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Non-hierarchical Microbial Ecologies; or Everything is Everything

I’m fascinated by the story of Lynn Margulis, an evolutionary biologist whose theory on endosymbiosis is considered one of the great achievements of 20th century evolutionary biology. Originally met with great skepticism, it has since been validated through experimentation thanks to advancements in molecular methods. She opposed the idea that competition was the primary driving force of evolution, as was the currently accepted Darwinian standard, and asserted that symbiosis and cooperation were actually the main mechanisms of evolution.

Symbiosis is when different organisms come and live together. It is any sort of close biological interaction between 2 different biological organisms, with any sort of benefit/cost relationship. These include mutualism (mutually beneficial), commensalism (one benefits, the other is neutral), and parasitism (one benefits at the expense of the other). Cooperation is when organisms work together for a collective benefit, and this can be mutually beneficial or altruistic in nature.

The theory of endosymbiosis says that the mitochondria in our human cells were originally free living bacterium that were swallowed up by another organism. It decided to crash on the couch in exchange for respiring oxygen and producing energy, and made itself at home for good. Same thing with plants – the chloroplasts in plant cells were originally free living photosynthetic bacteria that were swallowed up by another bacteria. A place to crash in exchange for a solar power plant, essentially, transforming sunlight into energy. And, the creation of a new species through the collectivization and integration of individuals coming together. Evidence that the mechanisms of symbiosis and cooperation contribute to the evolution of new species.

Bottom cell with mitochondrion = the basis of our human cells; Top cell with green chloroplast (photosynthesis) = the basis of plant cells

Along those lines, she also asserts that multi-cellular organisms evolved out of cooperatives of bacteria. Our brain cells and blood cells were once specialized bacteria of their own kind, that came together and found better collective fitness living and working together. In another “few million years, for example, the microorganisms producing vitamin B12 in our intestines may become parts of our own cells. An aggregate of specialized cells may become an organ.” (Microcosmos, p. 33)

She has a reputation as being a rebel scientist, as her theories later in life were increasingly controversial. She was married to Carl Sagan for a few years, and had two children with him. She said it was impossible to have a relationship, children, and a successful career in science all at once.

She applied her understanding of evolutionary ecology to human politics as well:

“As symbolized by the deconstruction of the Berlin Wall and the end of the Cold War, it is folly not to extend the lessons of evolution and ecology to the human and political realm. Life is not merely a murderous game in which cheating and killing insure the injection of the rogue’s genes into the next generation, but it is also a symbiotic, cooperative venture in which partners triumph. Indeed, despite the belittling of humanity that naturally occurs when one looks at “Homo sapiens sapiens” from a planetary perspective of billions of years of cell evolution, we can rescue for ourselves some of our old evolutionary grandeur when we recognize our species not as lords but as partners: we are in mute, incontrovertible partnership with the photosynthetic organisms that feed us, the gas producers that provide oxygen, and the heterotrophic bacteria and fungi that remove and convert our waste. No political will or technological advance call dissolve that partnership.” (Microcosmos, p. 16)

While her predecessors had spoken of the evolutionary advancement and importance of humankind, in her view humanity was “simply one among other microbial phenomena” (p. 19), and she believed there were no solid boundaries or distinctions between humans and microbes.

“In Microcosmos we take a stance against the division of human beings from the rest of “Nature.” People are neither fundamentally in conflict with nor essential to the global ecosystem. Even if we accomplish the extraterrestrial expansion of life, it will not be to the credit of humanity as humanity. Rather it will be to the credit of humanity as a symbiotically evolving, globally interconnected, technologically enhanced, microbially based system.” (p. 19)

She asserts that there is no hierarchy between humans and microbes – we often think of humans as being on the top of the evolutionary pyramid, and microbes at the bottom. But if we are simply mass vehicles of microbial communities, then we are not really on the top of the evolutionary pyramid. And, it is not about inverting the pyramid either.

“The problem with the reversal that places microbes on top and people underneath is that dichotomization – important versus unimportant, essential versus unessential – remains. […] Confronting our ecological arrogance does not solve the problem of the pedestal: it is still assumed that one organism is better, higher, or “more evolved” than the other. Once we recognize our energetic and chemical intercourse with other species, however, and the nonnegotiability of our connections with them, we must remove the pedestal altogether.” (p. 21)

I imagine overlapping circles of shifting landscapes of microbial communities. This challenges ideas about our identities as being solid, unique, and independent. It pokes holes in our boundaries between ourselves and the world around us, our relationship to other living beings. It would seem as though we are simply a shaping point in a sea of microbes. Everything is everything, there is no such thing as not being affected by things happening outside of ourselves, or in other parts of the world.

I find it interesting that in her research on microbial ecology and evolution, she stumbled upon ideas around political structures and hierarchy. For those who think science and policy should be separate, distinct fields of study and education, perhaps our microbial ecologies already have their own political structures in place, upon which they rely for their cooperation, organization, and collective evolution. Perhaps if we are thinking of evolving more collectivist and cooperative models of decision-making and living and working together, we could stand to learn a few tips from our microbial comrades.

I opened up my 2nd class in Soilify on the Role of Soil in Climate, Human, and Community Well-being with a look at this work by Lynn Margulis. You can learn more about it there, as well as modern microbiome research, and other principles in microbial ecologies that relate to our health and well-being.