You See, Marriage Is a Mitochondrion
From an Ancient Mechanism of Responsibility to a Future Organ of Trust
1. Mitochondria Were Originally Outsiders
Mitochondria were not always organs inside the cell.
Today they sit so naturally inside the cell that they seem as if they had always belonged there. Whenever the cell makes energy, mitochondria work like obvious internal machinery.
But the beginning was different.
Mitochondria were originally independent beings outside the cell. At some point, they entered another cell, and over a long period of time they became the core organ that produces the cell's energy. They were not family from the beginning. They were not organs from the beginning.
Something outside entered the inside and eventually became an insider that moves life itself.
The first property this essay borrows from mitochondria is exactly this: the process by which an outside being becomes an insider.
Marriage can be seen again from this point.
Was marriage a system of love from the beginning? Or was it a device that brought someone who could remain outside into the family?
Sex involves two people, but pregnancy happens inside the woman's body. A child begins inside the woman's body, and the marks of childbirth first remain with her. By contrast, pregnancy leaves no such mark on the man's body.
So ancient society must have asked a question.
How can the risks of childbirth, which the woman may otherwise bear alone, also be tied to the man?
This essay begins from that question.
2. What Remains in the Body, and What Is Made to Remain in the Institution
To see marriage only as the result of love is too modern.
Today, we think of marriage as a matter of love, trust, companionship, and happiness. We say people marry because they love someone, because they want to live together, because they want to become each other's ally. In our time, that is partly true.
But the institution called marriage is far older than modern emotion.
If we imagine a time when contraception was weak, when it was difficult for women to live independently, and when raising a child could alter the entire course of one person's life, the starting point of marriage looks much more practical.
Sex involves two people, but the way its result remains in the body is not the same.
Pregnancy begins in the woman's body, and the marks of childbirth first remain with her.
A man participates in the same event, but it does not remain in his body in the same way.
This asymmetry could not simply be left alone.
So society tried not to leave the consequences of a relationship only in the body. It tried to leave them in an institution as well. It needed a way for the community to recognize who was connected to whom, and who would enter the circle of responsibility if a child was born.
Marriage may have been one of those devices.
Marriage did not begin only with the name of romance.
It may have been a way to make responsibility that did not remain in the body remain in society.
This is the starting point of the essay.
3. Marriage Grew From a Device Against Departure Into a Structure for Running the Family
With the rise of agriculture, the meaning of marriage grew larger.
In a world of hunting and gathering, the question of a child was a question of survival and care. But in an agricultural society, land, houses, livestock, stored food, property, and inheritance were added to it. A child was no longer only a question of who would feed and protect them. The child became a question of whose child they were, which household they belonged to, and whose property they would inherit.
Marriage became a stronger device at this point.
At first, it may have been a way to bind a man within the responsibility of a woman and child. But in agricultural society, that bond grew into a structure that fixed lineage, property, and household order. A man and a woman no longer existed only as individuals. They became husband and wife, father and mother, daughter-in-law and son-in-law, members of a household.
Here, a second property of mitochondria overlaps.
After entering the cell, mitochondria did not remain as guests. They took on the production of energy. An outside being entered the inside and began to perform a survival function.
Marriage did something similar. At first, it may have tied down the responsibility of a man who could leave. But over time, marriage became part of the family's energy structure. Making a living, raising children, maintaining the home, caring for the old, and passing down property all entered marriage.
Marriage grew from a device that prevented departure into a device that moved the family.
4. In Traditional Society, Marriage Was More Role Than Love
In traditional society, marriage was more about roles than emotions between two people.
Especially in the Confucian family order of East Asia, marriage was less a personal choice and more an event between households. Whom one loved mattered less than which household would be joined to which. Continuing the family line, honoring parents, maintaining ancestral rites, giving birth to children, and preserving the order of the clan stood at the center of marriage.
A married person first received a role before remaining simply an individual.
Husband.
Wife.
Daughter-in-law.
Son-in-law.
Father.
Mother.
Member of a household.
This structure resembles the way mitochondria entered the cell and no longer remained independent organisms, but became organs. Mitochondria still have some of their own DNA, but they lost many of the functions they would have had as independent organisms and now work inside the system of the whole cell. Biologically, the ancestors of mitochondria are also understood to have lost many genes or transferred them to the host nucleus after entering the cell, gradually integrating into the organelles we know today.
Traditional marriage had a similar quality.
A person does not vanish completely through marriage. But the function of the household grows larger than individual desire. A woman becomes a man's wife and a household's daughter-in-law. A man becomes a woman's husband and a household's son-in-law. When a child is born, the two are no longer merely lovers, nor merely a couple. They become organs inside the larger organism called family.
Traditional marriage gave people the name of a role before the name of love.
5. In the Modern Age, Love Entered Marriage and Its Functions Began to Leave
In traditional society, marriage was closer to a role than to love.
But after the modern age, as individual choice became more important, love began to enter marriage. The feeling that one wanted to choose the person one loved grew stronger than the old form of marriage arranged by parents and families. Marriage gradually moved from the command of the household to the choice of the individual.
What is interesting is that, around the same time love entered marriage, the functions marriage had carried began to move outside it one by one.
In the modern age, marriage changed again.
Contraception became possible. Women gained education and income. Divorce became possible. Living alone became possible. Sex was no longer treated simply as a presumed marital obligation, and marriage and childbirth began to separate. One could live without marrying, and one could marry without having children.
This change pulled the older functions of marriage outward one by one.
Sex was no longer treated simply as a presumed marital obligation.
Childbirth became a choice.
Survival was partly taken over by individual earning power and social systems.
Old-age support was partly shared by insurance, welfare, and care services.
The family clan no longer stood absolutely above the individual.
Then marriage begins to look empty.
In the past, marriage carried too many things. Sex, childbirth, childrearing, property, lineage, old age, legal guardianship, and social status were all inside marriage. Modern society begins to remove those functions one by one.
Mitochondria went through a similar path. They still carry traces of their origin as independent organisms, but after entering the cell, they lost many functions. Yet they did not disappear. Instead, they retained a core function: energy.
Marriage may move in the same way.
Even if many functions leave, one final function may remain.
Whom will I allow into the inside of my life?
6. DINK Couples Are Not a Counterexample to Marriage, but Evidence of Its Transformation
DINK couples raise an important question in this essay.
If marriage was originally a device for binding a man because of children, why do couples who do not have children still marry?
This question should not be avoided. It reveals the direction in which marriage has changed.
DINK couples are a form of marriage from which the childbirth function has been removed. From the viewpoint of older marriage, this looks strange. If a couple will not have children, why marry? If they will not continue a lineage, why become husband and wife? If there is no childbirth risk, why bind the relationship through an institution?
But from the viewpoint of modern marriage, DINK couples are not strange.
They show what remains when childbirth is removed from marriage.
What remains is trust.
What remains is legal family.
What remains is the position of being each other's guardian.
What remains is the relationship of planning the same home, the same life, and the same old age.
What remains is someone who is not a complete outsider when I collapse.
Ancient marriage tied a man because of children.
Modern marriage ties two people as family even without children.
This change matters.
Marriage is moving from an institution of childbirth to an institution of internal belonging.
7. Mitochondria Show the Future of Marriage
Then what will happen to marriage in the future?
Mitochondria show one possible direction.
Mitochondria lost many things. If they had once been independent organisms, they lost many of the functions they would have had and became organs that work only inside the cell. But that loss did not mean disappearance. Instead, only the core function remained, and that function became even more important.
Marriage may follow a similar path.
Future marriage may become less common than it is today. It may happen later. It may become a choice rather than a requirement. If sex, childbirth, survival, old-age care, and family pressure continue to move outside marriage, the reasons for which people must marry will decrease. In many societies, marriage rates have declined while cohabitation and diverse family forms have increased.
Within this flow, marriage may weaken.
But weakening does not necessarily mean disappearance.
Like mitochondria, marriage may lose many functions and keep only the core.
That core may not be childbirth.
It may not be lineage.
It may not be social respectability.
What remains to the end may be this:
Can I allow this person into the inside of my life?
Future marriage will not be a rite of passage everyone must complete. It will become a high-trust relationship into which not just anyone can enter.
8. Future Marriage Will Become Smaller and Heavier
Mitochondria are small. But they determine the energy of the cell.
Future marriage may become like that.
Marriage may become a less universal choice in society as a whole. But for those who choose it, the relationship may become heavier. In the past, many marriages were made because people needed them to live. In the future, marriage will be something people choose even though they can live without it.
To choose something one does not have to choose means that the standard of selection rises.
Not everyone is brought into the inside of one's life.
Not everyone is made family.
Not everyone is made a guardian of one's old age.
Not everyone is allowed to share money, illness, failure, parents, the possibility of children, and time.
Future marriage may decrease in number, but become more precise in meaning.
Older marriage bound people through necessity.
Future marriage will leave only those who pass through trust.
9. Future Marriage Will Be Symbiosis That Preserves One's Own DNA, Not Total Absorption
Mitochondria are inside the cell, but they still have some of their own DNA.
This point is also important for thinking about future marriage. Older marriage was closer to one person being absorbed into another household. In particular, women entered the husband's household and roles through marriage. Daughter-in-law, wife, and mother often came before the individual.
But future marriage is unlikely to move in that direction.
Future marriage will be less about one person being absorbed by another and more about two people preserving their individuality while forming one shared system of life energy.
My name.
My work.
My money.
My time.
My room.
My taste.
My relationships.
My thoughts.
These will remain even inside marriage.
Just as mitochondria became organs inside the cell without completely losing their own DNA, future spouses will become family without dissolving completely into one another.
Future marriage will move closer to "we create one system while keeping each self" than to "we are one."
10. As Long as Childbirth Remains, Women's Power of Selection Will Not Disappear
Mitochondria are usually inherited through the mother. In humans and many animals, mitochondrial DNA is mainly passed down through the maternal line, while sperm mitochondria are usually removed after fertilization or do not remain in the next generation.
This fact is strangely important when thinking about the future of marriage.
No matter how society changes, a child still begins inside the woman's body. The bodily risks of pregnancy and childbirth still first fall on the woman. As long as this asymmetry is not completely erased by technology, women's power of selection and caution will remain important in marriages that include childbirth.
The side that carries the greater risk chooses more carefully.
However, in marriages without children, DINK couples, unmarried cohabitation, and various companion relationships, this structure weakens. There, marriage moves from managing childbirth risk toward trust and shared life.
So future marriage may divide into two forms.
One is marriage that includes childbirth. Here, biological risk and responsibility remain.
The other is marriage that excludes childbirth. Here, trust, guardianship, and the meaning of shared life become clearer.
Marriage will not remain in only one form.
Just as mitochondria perform different functions in different cellular environments, marriage will differentiate into multiple forms.
11. A Good Marriage Is an Energy Organ, and a Bad Marriage Is a Failed Organ
When mitochondria fail, the whole cell is shaken. Mitochondrial diseases can disrupt energy production and seriously affect tissues that use a lot of energy, such as muscle, brain, and heart.
Marriage is similar.
Marriage is the act of bringing someone into the inside of one's life. A good marriage becomes life energy. Not simply because it brings more money. It stands beside a person when they collapse, goes to the hospital with them, knows their failures and still stays, and builds the rhythm of daily life together. A good marriage makes a person less lonely and helps preserve the energy of life.
But a bad marriage does the opposite.
When someone who has been brought inside breaks trust, one's whole life is shaken. Violence, betrayal, irresponsibility, financial collapse, and emotional exhaustion are not the problems of an outsider. They are the problems of someone already inside. That is why the wound goes deeper.
Future marriage will become colder about this point.
In the past, maintaining marriage itself was treated as a virtue.
In the future, the more important question will be whether the marriage creates energy for life or takes it away.
A good marriage is an energy organ.
A bad marriage is a failed organ.
12. Will Marriage Disappear, or Become Smaller and Leave Only Its Core?
Will marriage disappear in the future?
I think it is more likely to shrink than to disappear. More precisely, it may lose many functions and leave only its core.
Mitochondria did that. They lost many things, but they did not disappear. Instead, they remained as the core organ that provides the cell's energy.
Marriage may do the same.
Sex will no longer be treated simply as a presumed marital obligation.
Childbirth will become a choice.
Lineage will weaken.
Survival will be shared between individuals and social systems.
Old-age care will be partly replaced by services and technology.
But there is something that cannot easily be replaced.
Who is the person inside my life?
Who is my guardian when I am ill?
Who stays even after knowing my failure?
Who remembers my long history?
Who shares the energy of the same home with me?
These questions will not easily disappear.
That is why future marriage will not be a system everyone must enter, but a relationship not everyone can enter. It may become less common than before. It may happen later. It may break more often. It may divide into more diverse forms. But the marriages that remain will become clearer.
In the past, necessity bound people.
In the present, trust leaves people as family.
In the future, only the person who passes even through that trust will become the mitochondrion of my life.
References and Sources
1. Nature Scitable, "The Origin of Mitochondria." Explanation of the endosymbiotic origin of mitochondria and ATP production. https://www.nature.com/scitable/topicpage/the-origin-of-mitochondria-14232356/ 2. Roger et al., "The Origin and Diversification of Mitochondria," Current Biology, 2017. Explanation of the common ancestry of mitochondria and their alphaproteobacterial lineage. https://www.sciencedirect.com/science/article/pii/S096098221731179X 3. Martin et al., "Endosymbiotic theories for eukaryote origin," Philosophical Transactions of the Royal Society B, 2015. Overview of multiple endosymbiotic models for mitochondrial origin. https://pmc.ncbi.nlm.nih.gov/articles/PMC4571569/ 4. Human Relations Area Files, "Marriage and Family." Explanation of marriage as a socially recognized sexual and economic union involving rights and obligations. https://hraf.yale.edu/ehc/summaries/marriage-and-family 5. OpenStax Anthropology, "Marriage and Families across Cultures." Explanation of marriage as an official structure for childrearing, while noting that it cannot be reduced only to reproduction. https://openstax.org/books/introduction-anthropology/pages/11-4-marriage-and-families-across-cultures 6. Pew Research Center, "Marriage and Cohabitation in the U.S." Trends in declining marriage rates and rising cohabitation. https://www.pewresearch.org/social-trends/2019/11/06/marriage-and-cohabitation-in-the-u-s/ 7. OECD, "Korea's Unborn Future." Analysis of South Korea's low fertility, work-family conflict, and gendered role burdens. https://www.oecd.org/content/dam/oecd/en/publications/reports/2025/03/korea-s-unborn-future_1b836111/005ce8f7-en.pdf
An Seungwon / Wonbrand / https://wonbrand.co.kr