guarantees its vital health because we’d be encouraging each individual organism to thrive. And it could also leave room for the human trait of compassion to be introduced to the mix. 

Here's how. Common mycorrhizal networks are a phenomenon of the natural world and thus unconcerned about the niceties of feelings. An old tree is dying? There’s no question, take its resources and transfer them to a young tree that has an entire lifetime ahead of it. It works, but it’s heartless. It would be horrifying for us to act this way - confiscating the resources of older adults and redistributing them to the young. Therefore, the question is: how do we adopt the undeniably successful aspects of common mycorrhizal networks while also integrating the human tendency toward compassion? The answer is simple: balance pure efficiency with elements that provide depth and meaning. 

Depth and meaning are two characteristics that fungi (as far as we know) are not worried about, but which we should be. For instance, elder humans are not as productive as younger humans and therefore add less to the economic system. In fact, they take away from the system in terms of the resources needed to care for their fragile health and provide the necessary support services. But these folks are vital for passing on the wisdom of their years to the next generation - if the tots are available for them to influence. However, in our modern world elders are often shunted away far from daily interactions with these small children and therefore society is not benefitting at all from this positive effect. If we are to act compassionately, this situation would demand a reconfiguring of the system rather than the “culling” of the old and infirm. Another example relates to issues connected to overpopulation. Nature takes care of this problem through (among other things) high infant mortality rates. Governments have also introduced draconian measures that limit the number of births per family. Neither are very compassionate. However, we know that increasing the education of women consistently decreases the number of children these women have. In this approach we not only address the overpopulation problem, but also increase the quality of life for the women and their families. This is efficient compassion in action. 

Symbiotic relationships found in common mycorrhizal networks provide a fantastic template to follow. Those interested in emulating the Way of Fungi should look closely at this lifestyle choice to chart a path forward, tempering the ruthless efficiency of the “fungal managers” with the human trait of compassion. This would create a thriving, sustainable, and meaningful existence for us and all our neighbors - human and otherwise.