This is the third in a short series of essays about the origins of sex, inspired by my mentor, the biologist and geoscientist Lynn Margulis, one of my favorite philosophers, Michel Serres.
Part 2 was about the orgy of early life and how it reveals a counterpulse to identity. Part 3 is about the ultimate sexual merger: Symbiosis.
– Michel Serres
Life Superlives: On the Origins of Sex, Part 3
Life was born, and it superlived.
Early organisms brushed up against each other, and when they did, they consumed each other. But not always. Encounter after encounter between them gave rise to a new form of union: symbiosis.
Here’s an example. Imagine a tiny, ancient oxygen-respiring bacterium. Small, but hungry, it was was a fierce predator. Now imagine a larger, blobbier organism – a thermoplasm, contracting and expanding itself through its shapeless life. The two come together again and again, usually leading to the thermoplasm being invaded and eaten from the inside out by its smaller relative. But not every invasion killed the thermoplasm, and soon – how? We don’t know – the invader organism was taken up by the invaded, incorporated into its being. Permanently.
The thermoplasm could now resist the death-bringing properties of oxygen, and the bacterium found rest from the hunt.
Symbiosis is the ultimate procreative sex act. Two beings merge and form a third. Not a separate being, but a reincarnation of both selves.
Symbiosis is the origin of all multicellular organisms, and likely one of the main motivators of the rise of new species.
Symbiosis is sex, super-sexing.
This creative act is the foundation of human life. Let me explain.
Many protoctists (usually mislabeled “protozoans” – there is no “zoo” in them, since they aren’t animals) like the thermoplasm, reproduce through cell division, also called mitosis, in which an organism copies its own DNA and then pulls itself in two. A startling feature of mitosis is that, even though it’s called cell “division,” it doesn’t actually divide the number or chromosomes, structures in the cell that bear many of the cell’s genes.
In the procreative variety of sex that humans have, sperm and egg cells merge to create a new being. Sperm cells and egg cells have only half the chromosomes compared to the other cells in human beings. When sperm and egg meet, each carries a complimentary half of those chromosomes. This is how sperm and egg meet and form a new being. Rather than dividing (mitosis) humans are created by compliment (meiosis).
Our cells have forms that are meant to meet. They await each other. In other words, human beings are formed through a sort of predestined symbiosis.
Look at your hands, now. They are composed of cells upon cells, grouped together in the whorls and arches of your skin, the bones beneath, the connecting tendons. Your hands are a gathering of cells. And those cells are the ancient agreements of bacteria.
Sex is us. It’s what makes our cells, it’s what made us capable of making new forms of sex and new beings.
And it’s more than just us.
From its inception, sex has been a meeting of forces far beyond bodies and desires.
Next up: Sex Before Life.
Margulis, Lynn and Dorion Sagan. Microcosmos: Four Billion Years of Microbial Evolution. Berkeley: University of California Press, 1997.
Margulis, Lynn and Dorion Sagan. Origins of Sex: Three Billion Years of Genetic Recombination. New Haven: Yale University Press, 1990.
Margulis, Lynn and Dorion Sagan. What Is Sex? New York: Simon and Schuster, 1998.
Serres, Michel. Variations on the Body. Minneapolis: Univocal, 2012.