Although the scale of the contraction that lies ahead for the human race is unprecedented, our ancestors have passed through many critical periods where the effective population size decreased dramatically.
On many previous occasions the total population size shrank, while in others a small group with some competitive innovation replaced the previous population. Either way the end result was the same- a new form of humanity founded by a relatively small pool of ancestors. This process has repeated many times to make modern humans one of the most inbred animals on the planet.
Genetic analysis has hinted of a strong bottleneck between the primitive Australopithecines and Homo erectus, their much more successful descendant. Stronger evidence is available for the more recent transition to Homo sapiens. It appears the global hominid population shrank from 2.5 million to under 10 000 individuals, possibly in response to the catastrophic volcanic eruption of Mt Toba. Other large mammal species display evidence of a genetic bottleneck around the same time. Some researchers dispute this model of the emergence of Homo sapiens, instead favoring a prolonged multiregional evolution in Africa. The tribulations of this period seem to have pressured early modern humans to become more cooperative with others, increasing maximum social group size and allowing connections between neighbouring tribes to trade.
Clear founding bottlenecks are evident in the genetics of groups that left Africa, and again when they crossed into the Americas (though more recent evidence suggests multiple distinct founding groups). Many modern groups show evidence of founder effects. Ashkenazi jews appear to have been reduced to a few thousand individuals a millennium ago. Many castes in India appear to have been founded by small groups and practiced strict intermarriage for similar timespans.
In more recent history a few situations stand out as bottlenecks. Population estimates are fuzzy for the period of the Bronze Age collapse, but evidence shows cereal cultivation was abandoned over many regions in Europe in favor of pastoralism. The regional economy peaked as a series of kingdoms with dense urban centres, who traded the tin and copper to make superior bronze weapons and tools. These in turn allowed more intensive agriculture and higher population densities. Experts disagree on the trigger for the collapse, but it resulted in abandonment of most of the cities around the Mediterranean and a loss of literacy for many generations.
The Black Death represents the second most dramatic disease driven population decline in recent history, with 20-50% of the population of Europe lost over a generation. Analysis of populations before and after show certain susceptible genotypes were driven close to extinction. This event had major cultural and economic consequences, weakening the authority of the church enough to allow the birth of rationalism, and disrupting the balance of power between the wealthy and the poor. It also triggered improvements in labor-saving mechanical technologies in the form of wind and waterwheels, which built a foundation for the industrial revolution. It also freed up metalworkers from producing chain mail, allowing them to instead produce papermaking moulds which crashed the price of paper (a fairly new invention spread from the east like the plague itself) which in turn made the printing press economically feasible.
The most dramatic disease driven bottleneck happened in the Americas following introduction of multiple epidemic pathogens. Estimates vary wildly, but Mexico is believed to have declined from 22 million to 1 million in a period of years. The biological consequences of selecting out a small percentage of resistant individuals will probably always be unknown, but the cultural and economic consequences were devastating. Given recent increases in global population a contraction of a similar scale in the future is not implausible, though it will likely take much longer.
Notable bottlenecks of the past happened for a few different reasons. Sometimes the carrying capacity of the land was dramatically decreased, due to a catastrophe or climate change, or the loss of a key technology. Other times the carrying capacity remained unchanged, but the previous population was reduced through disease. Sometimes a small divergent population used a unique advantage to outcompete older, established populations. Often a combination of these factors work together- for example the horse riding Yamnaya warriors who replaced the early farming men of Europe had a much easier job due to the spread of an early wave of the Black Death (which they probably spread and were partially resistant to).
The challenges ahead for humanity also represent a combination of possible stressors. Our carrying capacity has been artificially inflated through the use of concentrated, non-renewable resources like oil and coal, which allowed us to tap into previously inaccessible resources of metals and chemical fertilisers, then cheaply transport the products of industry everywhere across the planet.
Our tightly woven trade network and the resulting intensification of population density most resembles the scenario that led to the Bronze Age collapse. The disintegration of industrial power might trigger cascading mass migration (the primary force which destroyed the cities of antiquity). The unprecedented urbanisation of populations around the world could be regarded as the first stage in this process. Around the world, regions where people retained some of their pre-industrial culture sit alongside the most highly urbanised: Europe and the middle east beside Africa, Central America beside North America, Papua New Guinea beside Australia. One thing that is very different today is that the landscape is so degraded that it is unable to support nomadic populations (the Mongol’s horses would starve before they passed through the suburban fringe of modern cities), though this must be balanced against the persistence of high speed/long distance transportation methods from what remains of our industrial age.
More probable, given our ailing systems of health, nutrition and sanitation, is the emergence of a novel epidemic pathogen, or more likely the reemergence of several older ones that people find it hard to get excited about. Antibiotic production and distribution chains were stretched across the globe for maximum efficiency, and shortages of these key drugs are becoming common even in rich nations. Slow moving epidemics like multidrug resistant tuberculosis don’t grab the attention of the media.
This all sounds pretty dreadful to the average person. However a study of the history of bottlenecks reveals that they bring an opportunity for transformation that isn’t possible during normal times.
One feature of bottlenecks is the loss of advanced technology. A close study of archeology reveals all sorts of artefacts that even high industrial technology of today would have difficulty reproducing. The high technology of a peak can drive simpler technologies to extinction, meaning they do not automatically reappear after the collapse. I predict there is a decent chance that iron smelting will become a lost technology in the future. Currently only a small number of dedicated enthusiasts have mastered the primitive techniques for turning hand mined iron ore and charcoal into workable iron. They are mostly scattered and elderly people. During the downslope of industrial civilisation there will be an abundance of scrap iron that can be reworked to meet basic needs, a much simpler process than creating new iron from ore. By the time people run out of iron for recycling the few people who understood the intricacies of low tech ore smelting will be long gone. This would be an advantage to humanity in the long run, restoring a more sustainable balance between people and trees. The civilisations of the Americas achieved superior civic organisation than anything comparable in Europe or Asia without the need for iron.
The cultural memory of mass/long distance communication is likely to survive. It is plausible that humanity will rediscover or maintain radio but will probably never again make integrated circuits or satellites. Memory of the core principles of biology will probably be retained so that we can engage in selective breeding (including of humans) but will never again be able to sequence or manipulate genomes directly.
Some general trends are seen in the history of human bottlenecks. The general trend has been increasing intelligence balanced by decreasing physical robustness. The groups with the best capacity for interpersonal cooperation and coordination seem to win out in the end (which favors rice farming communities of south east Asia).
Ossified forms of culture tend to be swept away and eventually replaced. I hope the abomination that we call written English will finally be put to the flame and a better language takes its place. Mass migrations tend to blend languages, so hopefully the best parts of several languages are hybridised and selected.
The ideas we have gained during the age of industrialisation and rationalism that survive the coming contraction will need to be repackaged in a form that is simple, compelling, evident through ordinary experience and most importantly, useful. What these ideas might be, and how to craft them into a durable packages (such as fables) is a puzzle I am currently contemplating.
The age of industrialisation will have other enduring legacies. One important way the world has changed is the movement of diverse people’s over vast distances, creating new, hybrid populations. Traditionally these have been the source of cultural innovation. The most notable examples are found in South Africa, the Phillipines and south/central America. The diaspora of south east Asian merchants into every corner of the world will also likely have lasting consequences. Likewise crops, livestock and weeds have been scattered across the planet, fundamentally changing ecosystems and potential post-industrial agriculture.
Finally, there is a possibility that humanity will modify itself through industrial style genetic engineering during the desperate years ahead. We have already attempted to produce HIV resistant babies (though this trait is relatively common already among people). I can think of a handful of simple but transformative changes that might be achieved with our limited tools and understanding. I explore a few of these ideas in my recently released science fiction novellas.
In these stories I explored the possible long term consequences of the end of industrialisation in a series of novellas, Our Vitreous Womb, recently released on Amazon. The inner workings of a new society built on pure biotechnology are experienced through the eyes of four diverse individuals in interconnected stories. Currently I’m chasing three more reviews on Amazon to apply to a science fiction promoting list, so if you can read and review I would be most grateful.
Reviews so far have been very encouraging. Here are some of my favourite excerpts:
“The story was fast paced and gripping. It reminded me of Atwood’s ORYX AND CRAKE.”
“Also a shout-out to the prose. It’s very strong. Especially the first chapter was magical to read.”
“It’s rare to find such a combination of storytelling and well-imagined speculative science fiction, and when you add in concise, precise prose, it creates something truly outstanding.”
“This is one of those books where it feels as though the author has actually visited their world. The details are sharp and clear, and backed with logical, consistent worldbuilding.”
So now for the conclusion to today’s post. This is meant to be the part where I put a positive, hopeful spin on everything established so far.
How about this?
Everyone alive today is going to die.
That is an inevitable and unremarkable fact, as true today as it was at any time in history, and likely to be true for the millions of years of life left on this planet.
What matters today is which new lives will be created and nurtured through the coming contraction, and how they will be trained and educated to carry a more modest version of humanity into the vast future.
There was never anything particularly desirable about cramming many billions of people on the planet. Nobody set out to get where we are today. It was an accidental consequence of well-intentioned increments in agriculture and technology.
Once this time is over, its passing will come as a relief, not just for humanity but for the entire planet.
This tribulation will change us, in ways we cannot fully imagine, just as Homo erectus could not have imagined the wonders of ancient Rome.
Our time as a species in this tower of metal and glass is nearly over.
Your job is to carefully select a handful of useful and compact items and ideas to carry with you, to pass forward on the next phase of our long journey into the future.