'The fate of every successful species is to wipe itself out'

I read this essay by Charles C. Mann a little while ago, and I’ve been mulling it over since then. It’s very long, and I highly recommend reading the whole thing, but here are a couple of excerpts that lay out the problem:

Mann goes on argue that it’s possible for humans to avoid that fate, but I didn’t find his arguments to be very convincing. I’m interested in hearing what you guys think about this question. Are humans doomed to destroy ourselves?

People have been discussing this for a while. Malthus did though Malthus didn’t really predict a catastrophe, many others have using similar thought processes.

Like Paul Ehrlich who said the following in the first edtion of The Population Bomb:

Obviously, Ehrlich was a little off in his prediction. Which, by the way, he keeps telling everyone either wasn’t really a prediction or just hasn’t happened yet.

So, I tend to take these kinds of things with a huge grain of salt that happens to be labeled "Us evil humans are going to destroy the world! We Suck!’.

People keep predicting the end of the world, or a major catastrophe. We do end up with some catastrophes, though they tend to be blowing each other up and shooting each other types of catastrophes.


The argument here isn’t that humans are evil or that we suck. It’s that all living creatures, humans included, will grow out of control and overwhelm their environment if there isn’t an outside force to constrain them.

Human population is not currently growing exponentially, it is growing but the rate of increase is decreasing. If the decrease in the rate of increase continues, then the human population will peak and slowly start to decrease in the next 50 years.

Exponential growth means doubling every X years. Current projections are that the current world population will not even double once.

Plus, you know, rabbits in Australia didn’t wipe themselves out. The population crashed after the introduction of various rabbit viruses, but the population of rabbits is still in the hundreds of millions.

Humans appear to buck this trend. In many First-World countries, where there is no disease and/or predators to control the population of humans, the human birthrate is nevertheless below the replacement rate.

[Yes, amusing user name/post combo. So sue me. :smiley: ]

Humans have two advantages over protozoans (there may be more, but just in this context I’ll talk about two):

  1. We are self-aware, and aware of possible future consequences. This is what the author was talking about in the first quote. Unlike other species, we can change our behavior to limit the damage - not just population growth, but wearing out of resources and the environment.

  2. Humans don’t have to wait for evolution to make beneficial changes. We can invent technologies and also (still speculative) we can probably make changes in our own biology to minimize or mitigate the damage generated by our existence.

For those reasons, I always regard predictions of doom arising from human existence as doubtful. Call me Micawber, bit it seems like something always turns up. People are damned clever, after all.

n.b. that doesn’t mean that nothing bad can ever happen or that we shouldn’t pay attention to warning signs. That’s just the point. We can pay attention to warning signs, and can figure out how to avoid the catastrophe.

Or we change the environment to suit our needs. Which is what humans have been doing since the first one planted a grain of wheat.

In the most abstract sense, human being are comprised of carbon, water and energy. This planet has more than enough of the first two, and as for the third, the sun isn’t planned to go out for a billion years or so. With sufficiently advanced technology the earth can support trillions of people.

Nothing speculative about it. Condoms, birth control pills, vasectomies, etc. are ways we are changing our biology to limit our effect on the environment.

There are certainly challenges that could cause serious hardships, but overpopulation is no longer the serious threat it was considered. Resource limits still exist, but they are usually not “hard” limits. Like petroleum, for example, will probably never run out completely, it will just become so expensive to remove that it will force movement to other sources that are either too expensive right now, or otherwise not worth developing.
This is also not to say that local shortages and catastrophes will not happen. And something could cause a million people to die is still a huge tragedy even if it that is only 0.015% of the total population.

Bottom line for me, reduce poverty, increase education and freedom (especially for women), and between lower birthrates and longer average lives, population will stabilize at more sustainable level in the next century.

It’s a fairly interesting essay, but it seems at least a couple of important factors are being ignored there.

Maybe I’m wrong, but I have the impression that major extinctions of ‘higher’ species (that is, more complex than microorganisms) have been due to external factors: not just drastic climate changes related to volcanism, asteroid strikes, ice ages and the like, which cut across many species, but individual species being squeezed out of their ecological niche by species more readily adapted to ambient conditions, or perhaps becoming food for those better-adapted species. This is a somewhat different mechanism that what the essayist seems to be discussing.

Consider: trilobites, as a group, were a significant part of the Earth’s fauna for hundreds of millions of years; dinosaurs, again as a group, for tens of millions. In neither case does it appear the species that make up these groups died out because they “reached the edge of the petri dish”, metaphorically speaking; it was more like someone came along and smashed the dish.

While I can certainly see an argument for future waves of population crashes in humans due to such factors as environmental pollution and/or dependence on too few cultivated foods, I dont think that those on their own would wipe out the entire population of humans. I think we as a species are much more likely to disappear in some sudden world-altering climatic disaster.

A third important reason: humans have civilization, which makes us much more powerful as a species, while itself being relatively fragile. Continual damage to the environment will make global civilization collapse much, much sooner than it will drive humans as a species to extinction. And the collapse of modern civilization would largely limit how much more damage we could do to the environment, preventing it from degrading to the point where it threatens the continuation of the species.

I haven’t read the entire article but it looks interesting.

As others have said, humans tend to reduce their offspring to reproductive rates or lower when income hits 5k or so per capita. Here is a curve comparing per capita GDP with number of kids per woman. It is pretty much a vertical drop until about 8k and the vast majority of nations above that have fewer than 2.1 kids per woman.

If anything, a lot of upper income and middle income nations are starting to worry about depopulation because people stop having enough kids to replace the living people. Japan has 130 million people, worst case scenario with current repopulation rates they will be down to about 50-60 million by 2100.

I personally wonder, to what degree, that is due to the fact that life really isn’t that great. In the past people took it as a fact that life was miserable, but nowadays we have enough technology to make us comfortable enough to realize we still aren’t happy and a pretty prone to misery. But I assume the bigger factor is just economics because people can’t afford tons of kids.

What happens 100+ years from now when we are in a post scarcity economy, advances in neuroscience has made life unfathomably blissful and we have immortality? No idea. But I doubt we run out of food anytime soon. A lot of agriculture on this planet is either used inefficiently or grown inefficiently.

The examples mentioned in the OP aren’t really “successful” species. They are species that have been placed in an artificial environment (e.g., a petri dish); or in an environment they are not native to, and where the natural checks and balances (e.g., diseases and predators) that control population levels have been removed. Personally, I think a better definition of “successful species” is one that has established an equilibrium with its environment, and has a stable population somewhere near its carrying capacity.

There are species that use a “boom and bust” strategy – that, for example, will move into an area devastated by a forest fire, and will then fade out as the forest regrows and stabilizes. I think it’s fair to say that humans have at times been in an exponential growth phase and have depleted resources. There’s good evidence that the human population expansion into North America, for example, had a lot to do with the extinction of mammoths. And with medical and agricultural advances of recent decades resulting in a reduction in our death rate, our population has been growing at a rate which is not sustainable indefinitely. We’ll need to adjust our population growth to an eventual new equilibrium; as noted by other posters, that’s already happening. There’s no reason to think that extinction is the only end result.

The idea that “all successful species” are destined to exhaust their resources, rather than establish an equilibrium population with their environment, doesn’t really make any sense from an ecological perspective.

Yeah but with trillions of mouths to feed, soylent green would be a large part of our diet.

No, we aren’t necessarily doomed to destroy ourselves. And the whole premise of the thread is flawed to be honest. Not all successful species wipe themselves out due to over population or over use of resources. Sharks, for instance, have been around for hundreds of millions of years and are still going strong, and aren’t in danger of wiping themselves out. Various ‘dinosaur’ species also lasted for long periods of time, and it wasn’t over population that wiped a good number of them out, it was an external disaster. Same goes with various other periods in history…most of the large scale extinction events were external, not due to a species wiping itself out. In fact, I can’t think of a single instance where it was a species itself that did the deed, it’s usually due to adaptive specialization and then radically changing conditions that does in a species (a large rock falling from the sky, volcanic activity, climate change, etc).

Arthur C. Clarke speculated that all technological civilizations have limited lifespans because once they discover nuclear energy, their days are numbered. Maybe he was right. Or maybe it’s one of the other reasons discussed here. There is certainly some reason that SETI isn’t hearing anything out there, despite the heavy statistical odds for Goldilocks planets and the formation of life! Maybe it’s because dead civilizations tend to be pretty quiet.

Or the signals become distorted background noise between the stars, or civilizations start using satellite based broadcasting so all the signals are directed and absorbed by the planet, or they stop broadcasting altogether and everyone just uses global wifi, etc.

I think the human species is largely aggressive and cannibalistic, although I’m not sure this trait can by itself cause our species to wipe itself out. Moreover, I doubt that the article is based on comprehensive biological facts. An impressive range of bacteria species have been successful for millions of years and they don’t show the slightest sign of wiping themselves out. Different species of grass may compete for the same environment, but the successful one doesn’t wipe itself out. The cattle or rabbits feeding on the grass don’t wipe themselves out either. For example, when the number of rabbits exceeds the carrying capacity of the area, the rabbits that can’t find unoccupied territory become suicidal. Eagles limit the number of their chicks and those eagles that can’t find unoccupied niches are pushed to places where they starve or can’t breed, but the species as a whole is not affected.

Humans are endowed with reason, which may help our species prevent its cannibalistic tendencies because we do have the ability to wipe ourselves out in many ways. Will we use our intelligence wisely? I have no idea.

The early signs are when we start fucking each other over for a goddamn percentage.

I agree. The article in the OP reminds me of one of those guilt-tripping “lessons” that kids get taught in school. (This is what happens if you don’t clean up after yourself!)

Exactly. My initial reply to the OP was going to be “Define success,” and you have defined it better than the people in the article. A species that reproduces until it has nothing left to eat is hardly successful. It’s just temporarily productive, like a corporation that is considered successful because it paid a dividend this past quarter while not having a plan for next quarter. And it is the sort of thinking that I’m not surprised people who study insects and microbes can fall into. However, humans are not automatons.

Plus, Lynn Margulis was a Pure D nut. Did good work in her youth, but crazier than a shithouse rat towards the end.