Population Control — Human and Animal

Do populations in nature self-regulate? I believe so, and have adduced evidence from field studies and from computer simulations. Indigenous human societies, too, effectively kept our numbers in check for our first million years during which people were part of nature. Now people have moved on from nature, and we’ve lost the intuitions that helped us to regulate our numbers. Do we need a global government that surveils our bedrooms and mandates selective abortions? No — this is a cure worse than the disease. What we need is a return to the attitudes and sensitivities that enables us to live in harmony with Gaia.

In the 21st century, I have written that ecosystems are self-regulating— not via some invisible hand that creates homeostasis out of selfishness, but by evolved individual behaviors that dampen population explosions and prevent population crashes.

Sixty years ago, a British naturalist with far more cred than I’ll ever have said the same thing, and he was canceled by an academic establishment that brooks no dissent. They theorize that selfish genes are the be-all and end-all of evolution, and they ruled the province of evolutionary science with an iron fist through the second half of the 20th century. From their perspective, fitness consists in leaving more offspring than your neighbors. The idea that natural selection could lead to voluntary limits on reproduction is (for them) a non-starter.

And yet, population control is an essential feature of ecology. The truth is that birth control and “death control” in the form of lifespans limited by aging are crucial to the very survival of ecosystems. (The origin of aging as a mechanism of population stabilization has been the subject of my principal contribution to the literature of evolutionary ecology. My book)

The mechanisms of population control in animal species are widely studied and discussed — though it is taboo to point out that they obviously violate the “selfish gene” paradigm. The most common mechanism is territoriality. A bird family or a pack of wolves will hold its territory and prevent others from encroaching, thus preserving a generous food supply for itself and its kin, while keeping out the competition.

It is easy for Darwinian fundamentalists to understand the motivation of the selfish, hoarding behavior. What they can’t explain is why other birds or wolves go along with it. Why aren’t there more fights to the death, considering that 100% of a challenger’s Darwinian fitness hangs in the balance?

But birds and even tigers seldom fight. There is a legendary study by Stewart and Aldrich [1951], who found that for every mating pair of songbirds in a nest, there are a dozen or more birds cruising the periphery, waiting in the wings, so to speak, for a vacancy so they can build a nest. Somehow, the birds have all agreed to keep the breeding population constant, generation after generation, even as the non-breeding population waxes and wanes and even crashes. It’s a marvelously effective system for ecosystem homeostasis, but the mystery is how and why the birds agree to be bound by the rules. In particular, the majority of birds submit without protest to a convention that has zeroed out their Darwinian fitness.

Lori Stevens [1989] described beetles that cannibalizing their young under conditions of overcrowding.

In a famous experiment with Mouse Utopia, John Calhoun provided everything that his rats (later mice) needed to live — plenty of water and food, exercise wheels and playgrounds, in an environment free of disease and predators. Only living space was limited. Time after time, he watched the population expand exponentially, until these highly social animals became highly anti-social. They fought, bit and scratched, failed to protect their young, and eventually the entire colony collapsed to zero — all while the experimenters continued to provide an abundance of food for everyone.

Animals understand ecology

Back in 1968, just before it became taboo to write such a paper, Stonybrook ecologist Larry Slobodkin wrote “How to be a Predator”. The title was ironic, because his conclusion — backed by both mathematical models and common sense — is that the most important thing for a predator is to keep the population of prey near its maximum. It is tempting for any individual to take more than his share of prey, to use the extra energy to create more offspring, and thus to advance the interest of his “selfish genes”. But what if he succeeds? Then his offspring increase exponentially, and they come to dominate the predator population in just a few short generations. Then they find themselves competing with their own greedy cousins for a dwindling prey population. Mass starvation is unavoidable.

Can we be surprised that evolution learned this lesson early and often? Any population of animals that shares a common food source is forced to cooperate in order to keep their numbers under control. Failure to obey is punished by extinction, and extinction is the ne plus ultra of natural selection. This is a language that even neo-Darwinist dogmatists should understand. But many of them consider every evolved altruistic behavior to be a deep mystery.

Early humans

Curiously, the means by which human groups maintained population homeostasis for our first million years on the planet are less well understood. If you ask an anthropologist how indigenous cultures kept their populations in check, he will probably answer, “war”. No doubt, there is plenty of carnage in human history as we know it, but the history we know is less than 1% of man’s tenure on the planet. We know precious little about earlier human cultures, and in the absence of specific knowledge my guess would be that humans, like animals, had instincts that told them when reproduction would be counterproductive for the community. Various tribal cultures all had unwritten rules about who could reproduce, when, and how much. Human groups are imaginative beyond our imaginings, and it is likely (IMHO) that each tribe had its unique traditions and covenants that contributed to population stability without excessive violence.

I’m personally attracted to the idea that before Columbus, indigenous Americans had learned to be stewards of nature, to manage prolific ecosystems that provided their needs without the monoculture and livestock technologies that predominated in Eurasia. [Charles C. Mann]

Whatever it was that enabled tribal populations to thrive in harmonious relationship to diverse ecosystems, this knowledge has been lost, along with the motivation and the will to maintain harmony with nature as a condition of human existence. Human population is out of control these last several hundred years. Combined with an exploitative mentality and industrial means of destruction, exponential population growth is an existential threat to humanity. But there is no way out of this dilemma that does not violate our deeply held convictions about human rights and autonomy over our own bodies. Or so it seemed…


In Britain and America in the early 20th century, liberal intellectuals all received Darwin’s memo about the necessary pruning of the weak, and they realized that that was no longer morally acceptable to our civilized sensibilities. How then to preserve and even improve the human gene pool? Eugenics was part of the credo of the time: the state must take control, and apply meritocratic principles to determine who is allowed to have children. Then Hitler came along and gave eugenics a bad name.

In the 1970s, Paul Ehrlich and the Club of Rome warned us of an impending “population bomb”, timed to destroy humanity via starvation before the century was out. Population control again became thinkable. Then Mao tried it, with results that were wildly unpopular, even in the context of a docile Chinese culture that was conditioned to obey central authority. China is living today with the legacy of the one child policy. There are not enough women for the men who wish to marry, and it is projected that there will be not enough working people to support the generation coming to retirement age. But the results of the one-child experiment were not all bad. A generation of Chinese had excess income, in part because they did not have large families to support, and this contributed to an unparalleled wave of prosperity that lifted a billion people out of poverty. Freed from having to grow rice for a burgeoning population, peasants migrated to the cities to build an industrial powerhouse.

Some of us trust government more than others, but almost everyone is horrified at the prospect of a technocratic committee deciding who is allowed to have children, and when, and how many.

I like to tell the story of Sir Ronald Fisher (1890-1962). He was a brilliant man who integrated Mendel’s genetics with Darwin’s selection to create a mathematical theory of evolution that stands to this day. And along the way, he contributed most of the statistical methodology that is widely used in biology today, and also in medicine, astronomy, paleontology, etc.

What motivated Fisher more than anything was a passion for eugenics. He was convinced that his own peers of the British aristocracy were not having enough children, while the hoi-polloi were having too many, and that British culture would not survive the dilution of the gene pool. He fathered eight children. Fisher wrote just one book; the first half has served as text for a quantitative theory of evolution, and the second half is an embarrassing, racist screed.

Fisher’s evolutionary theory was the selfish gene. The term was not coined until Richard Dawkins wrote a popular book 40 years later, but the ideas were all Fisher’s. Fisher’s evolution is sometimes called “population genetics” or “neo-Darwinism”. It is a paradigm that turned evolution into a testable, quantitative theory; but it also became a rigid dogma that still holds the field back today. The Chinese translation of my book is called 无私的基因, The Unselfish Gene.

Tragedy of the Commons

In 1968, ecology professor Garrett Hardin captured the spirit of his time in a Science Magazine essay called The Tragedy of the Commons. In a mythic village where everyone’s sheep graze together on an ample acreage of lush grass, each farmer is motivated to increase his own herd size. And when the grass becomes thin and the sheep grow leaner, the motivation to increase each farmer’s individual share only grows stronger. The situation quickly escalates to the point where all the sheep starve.

Therefore (Hardin concluded), all it takes is for everyone to be pursuing his own enlightened self-interest in an enlightened and peaceful manner, and the human experiment will proceed to a suicidal end.

How many people can the Earth support?

I don’t pretend to know the answer, and I’m suspicious of anyone who tries to calculate a number. I have written about the possibility that transformative energy technologies are already known to some subset of the human population. Even without free energy, we might cram our apartment buildings ever higher and denser and grow hydroponic soy protein in our photovoltaic deserts. You might agree with me that this isn’t the world we want to bequeath our grandchildren.

Laws restricting abortion have inflamed some of the most divisive passions in American politics. Can you imagine if the Federal government tried to mandate abortion? You would have the entire Woke establishment and a feminist army lining up alongside the Pope and the Christian Right to say NO!

But we live on a finite planet.


With clear, logical reasoning, it’s easy to convince ourselves that overpopulation is a hopeless problem. So, let me offer some fuzzy, illogical reasoning…

Urgency — It’s long past time to prevent damage to global ecosystems — we must begin ASAP to pick up our garbage and allow them to recover. We can do this much more quickly than we can reduce the world’s population. For example, Amory Lovins has showed us how to do this in the energy sector. We need to rein in the excesses of capitalism in externalizing the costs of doing business. The principal obstacle is the extent to which “democratic” governments have been captured by corporate influence. Our failure to prevent toxic waste and wasteful consumption is a failure of democracy, not a problem of overpopulation.

The Malthusian death spiral — 200 years after Malthus, world population has grown eightfold, but we are better able to feed the world than we were in 1800. We have inexcusable starvation in large regions of the world, but this is a tragic result of inequitable distribution and imperial exploitation, not a technical problem of food production. Counting just the grains that are stored in mega-silos and sold on world markets, we produce almost twice as many calories as 8 billion people need.

There is a myth that the “green revolution” has saved humanity from starvation. But mechanized agriculture, chemical pesticides, and factory farms are efficient only when accounted in dollars. Agribusiness has optimized for yield per man-hour, not yield per acre. Small farmers using traditional and sustainable methods could further increase yields. [Vandana Shiva]

The win-win path to population control — In Russia, Japan, and Italy, fertility is below replacement, and that is concerning to people who cherish the rich cultural traditions of these nations. Some of the reason is despair for the future. But the most promising reason for declining fertility is that people feel secure in their future and fulfilled in their lives outside the family.

Fertility explodes in controlled, exploited populations. Fertility declines when people have a social safety net to care for them in their old age. Fertility declines in stable, prosperous economies. Fertility declines when women have fulfilling careers outside the home. Bill Ryerson has devoted his career to slowing population growth by educating and empowering women.

Let’s continue to work toward more livable communities, especially for women, and the “population problem” just might take care of itself.

10 thoughts on “Population Control — Human and Animal

  1. You took my ideas from the last comment and ran with them, I see, JM

    There is no population problem and there never was. There is a fake monetary system (fiat) and increasing efficiency with questionable, global labor practices … and without survival issues for so many for over 80 years, we’ve now turned into a gynocentric society that is ripe for collapse (see The Fate of Empires). I find it weird that people cheer for depopulation and promote the increased probability of death for others, while at the same time maintaining different rules for themselves. Ever notice how they don’t start with themselves in order to reduce the population? Funny how that works …

  2. ‘Curiously, the means by which human groups maintained population homeostasis for our first million years on the planet are less well understood.’

    Primitive groups of humans live in groups where all children are loved and nurtured to an extent modern people cannot understand (because it would be too condemning of our current lifestyle to think about). In these conditions, people grow up loving, open and selfless.

    ‘Fertility declines when women have fulfilling careers outside the home.’

    Fertility has declined because women can’t possibly be both effective mothers and have a rewarding career. It is just too much and no-one can cope with the increased demands. Anyone who has a family knows this.

    • Yes, it’s curious that JM made a comment about something being livable, “especially for women” as this is the most artificially livable time ever in the developed world, especially for women. It’s pretty clear what’s going on from a global point of view, but sadly we’re entering the crisis era anyway, as individuals don’t have as much say in the system – one that is a wounded beast at this point.

  3. I agree that people are less inclined to have children if they feel secure in their ability to provide for themselves when young or older

    Adding to the self-regulating concept, as highlighted in your article by the reference to: “Lori Stevens [1989] described beetles that cannibalize their young under conditions of overcrowding.”

    Baby eagles in a nest will kill a sibling to get more food for themselves from the parents.

    Also, I have seen small birds, with a full nest, push some offspring out of the nest. Perhaps the baby bird is sick and they this to not infect the others or to provide more food for some of the healthiest offspring, if the brood is too large for the parents to handle.

    I witnessed a mother bird do this once, much to my horror. I tried to save the featherless bird that fell from a low branch to the grass. I kept it comfortable, warm, watered and fed, as described by a wildlife “rehabber”, but the tiny creature died a few days later.

    • Humans are much more loving than other animals. Or at least we are in the conditions in which we evolved. This is something very hard for people wedded to the ‘survival of the fittest’ concept to understand. It is something trained into us by the nurturing (mothering) process, with our genetics then evolving to expect it. It is also silly to try and explain such behaviour through ‘group selection’. It is first and foremost psychological and only secondarily genetic (as in, the child comes to look and act more childlike because of the conditions of nurturing, not the other way around).

        • Of course it includes Golden Retrievers. Dogs reduce violence by being in a hierarchy. That is just survival of the fittest with reduced fighting for the pecking order. Humans are capable of genuine altruistic behaviour (as well as quite hideous behaviour, of course).

          • Based on my own experience, I have to disagree that SOME dogs are NOT capable of being just as loving, or more loving than some humans.

            I took in a 100-pound,10-year-old Labrador Retriever from a horse farm across the street, after the owner sold his farm.

            The farmer used to let the dog run free. The dog would visit me at my home, when I was spreading mulch and watering trees. He followed me from tree to tree, waiting patiently until I spread the mulch, then picked up the wheelbarrow to move to the next spot.

            He was fearful of loud gun shots, because he had witnessed hunters shoot deer, according to the farmer.

            After I took him in, one fourth of July, My husband and I were taking a walk with him. We heard loud firecrackers and the dog became anxious. I think he thought they were gun shots. He jumped in front of both of us, stood on his hide legs and repeatedly tried to push us back.

            We tried to tell him it was okay, and continued to walk, but he kept standing up and trying to alternately push us both back, away from the firecracker sound.

            He could have simply run home, to save himself. But he did not. Finally realizing what was likely going on, we turned around to go home, to let him know he was heard and his effort appreciated.

            In addition, once on our daily walks, I heard a loud UPS truck approaching, from behind. It was in the center of the street. Still, the dog suddenly moved from the grass into the street side, firmly nudging me away from the street and onto the grass by pushing his body against my legs, until the truck passed.

            Those actions seem like loving, selfless behaviors, IMO.

            The dog was also protective of our hissing orphaned Tabby cat, even though she was definitely NOT a very loving or selfless creature.

            Lastly, before we owned him, on his visits, If I gave him a biscuit, he would throw it down and push his head under my hand seeking to be petted. It was as if he were trying to show that he did not simply come over for the biscuit.

            Of course, like any self-respecting dog, he would eventually pick up the biscuit before trotting off back to his farm.

            He lived to be almost 18, so I have more examples like this, but you get the picture.

            Yes, I have been accused of anthropomorphizing when I share my interpretation of these behaviors. I don’t agree.

          • Dogs have nothing on Bonobos. Most unbelievably loving creatures you can imagine. And all built on the nurturing of their young and the gathering of their groups around mothers and children. And humans are descended from creatures like them.

            Of course dogs can display caring behaviour, on their level. There is a safety and security in being part of a pack and working together. But this is all instinctive behaviour. Humans are currently trying to build this co-operation consciously, i.e., not based on genetics. That is the distinction I am trying to make.

  4. Mark, it seems you are getting at the problem being a lineage/genetic and spiritual problem, since those are hard to disentangle, but stressing the fact that groups show overwhelming differences in such traits. Elites or the managerial class have many insights on how “hackable” the human (mass man) is, and the only counter to this, as I see, is how advanced in spirit and/or personality you are to see what’s going on – versus fall prey to going along with the crowd or materialism. Typically that comes in families or religious people, to an extent, I’ve noticed.

    It seems to me that human hierarchy is actively seeking massive population reduction. Psychological operations were already instituted but the sarscov2 thing was so obviously a scheme and scam of epic (and murderous) proportions, I can’t imagine at this point why someone can’t see it, unless they were the “prey” type I just mentioned last paragraph.

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