Population on a Finite World: A zero-sum game with no vacancies.

Synopsis: The last “garden of Eden scenario” ended long ago, and population growth is a zero-sum game.

As I grew up during period when the human population had been growing rapidly for a seemingly countless number of generations, it felt like the population growth of the 20th century was normal. As a child I assumed that humans and many other species were still “growing into” environments that were just waiting to be colonised by humans and other species. I effectively thought that humans and other life was still populating the planet in a “garden of Eden” scenario.

It took a long time for me to realise how that thinking doesn’t add up, and to realise just how different my initial assumption was from reality.

Once I reached the first step by realising that the populations of other species were not increasing, that started the realisation. This population growth just about humans. Thinking about it more closely, it became clear that the Earth is really too old for species to be still growing into environments, and as all ‘vacancies’ should already be filled population growth should have reached its endpoint long ago. Yet, the human population did seem to have been growing throughout history. How could this be?

The contradictions led me to embark on a deeper analysis reality of how species reach population levels, and why is it that humans alone seem to be still increasing in population. The result of that research is below:

• Rules of population on our Finite Planet.
  1. The last “garden of Eden event” creating significant extra total on Earth ended 540 million years ago resulting in a zero-sum game with no vacancies since that time.
  2. Since peak life just after that last “Eden” event, “evictions” of other species and mass extinction events have been the only paths to create the vacancies for population growth.
  3. Mass extinction events highlight how quickly vacancies fill and populations stabilise.
  4. No Vacancy ever requires more than 100 population doublings to become fully occupied.
  5. Almost every species, humans included only needs at most 10,000 years for sufficient population doublings to fill any temporary vacancy.
  6. Advanced species control population through birth-rates to avoid starvation.
  7. Once a species reaches it limit further population growth requires evolution the species or changes to the environment.

In summary, for over 500 million years, total life on Earth has not increased which has made population growth a zero-sum game where species can only grow their population by outcompeting other species leading to reduction of population of other species as in “survival of the fittest”.

it turns out nearly every species is capable of reproducing population doubling within around 100 years, at a rate that if unchecked would result in that species covering the entire surface of this finite planet within far less than 100,000 years. This means every species has more than enough time to fully populate its niche within the environment.

While our planet is over 4-billion-years-old, the planet has not always supported life as we know it today, which new events in the history of the planet creating new “gardens of Eden” scenarios for life to bloom. However, the most recent “garden of Eden event” that allowed for an increase in the total amount of life happened over 500 million years ago, and the planet reached “no vacancy” statures almost immediately afterwards.

New species have arisen, but as the total amount of life is now decreasing, these new species could only create their own vacancies through the “eviction” of older species.

As Darwin declare evolution is about the “survival of the fittest”, and further increases in population require a species becoming more competitive or to become able in more environments. Either species get a boost from a favourable environmental change, or the species must evolve to become more competitive.

So how does this fit with humans? Humans are becoming more competitive! While 30,000 years ago humans were prey to many animals, humans of the 21st century and defeat and take over the environment of any other mammal, despite being biologically an almost unchanged species.

Humans exhibit accessorised evolution, which changes our ability to compete with other species and has even resulted in the Anthropocene epoch because now dominate the planet.

Continued accessorised evolution could enable humans to keep growing in population until the species of humans, their pets and their food are the only species in every environmental niche of interest to humans. But humans are still limited by the total biosphere, and with increasingly smaller populations of other species that compete for the environment, further gains for the human population become increasingly difficult both for humans, and for the species that must be displaced to make room.

How the human population had been growing even before the recent population explosion is covered elsewhere and the analysis of how populations grow on an already fully occupied planet as examined in the section below titled: What about humans? Are We exempt from these rules?

The conclusion is that we are not exempt from the rules, and even without climate change causing CO₂ emissions and our pollution, growing total biomass of not just humans but our food supplies, pets and gardens, and environment reducing urban landscapes, means that the total biomass of the rest of the biosphere must contract. Lower numbers of the total of all other species are the inevitable consequence of increased human population size.

If our mission is to perpetually deliver economic growth, as opposed to wealth per person, then yes, continual population growth is the simplest path to that mission, but as the level of population allowing access to all resources has been reached, further population growth will normally result in a decline in per capita average living standards.

It may be that at some point, it feels like humanity is being ‘farmed’ to generate wealth for a small subset of people, and at some point, our “farm” will start to feel crowded to the point of existing like battery hens, rather than having our free range.

Zero-Sum Game?

Since gaining more understanding of the term “zero-sum game”, I find it very appropriate to describe the situation with population, but not everyone is familiar with the term, and it is not fully self-explanatory.

Zero-sum game is a mathematical representation in game theory and economic theory of a situation that involves two sides, where the result is an advantage for one side and an equivalent loss for the other.^[1] In other words, player one’s gain is equivalent to player two’s loss, with the result that the net improvement in benefit of the game is zero.^[2]

If the total gains of the participants are added up, and the total losses are subtracted, they will sum to zero. Thus, cutting a cake, where taking a more significant piece reduces the amount of cake available for others as much as it increases the amount available for that taker, is a zero-sum game if all participants value each unit of cake equally.

Wikipedia page: Zero-sum game.

I feel that extract from Wikipedia at the time of writing sums things up well. Population on Earth is a zero-sum game when all life is valued equally. As humans, we may value humans more than other living things, but I believe should be aware that we are dealing with a finite sized “cake” rather than a growing cake, and that our gain is always a loss for some other species.

Rules of population on our Finite Planet

Rule 1: The last “Garden of Eden event” with new vacancies was 500 million years ago.

I am using the label “garden of Eden event” for when a new environment first becomes viable for life. In the terminology used in the “zero-sum game” section, the baking of more cake.

While the Earth is over 4 billion years old, most of those 4 billion years on Earth a human would have needed to wear a spacesuit to survive on the surface.

Different habitats have become first viable at different points in time, and/or life may have evolved the ability to exist in new environments at different points in time. Complex life on land was viable from only less than 0.5 billion years ago.

These events create “vacancies” for one or more species, either through changes to the environment of the planet that enable life to exist in one or more previously uninhabited niches, and/or thought evolution of new species able to inhabit one or more previously uninhabited niche(s).

Whether a person believes a God is involved or not does not change that there have been 4 major events that each created a “garden of Eden scenario” as they provided one or more species with an initially vacant environment to colonise and “go forth and multiply” up to the limit of that environment in the manner considered in rule 1 and rule 2.

Each garden of Eden event means populations can grow where they did not exist before and will result in increased total life on Earth.

Once all vacancies are filled, the total amount of life would remain stable as long as the environment also remains stable, and no new species evolve capable of inhabiting new niches within the environment.

The graph of history of the cumulative biosphere misses the first “garden of Eden” even over 3.5 billion years ago as records from the time are not available suggests that first wave of early life may have seen its environment deteriorating causing numbers to decline, before new species began appearing resulting in a second “garden or Eden event” as total life increased between from around 3 billion to 2.8 billion years ago, when that second garden of Eden event ended with the peak of procaryote life which continued until the Eucaryotes arrived into the third garden or Eden event and a third surge in the total amount of life. Things again stabilised until the fourth third surge in total life around 0.5 billion years ago and most recent “garden of Eden event” when complex life evolved.

It turns out, that since this most recent 4th “garden of Eden Event” there have been no significant long “vacancies” for species to grow their population the biosphere and total life is in fact decreasing as environment slowly deteriorates, as explained in the timeline of the solar system paper, but instead the total of all life on Earth has been in gradual decline for the past 540 million years.

Without some new expansion of the environment where life on this planet can exits, it seems unlikely that any increase in total life will again be possible.

Rule 2: For 500 million years, “Evictions” of other species and mass extinctions have been the only path to long term population growth.

In the absence of new “Garden of Eden events” or mass extinctions, the only option for major population growth has been through evolution allowing new or improved species to take over as the new “fittest” within one or more environment niches. Vacancies are not required if you can evict the current occupants.

Population growth from garden of Eden events can be seen from the history of total biosphere, while mass extinction events result in a change of species within the biomass, but no long-term change in total biomass.

The arrival of the Eukaryotes not only increased total life, but also resulted is a gradual reduction in the total population of procaryotes species. Clearly, there were also examples of Eukaryotes “evicting” procaryotes.

The arrival of complex multicellular life provides a far clearer example of how both procaryotes and eucaryotes suffered a dramatic fall in total population when face with “eviction” by the more evolved “fitter” complex multicellular rivals. The clearer immediate fall in population of previous species may be a result of the better data from this more recent time, but it may also be that complex life was a more immediate step forward.

We also know that a constant stream of new species arrived and grew to have significant population without needing to increase total life. In fact, for the entire history of life from arrival of the first complex life, none of the huge number of new species ever resulted in a significant boom in total life, and thus all grew their population at the expense of species previously occupying their same environment.

What we see is that the only times total life significantly increased, was in the very early stages of each garden of Eden event, and throughout tall the rest of evolution, the arrival of a new “fittest” result in a corresponding reduction in the total numbers of other species.

In the entire 540 million years since the environment for life expanded at the start of the Phanerozoic Era, all population growth within any species has resulted in a corresponding decrease in the population of other species, which means the only path to an increased population is to gain more “fitness” over other species through evolution.

The first land plants and animals appeared in an expansion of life around the beginning of the Phanerozoic Era around 540 million years ago, when land first became inhabitable due to the atmosphere finally having enough oxygen to block harmful radiation and provide for respiration. Oxygen in the atmosphere was the last great expansion of the biosphere, creating a boost to the amount of the planet available for life to exist. But exponential growth means this new space was used up in what appears on geological times scales as ‘instantly’.

Rule 3: Mass extinction events highlight how quickly vacancies fill and populations stabilise.

While there have been no new “garden of Eden events” to allow expansion of the biosphere in the past 500 million years, there have been dramatic mass extinction events, including the great dying and the lesser by perhaps more famous event of the impact that created the Chicxulub crater and which is believed to have triggered the extinction of non-avian dinosaurs. But after these events, the total biosphere recovers surprisingly quickly:

If there is a relationship between the distance from the impact and the recovery of marine productivity, we would expect recovery rates to be slowest in the crater itself. Here we present a record of foraminifera, calcareous nannoplankton, trace fossils and elemental abundance data from within the Chicxulub crater, dated to approximately the first 200 kyr of the Palaeocene. We show that life reappeared in the basin just years after the impact and a high-productivity ecosystem was established within 30 kyr, which indicates that proximity to the impact did not delay recovery and that there was therefore no impact-related environmental control on recovery.

Rapid recovery of life at ground zero of the end-Cretaceous mass extinction

There is no instant unoccupied suitable habitats following such mass extinctions, with the Earth undergoing the equivalent of rebuilding a new housing complex following fire. It takes time to rebuild and sometimes not every “room” or “house” becomes available for occupancy at the same time. This means the delay until new full ecosystems incorporate both the time for the environment to recover and the ecosystem to be rebuilt in addition to the time for organisms to populate the fresh environment.

Even though the changes to the planet redefined which species were now the “fittest” change the species that make up the biosphere, it takes a surprisingly short time for all “vacancies” to be filled, such that disruptions of this nature do not even show on the graph of the total biosphere from the paper by Franck et al.

There have been many less significant events that on a smaller scale also led to environments expanding or arising. These less significant events still create population growth opportunities when the environment recovers in the aftermath of the disaster or catastrophe that had damaged or even destroyed environments, but any vacancies are quickly filled. Examples of such natural disasters would include super volcanoes and impact events.

We have less spectacular but far more recent examples that we have been able to study more closely, like example of the humpback whales of the South Atlantic, which also illustrates how populations can quickly recover following setbacks creating temporary vacancies, but then return to population stability once numbers again reach their limit. While the whales were unable to increase reproduction sufficiently to stabilise population during the time of intense whaling by humans, the whale population was able to recover within just 70 years from a low of just 440 whales to historically normal 30,000 whale population level that had previously been maintained for thousands of years. This demonstrates clearly how when a ‘vacancy’ does arise, species can respond quicky to fill the vacancy.

The times an organism would experience a vacancy and respond with population growth are:

• When a species first evolves, first reaches a new suitable environment, or evolves new traits enabling out competing other species.
• Following a major catastrophe or disruption that reduced the population below previous levels.
• In the event of changes to the environment that alter constraints, such as weather or climate events, or disruption of predators or competitors for resources.

Note that as all similar environments are not necessarily connected, an organism reach a new suitable environment, long after it first existed on the planet.

When population increases are observed, either a for a new species, or species new to the environment, or following catastrophes or other major disruptions, the population growth of what is for that species, effectively a new vacancy, or an opportunity to evict the current occupants.

Vacancies can be short term, such as weather events, long term such as ice ages and long-term climate events, or the result of evolution as observed by Darwin, or evolution of technology such as stone tools, or farming.

Rule 4: No Vacancy ever requires more than 100 population doublings to become fully occupied.

Just 100 population doublings are enough for even the smallest species to carpet every cm² of our entire planet, which means 100 doublings is enough to for any new niche for life or “vacancy” to become fully occupied.

The principle is simple. Calculate the number that results from doubling something 100 times and then divide by the area of the Earth to see how many things would be per square metre of the Earth after 100 doublings.

How crowed does the Earth get after 100 doublings?

The ‘wheat and chessboard problem‘ illustrates how large numbers grow by repeated doubling, also known as exponential growth.

The wheat and chessboard problem considers doubling 63 times, in 63 steps from step 1 to step 64, doubling each step. One grain of wheat on the first square (2⁰=1) as the starting value, leads to 2 grains on the 2nd square (2¹=2), 4 on the 3rd (2²=4), 8 on the 4th (2³=8), all the way to 9,223,372,036,854,775,808 on the 64th and last square (2⁶³). So, a single living organism would result in 9,223,372,036,854,775,808 organisms after even 63 doublings.

Given the total land and ocean surface area of the Earth 510,064,472 km2, and each square kilometre is 1 million square meters, the 63 steps results in 18,082 organisms per square metre of the entire surface of the Earth, which for those who do not speak metric, is over 1,800 organisms per square foot.

So, starting from two humans, 62 doublings would result in 18,000 humans for every square metre of the Earth. Oceans included.

Not very comfortable for humans, but possible for something very small or perhaps microscopic. Yet even the smallest possible organism that could exist on the entire planet could not have even twice as many doublings, as allowing the 100 doubling steps would generate 2,485,275,234,437,872 organisms per square metre (over 25 quadrillion per square foot) or 2,485,275,234 organisms per square millimetre of the entire surface of the Earth.

So 100 doublings would overrun the earth, even with microscopic animals:

• 2.5 billion organisms for every square millimetre of the entire surface of the Earth, as a result of doubling 100 times.
  • …or in imperial
• 1.6 trillion (1.6×10¹²) organisms for every square inch of the entire surface of the Earth, oceans included, as a result of doubling 100 times.

For larger animals such as humans, or even ants, even filling the ‘chessboard’ is not required, as 63 doublings would mean over 8,000 individuals per square millimetre of the entire land and ocean surface.

Thus even 60 doublings would result in an impossible number of any organism large enough for humans to be able to see with the naked eye, and the 100 doublings would create an impossible number of even the smallest microorganisms that lives on the surface.

Rule 5: Almost every species, humans included, only needs at most 10,000 years for sufficient population doublings to fill any temporary vacancy.

Rule 1 shows that for every organism, 100 population doublings would result in sufficient numbers to carpet the entire planet with that species. In fact, for any species larger than an ant, around 60 doublings will be more than enough to reach their limit.

The next step is to calculation a species requires to double in population growth when given an environment with room for them to grow.

This question is not just simple mathematics and varies widely from species to species. But the challenge comes because most species normally have a stable population in the wild since otherwise the world would be overrun by that species. Most species are not currently in an environment allowing their population to grow. The stability comes from a combination of the species adjusting birth their rates or though predation when in constraining environments. This means usually the only way to observe their population growth rate when there is room to grow is to observe species in situations where their population is recovering following an event that reduced their population.

A search of “slowest reproducing animals” always seems to suggest pandas as being as slow at growing the population as almost any other species, both pandas and humans will now be considered as examples, because these are two species include one famous for slow population growth and we have data on unconstrained growth for both these species.

Pandas, famous for slow reproduction, have been shown to be able to increase population 17% in a decade. A 17% increase means 117 pandas for every 100 after 10 years. Since 1.17 to the power 4.5 is greater than 2, then pandas at that rate would double in population in 4.5 decades or 45 years, which is just a little faster than human population growth rate of the past century of one doubling every 50 years. Plus, pandas have also been around far more than 100,000 years.

The population growth rate for humans of the 20th century is well documented, but while it seems imaginable that it a traditional rate of growth, while it is a good example of very much unconstrained growth that is historically rare and thus well above historical average. If every couple has 5 children, which is below the historic average prior to the 20th century, and if 4 of those 5 children live to have their own children, then humans would double in population every generation, or a doubling approximately every 30 years. A more conservative figure of just one child above replacement rate surviving per couple would result in a doubling every 50 years.

But a but a doubling in population every 50 years would result in 60 doublings in just 3,000 years and producing more than 1,000 individuals for every square metre of the earth, which with animals the size of either pandas or homo sapiens, would more than completely cover the surface.

For perspective, humans continuing to double at this rate would have resulted in 100 doublings during the time of Ancient Egypt (over 5,000 years with almost 30 centuries as the leading civilization), which highlights the problems in maintaining that 20th century growth rate!

Rule 6: Many species limit population through birth-rates to avoid starvation.

At First, it can seem availability of resources alone controls population.

Although every organism on Earth has had far more than sufficient time for 100 doublings of population, every species reaches its maximum well before this theoretical 100 doublings.

So, either organisms just stop increasing in population, or something stops their population increasing.

At first it may seem logical that starvation is the constraints keeping populations from growing past the sustainable limit, but it turns out that waiting for starvation can be highly problematic.

Critics of human population levels always predict starvation from overpopulation, but looking at nature, where population stability is everywhere, widespread starvation is the exception rather than being normal, and most species seem have population limited by other factors. When mass starvation does occur, it is usually a sign of a specific temporary environmental problem.

The problem is population control by starvation for any species where the entire food chain cannot grow to full scale within one generation, could lead to those species consuming all their food leaving no food for the next generation and triggering total population collapse.

Overpopulation would damage the environment even before it results in starvation.

Consider a paddock with too many sheep. The sheep will eat all the grass until there is none left before they die. The overpopulation first results in environmental damage before the sheep starve. Yet grazing animals in nature don’t grow in population until the point when they destabilise the population of their food supply, somehow population is constrained before this point. Consider a mouse plague. There are so many mice they damage the environment, but far more mice are able to exist for a period time. This shows what happens when there is overpopulation, and the mouse population is not normally limited by food supply.

Some species are population restrained by a major resource like sunlight, which cannot be ‘overconsumed’. In contrast even a population of butterflies can reach a population level where their caterpillars consume all food in their environment, leaving no food for the next generation if the feed on plants with a longer lifespan than the butterfly.

If relying on starvation to control population can be catastrophic, then what stops population growth?

Life with populations in balanced is everywhere.

Consider our close relatives in the wild, chimpanzees, bonobos and even gorillas. To our knowledge, none of these animals was experiencing significant population growth prior to their recent population decline due to habit loss. What stopped their population expanding, given that, like all species, their birth rates can achieve population growth?

There seems no evidence that starvation is the mechanism of population control, as we do not see a percentage of chimpanzees, bonobos or gorillas starving, and nor do we see their populations growing to level where they damage the environment. If starvation was the mechanism of population control it would be everywhere throughout nature.

This is explored in full in ‘optimum population instinct‘, with the ‘whales‘ section providing an example of population reaching a plateau without any observed starvation.

The conclusion is clear, advanced animals do tune their rate of reproduction to match that which the environment can support. While bacteria in a petri dish may simply populate exponentially in total ignorance that they will exceed what is a viable population, more evolved species adjust their rate of reproduction in response to what is happening in the environment. Yes, this mechanism cannot handle all sudden environmental changes, which is why there are mice plagues, but it does adjust, which is why the plagues always end.

Every species can reproduce to quickly exceed environmental carrying capacity, but, instead of population growth to levels that will overtax and destroy the environment, almost all species can normally managed to control their own population. Without such a mechanism, overpopulation of species would result in environmental collapse, followed by mass starvation and they a population collapse before the cycle repeats. It may not be a coincidence than animals with many predators have many young, while apex predators do not.

All it takes is a simple nature walk to see that animals almost always exist in sustainable numbers, and their population is not controlled by a significant portion of their population starving, or having devastated their food supply through overpopulation.

This means every organism exists in sustainable numbers, without starvation acting as population control.

Rule 7: Species breaking through limits requires evolution of the species or environment.

While there is a gradual fall in the total biomass on the planet, that does not stop new species coming into existence and growing their population up until their limit. Mammals for example quickly took over many of the niches occupied by dinosaurs prior to the disruption caused by the Chicxulub impact event.

This period shows how quickly new species arise and fill new environmental niches following periods of change. We also have evidence of less dramatic change such as due to ice ages and other fluctuations.

What we do not see in nature is the balance changing without a cause. The cause can be the evolution of one species which results in more niches where that species is “fittest”, or due to changes in the environment.

But no species ever breaks through a previous population ceiling without change. Populations fluctuate with weather, but long-term change in population only follows long term environmental change or evolution of the species.

Well, perhaps except with humans?

Humans: Exempt from the rules or still evolving?

Human Population Growth: still growing to our limit, or moving the limit?

It could appear that human population is still growing long after we should have reached our constraints.

Have humans managed to break these rules? The theory says we humans should have reached a stable population close to 300,000 years ago, at which point population growth would stop.

Yet we are not breaking the rules or below our limit despite that human population growth still continues and was doubling almost every generation as recently as between in 1965-1972 and doubling every 50 years for most the 20th century.

The reality is humans did reach our limit hundreds of thousands of years ago and have been existing at our limit for almost the entire time since. However, we do manage to keep raising our limit! While it initially looks like humans have never reached their limit, looking closer shows this does not fit the data, and our population has almost always been constraint at our limit, but we keep moving our limit.

The theory is that for species to achieve an increased limit, the species must evolve and thus become the ‘fittest’ for more niches within existing or new environments.

The further we look back at the history of the growth of the population of humans, the lower the rate of population growth that is evident. From 70,000 BCE to 10,000 BCE the population grew at most by 2,500x (3,000 to 4 million) which was 60,000 years of growth rate < 0.012% pa, then followed 12,000 years with a growth rate 0.05% and growth accelerating to peak at over 2% per annum from 1965 to 1972.

Given the human population has been proven to be able to grow at 2% per annum, why was actual growth so slow for so long, and why did the rate of growth increase over time!

The answer is that human population growth has almost always been constrained by being at our limit, but we have been able to increase our limit at an accelerating rate throughout history. As the rate of technological development increases, so does the limit on human population.

To recap, Homo Sapiens have existed for at least 300,000 years, which is sufficient for 6,000 doublings of population, yet if there were only 2 people 300,000 years ago, the population growth to 8 people billion now represents just 32 doublings in over 300,000 years. Only 32 doublings over 300,000 years is an average population doubling time of over once every 9,000 years, and far, far slower growth the two doublings within the 20th century!

Looking back at the average growth rate, to take 9,000 years to double the population requires an annual growth rate of around 0.008%. This is a rate very close perfect population stability, yet we have seen from recent times, that there can be periods of rapid population growth. It seems likely that growth is mostly effectively zero, with occasional bursts of real growth, and we have just witnessed one of these bursts.

Even excluding the recent population explosion, and just looking at the long-term trend, that fact that human population is growing 300,000 years after humans first appeared suggests:

• Recent environmental change has made humans increasingly compettive as a species.
  • and/or
• Humans have evolved to become more competitive as a species.

The key point is there has been evolution. Humanity has evolved through knowledge and technology, without us evolving physically as individuals. Each step of evolution allows us to out compete more and more of the rest of nature.

Bursts of population growth through accessorised evolution.

Instead of a recent series of steps of biological evolution, humans have experienced accessorised evolution, which allows humans to continue to evolve even without significant biological advances.

A list of some notable steps includes:

• A population expansion during the Palaeolithic age arounds 60-80,000 years ago, through “the emergence of newer, more advanced hunting technologies”, following further developments of language.
• Another growth phase at the start of the Neolithic age that from around 5,000BCE 7,000 years ago to 200BCE as farming spread to global adoption (see graph).
• The population explosion from around 1650 with the industrial age and the reductions in child mortality.

Note that even during periods of population stability, from 10,000BCE to 5,000BCE and from 200 BCE to 1600AD, there was still some population growth as humans managed to colonise more locations.

Does total biomass set the absolute limit to human?

Continuing to replace other species has a limit. Eventually there would be only one species, or at least only one species that occupies our niche in the environment.

As of the year 2000, most other vertebrates that are not farmed by humans are already seeing population decline, if not threatened with extinction as a result of habitat loss. The impact of two population doubling in the 20th century was severe, but as every doubling requires adding twice the number of people, most analysists see even one more doubling as not only destructive for other species, but also a threat to the existence of humans.

But still, there is the quest to go further. Many promote that by moving to a vegan diet and reducing the global population of grazing animals, we could further increase the human population. While a vegan, or even also vegetable free diet, may be the future, it does worry me that current such a push is used as a distraction from methane increases from natural gas mining, and as a path to further human population increase at the expense of other species.

The further our population grows, the smaller percentage increase the results from even 1 extra billion humans, and the smaller the population of other species, the greater the impact and the more extinctions that result from adding 1 extra billion humans. Inevitably the gains get more marginal and more damaging.

Humans are not exempt from the rules.

The conclusion is clear. We are not exempt from the rules, and even without climate change causing CO₂ emissions and our pollution, the total biomass of not just humans but our food supplies, pets and gardens, and environment reducing urban landscapes, mean that the total biomass of the rest of the biosphere must contract. Lower numbers of in total of all other species is the inevitable consequence of increased human population size.

As the first species to progress to accessorised evolution, perhaps it is logical that result is to be threatened by our own evolutionary success in being able to be the ultimate “fittest” species.

Garden of Eden or humans imagining vacancies? Delusions of being gifted an empty planet.

My use of the term “garden of Eden” is neither intended to endorse nor critic religion or religious texts, and I do not believe any findings here neither contradict nor confirm the contents religious texts, which are open to interpretation with regard timeframes and specifics. What I questioned was my own initial interpretations of concepts expressed in the religious texts.

There is the biblical line: “go forth and multiply”. I had interpreted this as humans being given an empty, and effectively infinite planet, ready to be colonised, however the reality is that while the very first species of life was gifted an empty planet, the planet became fully populated long before humans appeared.

I personally grew up with the assumption that we live on a planet that is effectively partially vacant, and humans and other species increased in population as they “grew into” this still partly vacant planet, and growth of population of all living things was part of nature.

Yet long before the first human walked the Earth, there was already ‘no vacancy’. For humanity to even exist, we had to outcompete and displace other living things. But is it our mission to replace every living thing possible until it is just us and the food we farm?

Ignorant Displacement: Humans tend to treat the displaced as invisible.

Our current society has evolved the technology to be ‘the fittest’ in almost any niches, that we can maintain a higher human population than ever before. We can also, per unit land, maintain a higher population of crops and livestock to feed us than ever before.

The downside is a history of not even seeing organisms displaced population increases are introduced.

In fact, historically even other humans displaced by humans have been repeatedly overlooked and/or underestimated. Accessorised evolution results in one society being more “evolved” than another as the accessories available leapfrog each other are shared. A huge problem is that societies have repeated the mistake of seeing advances through accessories, and assuming it is the humans rather than the accessories that have evolved, leading to the assumption humans without the latest accessories, particularly those the functions as weapons, are inferior humans, rather than simply biologically equal humans equipped with less advanced accessories.

Despite that experts now believe between 10 and 16 million people lived above the Rio Grande in North America prior to Europeans arriving:

Few contemporaries agreed with Catlin’s lofty estimate [16 million] of the Indian population before contact with the white man. “Twaddle about imaginary millions,” scoffed one Smithsonian expert, reflecting the prevailing view that Indians were too incompetent to have ever reached large numbers. Alexis de Tocqueville’s cheery assertion that America before Columbus was an “empty continent… awaiting its inhabitants” was endorsed by no less than the U.S. Census Bureau, which in 1894 warned against accepting Indian “legends” as facts. “Investigation shows,” the bureau said, “that the aboriginal population within the present United States at the beginning of the Columbian period could not have exceeded much over 500,000.”

How Many People Were Here Before Columbus?

Even if there were only 500,000 people before Columbus, the nature of exponential population growth tell us, that as people had been in North America for around 30,000 years, the continent would have been populated up to the level of environmental constraints. Any land mass with even 3,000 years occupation will reach the maximum population possible for that society. Yet to people from Europe, America was ‘an empty continent’. Not only did the new arrivals not understand or see that the continent would be fully populated with the current population, they even failed to recognise the size of that population.

The new arrivals failed to recognise that this ‘new world’ continent was fully populated, and that their arrival must displace those living there already. In the 30,000 years since people first arrived in America, culture in free trading European/Middle Eastern/Asian society had managed to evolve 1,000 or perhaps even 2,000 years further in terms of dominating more of the environment, increasing population density and as a result displacing other organisms. The population of many species would need to decline in order to accommodate the influence of European/Middle Eastern/Asian evolution of society.

The spread to new territory and the impact on life before that spread highlights the changes humans had over time to the environment of Europe/Middle East/Asia, displacing other species as advances made humans the most ‘fit’ for ever more niches within the environment.

Delusions Shattered and Questions Raised.

Calculating these numbers, has shattered some illusions I had previously held, but has also raised some interesting questions still to be answered. Previously I had not thought through enough to realise that every increase in the population of humans and their chosen foods, inherently means a reduction in other populations. I had thought habitat destruction and decline of natural diversity as mostly a consequence of poor management, rather than a mix of poor management and a natural unavoidable consequence of population growth.

The problem seems to be that I looked a the world through a filter which does not recognise what is different and being displaced, in the same way Europeans in the ‘New World’ did not recognise what they were displacing.

• Shattered Delusions:
  • Both North America and Australia were fully populated prior to the arrival of Europeans.
    • I had previously thought, as apparently did the European arrivals, that these continents were only sparsely populated prior to Europeans arriving. Realistically, any land mass continuous land mass occupied by humans for as long 3,000 years will be fully populated to the extent possible by that human society, as were North America and Australia.
  • I had thought population levels have been growing because the Earth had never been populated to capacity.
    • The reality is, Earth has been populated to capacity for the hundreds of thousands of years. Population increases result from changes to society that allow humans and their food to displace other species of life on Earth.
    • The question that arises is, has the recent unprecedented population explosion stayed within the bounds of the population now supported by our changed society, or has the change to infant mortality created an ‘overshoot’ resulting in overpopulation and the environmental damage that follows.
• The questions raised:
  • As already covered, has the population explosion resulted in overshoot? Yes.
  • What does natural population constraint look like? This was explored in Optimum Population.

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Updates.

• 2023 November 19: 2nd Edition with clarified rules and “garden of Eden events” explained.
• 2022 April 4: fix typos.