when I was sick I had a fever
June 13, 2019 11:27 AM   Subscribe

James Lovelock and Lynn Margulis proposed the Gaia Hypothesis of life on Earth in a vast interrelated self-stable complex system , named after a Greek primordial goddess. But what if our idea of feedback is incorrect? What if Life On Earth Is Ultimately Self-Destructive, as laid out in Peter Ward's Medea Hypothesis?

The Medea Hypothesis: A response to the Gaia hypothesis
Most of the book is a systematic and fascinating dismantling of the assumptions underlying Gaia hypothesis. First are Earth's five mass extinctions. Microbes, Ward says, are implicated in all but one of these die-offs, the K-T extinction thought to have been initiated by a meteor strike 65 million years ago.

The broader point: Repeatedly throughout Earth's history, organic life, in the form of anaerobic microbes that normally inhabit oxygen-starved nooks and crannies, have emerged to extinguish life. These microbes exhale hydrogen sulfide, a gas poisonous to other life forms.
Mother Nature's Dark Side
Ward’s arguments are fascinating but fraught with inconsistencies. For example, he contends that the Gaia hypothesis is not testable—but then provides evidence that supposedly refutes it. It seems that the Medea hypothesis is necessary—but not sufficient—to explain global ecology.

Arguing whether Ward’s or Lovelock’s hypothesis is right is like the fruitless debate of nature versus nurture. The real question is: Under what conditions are biological systems Gaian or Medean? And if life is globally self-destructive over the long haul, what are we supposed to do?
Ward criticizes environmentalism and environmental philosophy (although he muddles these enterprises and creates an outdated straw man). He dismisses going “back to nature” and advocates various technologies (e.g., limited airline travel by jet) to solve the contemporary excesses of CO2, but he offers little to stave off future shortages. As I see it, if we solve the current problem, then humans score a point for Gaia and have a billion years to work on Medea’s hypothetical depletion.
THE EARTH IS ABOUT TO CATCH A MORBID FEVER THAT MAY LAST AS LONG AS 100,000 YEARS, James Lovelock

Scientists finally have an explanation for the ‘Gaia puzzle’
The relevance of our findings to current concerns over climate change has not escaped us. Whatever humans do life will carry on in one way or another. But if we continue to emit greenhouse gasses and so change the atmosphere, then we risk producing dangerous and potentially runaway climate change. This could eventually stop human civilisation affecting the atmosphere, if only because there will not be any human civilisation left.

Gaian self-regulation may be very effective. But there is no evidence that it prefers one form of life over another. Countless species have emerged and then disappeared from the Earth over the past 3.7 billion years. We have no reason to think that Homo sapiens are any different in that respect.
posted by the man of twists and turns (16 comments total) 33 users marked this as a favorite
 
Damn, I had no idea that these Tyler Perry movies were so bleak.
posted by NoMich at 11:51 AM on June 13 [14 favorites]


Previously, although your post is more filled out.
posted by thatwhichfalls at 11:54 AM on June 13


The argument about mass extinction seems irrelevant, because in none of those cases did the event end all life. One could just as easily argue that evolutionary bottlenecks are one of the favorable (on the geological timescale) conditions that the self regulating system provides. I also don't really see a contradiction between the two ideas. The feedback loop of life affecting the environment which in turn affects life is a driver of increased ecosystem complexity. At the same time, the processes of life use resources, and could run our of them. But, it's a bit of a logical twist to say that means life is self destructive. Earth might have more bio-available carbon if there was no life, but it seems quite strange to claim that this would be less destructive of life than you know, if it existed.
posted by Nothing at 12:29 PM on June 13 [5 favorites]


Since this is all story-telling, here is another story. Let us call it the Lost Eden Hypothesis.

About 700 million years ago, a form of life arose that was so destructive it exiled most living things to living underground or underwater by excreting a gas so reactive that it killed almost everything it touched. The form of life was plants. The gas is oxygen. The exiled form of life is anaerobic bacteria, still the most numerous living things.

It may be that someday plants' unbalanced, destructive nature, and that of their various parasites, will be their downfall, and Earth will be returned to its original Edenic state.
posted by ckridge at 1:18 PM on June 13 [39 favorites]


Le Chatelier's Principle: The system tends to oppose its own proper functioning.

The first photosynthesizers released oxygen and created an ecological niche for organisms that require oxygen and consume photosynthesizers. A fire burns across a prairie and uses up the fuel it needs to burn. All processes are self limiting sooner or later. There's not really any difference between Gaia and Medea; self destruction is the force that enables stable systems.

Ecologically, the choice for humans is whether we want to limit ourselves voluntarily and at least partly on our own terms, or wait for the rest of the system to impose limits. The second option is not going to be pleasant for anyone involved.
posted by echo target at 2:15 PM on June 13 [5 favorites]



Ecologically, the choice for humans is whether we want to limit ourselves voluntarily and at least partly on our own terms, or wait for the rest of the system to impose limits. The second option is not going to be pleasant for anyone involved.


Speak for yourself! 🦠

I was going to register a sock account for this comment called "totally not cyanobacteria commenting here" but you now have to wait a WEEK before getting a new username? PAH
posted by lalochezia at 2:30 PM on June 13 [9 favorites]


self destruction is the force that enables stable systems

And also, life tends to maximize entropy: not within ourselves, or we would be destroyed; so somewhere else in our state-space. But not too far away, that's too much work.
posted by clew at 2:54 PM on June 13


One could just as easily argue that evolutionary bottlenecks are one of the favorable (on the geological timescale) conditions that the self regulating system provides

The Cronus Hypothesis: Extinction as a Necessary and Dynamic Balance to Evolutionary Diversification , Corey J. A. Bradshaw, Ph.D. and Barry W. Brook, Journal of Cosmology, 2009, Vol 2, pages 221-229 In PRESS Cosmology, October 8, 2009

Life and death on Earth: the Cronus hypothesis
Enter Cronus. Here we posit a new way of looking at the tumultuous history of life and death on Earth that effectively relegates Gaia and Medea to opposite ends of a spectrum. Cronus (patricidal son of Gaia overthrown by his own son, Zeus, and banished to Hades) treats speciation and extinction as birth and death in a ‘metapopulation’ of species assemblages split into biogeographic realms. Catastrophic extinction events can be brought about via species engineering their surroundings by passively modifying the delicate balance of oxygen, carbon dioxide and methane – indeed, humans might be the next species to fall victim to our own Medean tendencies. But extinction opens up new niches that eventually elicit speciation, and under conditions of relative environmental stability, specialists evolve because they are (at least temporarily) competitive under those conditions. When conditions change again, extinction ensues because not all can adapt quickly enough. Just as all individuals born in a population must eventually die, extinction is a necessary termination.
Enter the Plutocene
posted by the man of twists and turns at 3:17 PM on June 13 [2 favorites]


i think it's pretty well accepted that the main objective of all life forms is to perpetuate themselves. since life has existed on earth for billions of years, it seems unlikely that it inherently has a tendency to self-destruct. but that definitely doesnt imply any sort of gaian homeostasis either. sometimes life perpetuates itself by changing itself via evolution or changing its environment quite radically. in fact, adaptability to change is a hallmark of evolutionary biology, which is to say, all biology.

so life can and likely will persist on earth even if it's in a form and in an environment that humans might consider a total hellscape. neither the rock that is the earth, the biosphere that exists on it, or the future life in that biosphere will share our human normative judgments.
posted by wibari at 3:52 PM on June 13


To tell it in other terms:

In A.S. Byatt's fine retelling of Norse myth, Ragnarok: The End of the Gods, Frigg, the earth and mother goddess, almost keeps it from happening. She gets every living thing but one to promise not to kill Baldur, and then she gets every living thing but one to weep for him, which would have bought him back from Hel. At the end, she does not go out to fight, but sits in her burning hall and watches it all fall down.

It occurs to me that what we are killing is just precisely our mother. We can, and likely will, wipe out or ruin everything kin to us and everything that we are naturally disposed to love, but we cannot possibly wipe out any significant fraction of life. You can burn all humanity and kindness out of Frigg, but that does not diminish her. There is no pollutant we can produce that some bacterium can't use as an energy source.
posted by ckridge at 4:36 PM on June 13 [3 favorites]


When I was a child I had a fever
My hands felt just like two balloons
Now I've got that feeling once again
I can't explain you would not understand
This is not how I am
I have become comfortably numb
posted by adam hominem at 6:13 PM on June 13 [3 favorites]


There are some scientists that say Venus was once like Earth but got caught up in an ever increasing global warming feedback loop. It's not going to go back to being amenable to life.

This life tends toward extinction theory is postulated as one reason why we haven't encountered evidence of intelligent life on other worlds or in space. Life is brief by nature, and tends to build to extinction events.
posted by xammerboy at 9:18 PM on June 13


The more we learn about the planet, the more it becomes apparent that we evolved in an exceptional window of time, an interval when the planetary system established a balance that encouraged the development of very complex life.

This is the garden of Eden. At least for a little while longer.

The question is, have we developed enough technology to allow us to survive without a habitable planet to support us? Can our species survive through this extinction event? When the planet turns against us, will we be ready?

If we can't save the biosphere, can we at least save humanity?
posted by MrVisible at 5:33 AM on June 14 [2 favorites]


i think it's pretty well accepted that the main objective of all life forms is to perpetuate themselves.

I'd say 'tendency' rather than 'objective'. I mean, this is basically defining survivorship bias.

since life has existed on earth for billions of years, it seems unlikely that it inherently has a tendency to self-destruct.

Did dodos self-destruct? Thylacines?
posted by pompomtom at 6:40 AM on June 14 [1 favorite]


If the members of a species can contemplate and predict the effects of their actions, and have the means to avoid either self-destruction or destroying their habitat, that's not "nature", that's morality. I've had it with denier types who say that the human drive to grow and "profit" at the expense of everything else, including our own future, is simply part of nature.
posted by Artful Codger at 4:27 PM on June 15 [1 favorite]




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