Our experience of the world is mediated through stories. Stories (also called theories by those who need a patina of scientific respectability) tell us how the world came to be, how it works, and what its fundamental rules are. Once is a while, someone comes along who so fundamentally changes the nature of our guiding stories that our life experience is transformed. Lynn Margulis, who died two days ago, is such a person.
Margulis taught us the importance of symbiosis in biology — the union of two or more different species into a new form. Her views were dismissed, ridiculed, and ignored for years. Finally, some of her ideas prevailed, although she continued to receive sniper fire for her penchant for questioning dogma.
Now, thanks largely to her, we understand that every living species is, at some level, the result of symbiotic fusion and union: all animal, plant and fungal cells have ancient bacterial cooperators hidden within; trees are united to fungal helpers below-ground; the animals that build coral reefs cannot survival without algal partners; insects are partly nourished by symbiotic gut bacteria; and even DNA itself appears to jump among species, intertwining radically “different” species into new entities. These processes happen in every part of life’s delta, but are particularly powerful among Margulis’ favorite creatures, the so-called “microbes” (the true “99%”).
Our metaphors have to shift. The “tree” of life? No, life has too many cross-connections among distant branches. An unstable, flowing delta is a better image. Evolution as a capitalistic competition among individuals? No, there are as many unions as robber barons; self-interested cooperation is rife.
As a small homage to Margulis, here are some of my DNA sequence data from the mitochondria of land snails. These are the color-coded “letters” of the DNA alphabet found within the ancient bacteria that live inside every cell in a snail’s body. But this description is misleading: the bacterial cells truly don’t “live inside,” instead they have melted their bodies into the other, creating an individuality-destroying symbiosis. Thank you, Lynn Margulis.
Each row is the DNA from one individual. Each column is one position along the DNA stand. The different "letters," A, T, C, and G, are color-coded.
For more on Margulis’ life, see John Horgan’s blog entry at Scientific American. He has some nice insights. The NY Times has a shorter obituary.
David George Haskell 
Thank you for this, David. Having not taken science beyond my freshman year in college, I have long found myself fascinated by everything I missed, both by education and by age. I was among the first high school students to be exposed “experimentally” to DNA, and I well remember it rocked my world then. When I entered college, I thought I’d be a molecular biology major, but the humanities called me instead. I can’t help wondering how much of our “knowledge” is shaped by our western cultural notions and expectations that predispose us to hierarchies in everything. I really enjoyed reading this post.
…glad you enjoyed the post. I think our love of hierarchy is a blessing and a curse: it helps us to see patterns and understand the world a bit better, but paradoxically it can also get in the way when we try to impose it where it does not belong. The reticulate patterns of evolution are imperfectly represented in a hierarchy. Now that we’re all getting more familiar with the potential of “networks,” our stories about how the world works will undoubtedly change.
Thank you, David. What vital and insightful work she did, and what a great reminder not to fall into the anti-heritical mindset in the sciences–or of any other disciplines.