Are humans on the verge of extinction? Opinion piece

[russ_watters]

Post 24.

You didn't write post #24. I think it does a pretty good job of framing the issue. I find your posts vague yet suggestive (not unlike the article), which makes your points difficult for me to pin down.

 

[Jarvis323]

You didn't write post #24. I think it does a pretty good job of framing the issue. I find your posts vague yet suggestive (not unlike the article), which makes your points difficult for me to pin down.

Or maybe you have a bias.

 

[russ_watters]

There is a doomsday clock. I assume that it is based on at least a few facts, i.e. real threats. E.g. what's currently going on at the Ukrainian-Russian border has the potential of an uncontrolled conflict.

Sure, I guess, but the facts don't lend to a predictive model (much less consistent parameters) for setting the clock. It's entirely a tea-leaves style interpretation.

I also think that there can be given a probability of certain cosmic events. GRB, PMO, or asteroids as big as Texas could be candidates of a total loss. If astronomers can tell how likely it is that Apophis will hit us, then they probably have estimates of the other events, too. Still better than speculating about a pandemic that affects all of us if even the plague couldn't at times when we neither had antibiotics nor reasonable hygiene.

Yes, that's true. Such things as asteroid impact frequency and magnitude are measured/modeled. Here's a laymans' article that says one of the size that killed the dinosaurs hits every 50-60 million years (historically):
https://interestingengineering.com/...of-a-huge-civilization-ending-asteroid-impact

 

[russ_watters]

Or maybe you have a bias.

I do indeed have a bias, in favor of specificity.

 

[PeroK]

Note the author calls a million years or so rapid.

No one knows whether there will be human beings on Earth a million years from now. A million years in terms of human cultural and technological evolution is an unimaginable time. No one can predict what is going to happen over that timescale.

That's another reason the article is so poor. On the one hand he talks about these huge timescales and on the other he's taking about "Habitat degradation, low genetic variation and declining fertility", which are short-term issues.

You can see immediately that habitat degradation is more significant for the other life that inhabits this planet, because they cannot escape the consequences; whereas, we can adapt.

Low genetic variation without modern medicine might be disastrous, but we have medicines and are no longer dependent solely on our natural defences. Not to mention the recent advances in decoding our genetic structure and all the possibilities that opens up.

Even if declining fertitility became a serious issue, who would doubt that we would develop the capability to continue to reproduce?

My point is that the article's arguments are paper-thin to the point of being nonsensical.

 

[InkTide]

I feel like any fears of low genetic variation leading to terrible outcomes for humanity are fundamentally at odds with the fact that we, as a species, have essentially erased all but the cultural and social barriers to gene transfer - we've made geographic distribution nearly irrelevant to accessing the full breadth of diversity in the human genome. That's why it's "samey"; it's mixed globally as opposed to regionally. If the "samey"-ness was an existential threat to our species there wouldn't be nearly 8 billion of us, each of whom represents new opportunities to add to that diversity through mutation. Because that's essentially what sexual reproduction evolved to do anyway.

Ironically, modern medicine raising the threshold genetic disease has to meet to remove someone from the gene pool should increase genetic diversity by increasing the number of viable mutations. Granted, that can be harmful, but it can also confer unexpected advantages (see: sickle cell anemia in the context of a hypothetical malaria pandemic) - bottom line, genetic diversity in the human population is not in any reasonable danger absent an existential threat to humanity (that isn't genetic diversity) collapsing the population.

I also find the fertility argument very poorly reasoned, especially the conjecture that being around other people is stressing out the sperm. We are a deeply social species, isolation is far more stressful than company, unless you've been made a pariah. Maybe culturally we do that too often, making a production of shame and ridicule for entertainment (because it's basically counterproductive to rehabilitation/persuasion) but I still don't think there's any merit to blaming it for lazy sperm.

There's also the whole issue of extrapolating to absurdities the current population trends, either with exponential unstoppable growth and looming extinction as it rises or looming collapse and extinction if it starts to dip. Population follows a logistics function for simple thermodynamic reasons: it takes more calories to make a child than it does to stay alive without making a child. Humans in particular have a staggering amount of caloric requirement for postnatal development because we are basically born incomplete - if we stayed in the womb any longer our massive heads would be too big to fit through the pelvis, which itself is smaller to accommodate our bizarre bipedal gait. Over time, provided no massive changes in the carrying capacity occurs (i.e. from an existential threat that isn't a misunderstanding of the basics of population dynamics), it will stabilize to around the carrying capacity. Decades ago we were in the part of the logistics function that looked exponential because we hadn't hit significant limiting factors yet, and now the primary limiting factor is simply: people will have families and expand population generally when they consider it feasible and comfortable to do so. People aren't statistical blips incapable of reacting to changes. We can evolve not just as a species, but via intelligently designed (heh - by us, of course) changes to behavior at the individual level.

 

[Klystron]

The original article appears hobbled by anthropocentrism.

Working definition anthropocentric:

1. regarding the human species as central.
2. viewing and interpreting everything in terms of human experience and values.

While difficult to avoid while discussing humans, a science paper should acknowledge and attempt to mitigate bias. Altruistic social movements such as zero population growth (ZPG), arguably successful given data in this article, recognized human overpopulation as a primary social problem ostensibly causing or exacerbating related existential problems such as climate change, pollution and vital resource depletion.

An inherent shortcoming of ZPG programs becomes apparent even within a single lifetime: Who heeds the call to limit reproduction? Who ignores science to reproduce without limits?

One hopes that human colonization of space leads to social organization based on reality.

 

[Hornbein]

"This idiot race that believes they have free will." -- Albert Einstein commenting on German involvement in World War One. He wrote that the Germans entered the war in order to make money, as their fathers and grandfathers had done.

 

[Evo]

I don't understand where this comes from:

Birth rates seem to be higher than death rates worldwide. Plus, how is halving the population in a country considered "underpopulation". Was the world "underpopulated" 50 years ago?

Is a population decrease necessarily means an extinction? 4000 years ago, they were only a few dozen million of individuals on Earth, and nobody talks about that period as being on the verge of extinction, quite the opposite.

Finally, if a number goes down, how do we know it won't stabilize or go up again?

Trying to predict human extinction is a pointless exercise at best.

Around 70,000 years ago, humanity's global population dropped down to only a few thousand individuals, and it had major effects on our species. One theory claims that a massive supervolcano in Indonesia erupted, blackening the sky with ash, plunging Earth into an ice age, and killing off all but the hardiest humans.

https://www.businessinsider.com/genetic-bottleneck-almost-killed-humans-2016-3

 

[HAYAO]

Before we even get to the topic, I question the author about how the numbers are calculated. We have two different method to calculate how often we have more births. One is "birth rate", which is calculated as number of births/1000 people/year. There is also the "total fertility rate", which is calculated based on the number of children women will have in their reproductive lifetime. I do not like how the author uses birth rate, since birth rate can decrease by population aging (old women have slim chance of fertility). Although the latter calculation has its own flaws (e.g. it has its own assumptions), I would rather have the author use the total fertility rate. That's a bit nitpicky point, but I'd rather use numbers that better describe a situation.

Anyhow, I'm going to speculate as much as the article in the OP did, but I don't think the author spends enough time understanding at what circumstances do the total fertility rate (TFR) drops. Almost all developed nations experience low TFR while developing nations experience the opposite. So that's what we would need to understand first. Decline of TFR is determined (although correlatively and not casually) by how developed the nation is. The social psychology behind this is still unknown, but we do have a way to dig down further on this.

Since it takes a man and a women to reproduce, to maintain a population, at least 2 children must be made in lifetime. When we look at developed nation that experience TFR below 2, it's not that married couples don't make enough children. In most countries on average, married couples maintain somewhere around average TFR of 2 over the span of 40 years at least. So if you are going to talk about extinction, as long as people get married, it's not much of a problem.

The real reason for low TFR is mainly the lack of marriage itself. So the author is wrong about economic/financial reasons for people not making children. The actual reason is that they don't even want to get married in the first place (and then you could make a case for economic reasons why people are not getting married). If we are going to talk about declining birth rate or TFR, we should instead be asking about why marriage is on a decline.