This is bad news for we the people

The origin of multicellular life, one of the most important developments in Earth’s history, could have occurred with surprising speed, US researchers have shown. In the lab, a single-celled yeast (Saccharomyces cerevisiae) took less than 60 days to evolve into many-celled clusters that behaved as individuals. The clusters even developed a primitive division of labour, with some cells dying so that others could grow and reproduce.

It suggests that “the filter” lies ahead of us rather than behind us.  The difficulties of producing multi-cellular organisms have been one of the main responses to the Fermi Paradox (“where are they?”).  If it’s not so hard after all, there must be some other obstacle to lots of self-reproducing von Neumann probes.

The link is here.  Speaking of bad news, here is a bad news argument about Chinese real estate.

Comments

Bad news? Why?

"Bad news? Why?"

The implication is that something will happen to the human species preventing us from getting off-planet.

This seems a backward way of looking at things. I'd say a hell of a lot would have to happen to allow us to get off planet.

Not really, we could build a nuclear-powered starship today, were we so inclined.

http://en.wikipedia.org/wiki/Project_Orion_%28nuclear_propulsion%29

Not really. We don't have anything resembling the space infrastructure necessary to assemble a 100,000 ton starship in orbit, for example.

That's assuming that the technology works out fine. I have some concerns, such as the relatively short effective "lives" of some of the nuclear bomb components (such as Tritium), as well as the technical complexities in designing a spaceship to last for the dozens to hundreds of years that an interstellar trip would require.

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No Brett,
Project orion was designed to be assembled on the ground, using 1950s technology, and launched from there into space.
The 1950s project group concluded there was nothing technological to stop them doing it right then, if the USA was prepared to fund it.
The USA was not.

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"us" not "we": grammar probably evolved pretty quickly too.

He did it intentionally. :)

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There is a Great Filter preventing life from spreading across the galaxy. It may be ahead of us or in front of us. One possibility for the Great Filter was multi-cellular organization. That seems not to be the case. Increases probability that Great Filter lies ahead.

or behind us

Well, I love sci-fi :D
I remember reading a sci-fi comic many years ago depicting earth as an experiment lead by super-advanced aliens intending to test evolutionary outputs on planet scale. In that case the answer to Fermi's paradox was: "We are here!"
I don't remember if this was also the main theme behind Robotech saga...
Anyway I am still wondering why we're trying to send humans to Mars instead of engineering bacteria in order to survive on Venus... maybe with a genetic code made from something different from DNA or RNA... but it's still sci-fi in my mind...

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The great filter is just that there isn't an earthlike planet within 100 light years.

Really? How do we know that? Can you direct me to where I can get some info on that? I don't doubt that you're right it just surprises me.

That distance is the most likely candidate seems obvious to me.

I agree. The immense distances between even the nearest stars combined with what would appear to be vast physical difficulties in approaching even a significant fraction of the speed of light let alone surpassing it would appear to be a likely candidate.

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Intergalactic distances aren't likely to stop "self-reproducing von Neumann probes."

You've got your scale off. One alien race capable of building them could have sent one to every star in the galaxy over the course of 10 million years assuming a maximum speed of 2% of the speed of light. That assumes average dispersal speed would be at least 1%. Since multi-cellular life on this planet has existed for over 1,000 million years, the distances are significant but hardly a plausible reason why we've never seen one.

However, time is a better answer. If there have been 1 million advanced star-faring alien races over the last billion years in this galaxy; And if 10% of them have bothered to send a probe to every star; then we'd see a probe roughly every 10,000 years. How long has it been since we would even spot it or recognize what it was?

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Heck, they could have sent a probe through the solar system as recently as 500-600 years ago, and we'd be none the wiser because telescopes were still in their relative infancy.

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First, Kepler suggests that there probably are some. At least dozens.

Second, why is that Great Filter? Life fills niches. Unless warp travel exists, colonizers will try to fit into each system, not wait for the best one to show up.

Kepler suggests planets are common, but says nothing about the stars in a 100 light year cube around us.

Go look at http://www.exosolar.net/ and see how planet candidates are out there.

A SETI guy reporting on Kepler said this a year ago based on its early results:

"Within a thousand light-years of Earth -- a distance that could be bridged by transmitters no more powerful than equipment we ourselves can build -- there are at least 30,000 of these habitable worlds."

Assuming spherical distribution (worst-case), that's still 30 within 100 light years.

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I'd question that until our planet-detecting capabilities improve. Kepler seems to be finding a fair number of planets close to Earth in size (and a few even smaller), even when you factor in its limitations (it has to catch solar systems "edge-on" in order to reliably observe transits of the planet around the star, which means that it can't examine many stars).

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Well, it's an interesting academic argument but scientifically -- I think that doing what they did with _yeast_ is a lot easier than doing it with other unicellular organisms (yeast came from a multicellular predecessor). Picking the right system will be interesting; a lot of bacteia form fruiting bodies, for example. But it's probably a lot easier to reawaken old pathways than to design something "from scratch" and what they did is more the former.

Oh, Sanjay, this is an Economics blog. It's bad etiquette to drag in science.

When I was house shopping we put together a list of things. The realtor said, that's too many, you'll never get all that. So, we pared down. "Still too many." We got it down to one- decent commute. We found a nice house- terrible commute.

The point being, don't underestimate the power of a lot of little filters.

I'm pretty sure the only point there is that you're not a rational actor. Welcome to the club.

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Another possible filter: the move from a prokaryote to a eukaryote?

And wouldn't interstellar bacterial spores (if they are found) make a good self-replicating Von Neumann probe?

besides DNA, you mean?

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+1

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To be fair, the guy behind the experiment recognized this. The end of the article mentions that he's going to try it with single-celled organisms without a history of multi-cellular organization, such as blue algae.

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Life starting can be rare (don't be deluded by how fast life appeared on Earth, it may be that it could only appear fast).

Life starting to use proteins can be rare.

Life expanding the amount of amino-acids it metabolises to a number that can create something complex can be rare.

Life surviving the transition to an oxygen athmosphere can be rare. (But I wouldn't bet on this.)

Life getting on land can be rare.

Life getting fast (hot blooded) can be rare. (But I wouldn't bet on this.)

Inteligent life can be rare.

There are plenty of possible filters at the past. In fact, they are very likely more restrictive than any future filter you'll find people talking about. Climate change and worldwide war? What are the odds of a civilzation avoiding those before it jumps into space? I bet it is highter than 10^-6, but probabilities way lower than 10^-6 are quite plausible for all the filters I cited above.

I tend to think the odds of climate change and future world wars are high. However, I think the they are unlikely to lead to human extinction. 10,000 or so survivors out of 6 billion would be plenty to insure survival.

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Is climate change really supposed to wipe out humanity? On the scale of things, at worst it would probably set it back a few centuries.

Or it may make things better - which is the way I'd bet.

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Q; What is the filter preventing flying cars?
A; There is none.

Q; Where are the flying cars?
A; The priors of the people who imagined a future of flying cars were wrong.

Why imagine a filter when it is easier to think that your priors are wrong.

What is the filter preventing flying cars? Energy storage density, fuel efficiency, control complexity, safety, cost, and regulation.

Where are the flying cars? We call the current models "helicopters". Institutions which need and can afford flying cars have them; the rest don't.

What exactly was your analogy supposed to mean, again? "Why imagine a filter"? Because it's a tautology! If you see that something can happen, but you also see that it isn't happening, then there must be something that's preventing it from happening. If you see what that something is, you've got your filter. If you don't see what that something is, then you've got a hidden filter and a puzzle.

And "to think that your priors are wrong" is what we're doing *right now*. The whole point of the Fermi Paradox is that we can practically prove that some of our priors must be grossly wrong; debating what the Great Filter is means we're trying to figure out *which* priors are most wrong.

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The whole point of the Great Filter is to figure out which of the priors are wrong.

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We have flying cars. They're called planes.

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Thank you, robbl. The epistemic immodesty on display here is in striking contrast to Tyler's normal style of thinking.

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The "filter" is more likely that earthlike planets are just rare enough for radio emmissions from other intelligences to not yet have reached us.

Key word "radio". Seriously, how long have we used radio? It's a blink of an eye in historical terms. And at what average intensity? We don't intentionally broadcast at a level that you could easily receive on Mars, let alone another star. Also a bonus if you realize that as our technology gets better, we are reducing the wattage behind our broadcasts. Honestly, how long before the Earth emits essentially no radio broadcasts.

Radio is probably the wrong medium. What are the odds that an intelligent race that has achieved industrialization is still using radio very much 1,000 years later? I suspect the time period of high radio usage is relatively short. Are we scanning the night time skies for smoke signals or carrier pigeons also?

> We don’t intentionally broadcast at a level that you could easily receive on Mars, let alone another star.

Early warning radar would easily be visible at interstellar distances, orders of magnitude brighter than the sun, to say nothing of interplanetary mapping radar. It's not episodes of "I love Lucy," but it would be pretty obviously artificial.

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Key word “radio”. Seriously, how long have we used radio? It’s a blink of an eye in historical terms. And at what average intensity? We don’t intentionally broadcast at a level that you could easily receive on Mars, let alone another star. Also a bonus if you realize that as our technology gets better, we are reducing the wattage behind our broadcasts. Honestly, how long before the Earth emits essentially no radio broadcasts.

It's even worse when you consider that most of our radio broadcasts are now done in digital form, meaning that they would be indistinguishable from background noise if some alien civilization somehow picked up on one of them.

Digital waveforms and white noise are distinctly different, and nature does not create digital waveforms that look anything like our digital radio broadcasts. As you say deciphering a digital broadcast would be be as useless as deciphering white noise for an alien. But the alien could follow the broadcast right back to the transmitter. The larger question is if any alien space-faring race is looking for radio broadcasts.

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There's a lot of baseless speculation in these Fermi Paradox arguments. Consider how little we knew about the prevalence of planets just ten years ago. Consider how we didn't understand gamma bursts a few decades before that. We really don't know beans about the interstellar medium, how dangerous it is, what kind of tech it would take to cross it, how long it would take. We know a lot more about planets but we still don't know how common it is for one in the temperate zone to have a big moon and for there to be few enough asteroid strikes to allow an intelligent civilization to develop.

Remember that life can't develop on planets of a Population I star -- you have to have a star formed of the remnants of a supernova, i.e. Pop II, to have the heavier elements. So it remains reasonable to suppose that we are contemporaneous with the first technological civilizations. We won't have solid evidence about how fast interstellar vN probes can spread -- including travel and reproduction time --until we make one that works. Almost certainly vN probes need Pop II stars as well. Most likely they will travel along the spiral arms, not in straight lines.

So it's hardly a stretch to imagine that probes from a star say 40kLY away could take many millions of years to get here.

... on the other hand, imagine that any planetary civilization develops along the lines of ancient China instead of medieval Europe -- a centralized bureaucracy with built-in stagnation in its organizational genes. There's plenty of evidence that the activists for world government and technological stagnation here and now are the same folks. That plus the occasional asteroid impact would make a good Great Filter.

My favorite candidate, though, is worldwide weather control technology (such as my Weather Machine), wielded by folks with the same hubris as the Fed used in the 30s ... instead of a depression, you get an ice age.

I find it amusing that your first sentence highlights how much scientists got wrong or didn't know in decades past but you then go on to assert that "life can’t develop on planets of a Population I star."

How many years before that assumption - along with all others about what conditions are "required" for multicellular life to form - is debunked, I wonder?

There are no heavy elements, just Hydrogen and Helium - I think that's what was implied.

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Even if life is widespread in the universe, sophisticated radiological technology may not be. If civilization were an inevitable side effect of multicellular evolution, why did it take so long to happen on earth, and why has it only happened for one species? I think Gould was right when he insisted that only small differences in the historical antecedents of our species could have completely changed the landscape of biology, among other things preventing the development of human or human-like intelligent life.

On top of that, what makes multiple instances of technologically capable species more likely, the sheer hugeness and complexity of the universe, is the very thing that makes them hard to find in the first place. It's a little like saying that there must be a needle in the haystack, because the haystack is so fucking big. Maybe, but good luck getting your hands on the fucker if its there.

There are also, definitely, time slice problems that are not well considered. We've only been capable of scanning the universe for others like us for a century or so. The universe is 14 billion years old. It may be that the last in range technological civilization with radio telescopes and cable television died off fifty million years ago, and it may be they spent a huge amount of effort failing to find us. That wouldn't even be that long ago, in the relevant scale of things. This could have happened again and again, dozens of times in different places. We don't have a very good sense of how long technologically advanced cultures can sustain themselves. If we're generous, and mark the development of agriculture as the point where we started to count as civilized, we've only been around for 12000 years, which is still less than a heartbeat in astronomical terms. We have no idea how long a run we have any chance of making. If the typical run of a civilization is a million years, you would still have to get really lucky to be around at the appropriate time to intercept the communications of smart aliens from another planet.

Also, I sort of think the longevity of life on our planet may be quite exceptional. We've had life for most of the time the planet has existed (3.6-3.9 billion years out of 4.6 billion), and we can expect to have life at least another billion years before we start running into problems. That means we've had life (although mostly unicellular life, still life) for a substantial fraction of the time the universe has been around. It may be more likely that you see biospheres that pop in and out of existence on much shorter scales-100 million year ecologies (something like this may have occurred on Mars, for instance), and that the conditions required to consistently support complex life over extremely long time frames may be exceedingly rare. If the typical time span of planetary ecologies is less than a billion years, that both greatly reduces the odds that intelligent life with develop elsewhere as well as the odds that multiple civilizations will develop simultaneously.

+1

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"If civilization were an inevitable side effect of multicellular evolution, why did it take so long to happen on earth, and why has it only happened for one species?"

I think it is quite possible that mulitple civilitizations of different species don't exist not because civilizations are soo rare but because the existence of the first civilizing species causes the extinction of later ones. At least until it grows up enough to be more tolerant (or obtains an unasailably secure position depending on your point of view).

As possible evidence for this I point to the extinction of Neanderthals and recent evidence of culture (locally shared and learned behavior lasting generations.) in animals as diverse as dolphins and crows. Thier smarter then we used to give them credit for.

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Advanced alien species: "Crap! Hey universe, whatever you do, don't overcharge your solar fusion power sources! We repeat, don't--AHHHH!!!!!"

Meanwhile, on Earth: "A new star was observed to appear in the year 1054."

"Children of the stars. You will never know us, and we do not have time to say much."

"We have one lesson we failed to learn that we hope you will: You can't add too much water to a nuclear reactor."

The Japanese can.

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This basically nullified the whole argument:

Yeast evolved from multicellular ancestors, so it is possible that they had an easier time of recreating their ancient lifestyle.

That seems much more likely, given that it took 1.8B years for multicelllular life to develop.

I will second this and this fact seems to have been ignored in the popularization of the result.

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The authors of Power, Sex, Suicide suggest the "filter" was archaea and bacteria merging to form eukaryotic cells.

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I subscribe to the filter being that Inner Space is much easier to navigate than Outer Space. Relating to Stephen Webb's book, it's "They Stay Home and Surf The Net"---see also Geoffrey Miller's 2006 Edge essay and chess GM Yasser Seirawan's item here (where Miller is linked too).

If there is some sort of Artificial intelligence explosion in our near future, we will find our brain processing speed rapidly increasing. This means our perception of time would rapidly slow down, relative to our thoughts.
Subjectively, a future human who thinks 100 times faster than us, would find a 4 year journey to alpha centuri to take 400 years. The faster technology gets, the more distant the stars grow in subjective time.
Furthermore, the more everyone becomes interconnected by modern communications, the less willing they will be to spend years isolated on voyages of discovery. How many sailors now would sign up for a 7 year voyage around the world in a 50 foot sailing ship as many did centuries ago?
It may be that a huge, dumb, nuclear powered, project orion style project by a pre-singularity civilization may be the only chance of interstellar travel, and we may be past that stage.

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I'm skeptical of the results of this study. It seems to have taken a relatively long time for multicellular life to develop, as it's been around for only 500 million years out of the 3.7 billion (or so) life has existed on Earth. If it were as easy to form as this study claims, then wouldn't we have expected its emergence earlier? After all, once it did form, it essentially gained a new ecological niche to fill and hence there was the Cambrian Explosion of forms of new multicellular life. Hopefully the puzzle will be unraveled in my lifetime.

Multi-cellular life actually preceded the Cambrian Explosion, and we've found traces of that. It's just harder to do so, since it's harder to find organisms that were preserved before the evolution of hard exo- and endo-skeletons.

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The claim that this is bad news runs into the Raven Paradox: http://en.wikipedia.org/wiki/Raven_paradox
There are so many possible filters, that it feels impossible to make any estimates at this point.

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any sentient intelligence advanced enough to be able to meet and greet other species would by necessity already have freed itself of the genetically inherited instinctual passions which cripple any intelligence well before it can even (actually) recognize itself. consequently, the individuals that make up that species would no longer impulsively psychologically project their species' hoary-herd-mentality 'need to belong' onto (imaginary) 'other species' that 'must be out there', and wouldn't even extend a single hand to the sky (let alone embark on a space expedition). they will smile and think: why go elsewhere when here is already perfect? we will always be alone in this universe, just as we always have been ... and that's not even relevant to the problem.

incidentally, i think humanity is probably already filtered 'out' on this matter. there was a near miss during the bronze age when a bunch of homeless guys decided that harmlessness was the cure-all, but now the majority of thought there given is toward how to venerate and worship giant gold statues of their likeness.

there's said to be a modern way out of the human condition, too; but the thing is, it screams 'cult' to the over-psychologized western audience it was written for, so the odds of that picking up are slim-to-none. really, google it and look: freedom from the human condition.

wait ... where's my optimism? how hard could it be to rationally talk the majority of seven billion humans each out of dozens of addictions they don't even realize they're each personally enslaved to? who wants to break the news to their father? "dear sir who raised me, your sense of identity is the great filter, please do something about this." haha.

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My personal favorite is the "Content to Stay at Home" hypothesis. I think that any alien civilization that survives long enough eventually reaches a point where their technology plateaus*, and they develop the capability to both constrain population growth** and provide a very comfortable, stable standard of living for their population. At that point, the risks and expenses of leaving your own solar system become even more of an issue, and interstellar voyages are already quite expensive in energy and resources (at least from our own attempts at designing them). Why give up all the comforts of home, including long life/immortality and a high standard of living, in order to spend decades in transit just to get to the nearest stars?

Even sending probes to the nearest stars would be difficult. You'd either need to spend the energy and time building a relatively "fast" probe, or face the technical issues involved in designing a probe that would remain functional for thousands of years while drifting in interstellar space. Tyler brings up the "Von Neuman probe" concern, but we honestly don't know enough to determine whether it's even possible to design and build a self-replicating interstellar probe. Simply building more and better telescopes in space is far cheaper and easier, even if they don't provide as much useful information as an actual probe in another solar system.

* "Plateaus" in the sense that they reap all the gains from technology that the laws of physics permits, and which their civilization is willing to pay the price for utilizing in terms of energy, money, and resources. For example, it might be possible to build an anti-matter rocket . . . if you're willing to build a ton of solar-powered particle colliders in the inner solar system to create a sizeable fuel supply. That doesn't mean a civilization will do so.

** I put "constrain" down because we don't know how population growth will affect an alien civilization. All we have as an example is human civilization, which is moving towards a "leveling off" point in population growth due to the Demographic Transition. Perhaps alien civilizations go through the same thing, or perhaps not.

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The Great Filter is concerning only if your metric for civilizations is "electromagnetic signals detectable as such with current Earth technology". Granted, if we want to look, we have to start looking somewhere, but there are many, many assumptions built in to using that metric:

1) That intelligence is adaptive in the evolutionary long run (this is exactly the concern of Great Filter worriers)

2) That electromagnetic communication is used for long periods of time after its adoption. If not, at any one point in time, you wouldn't hear many: either they move on, or there's a penalty to being electromagnetically loud so only the quiet intelligences persist. (Imagine the Mayans building signal fires on the beach to help the Spanish find them. Apologies for the drama, but you get the point, and that was intra-species.)

3) That we know what we're looking for.

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If intelligent aliens know about us, they would probably want to keep us in the dark about it.

After all, we try to keep "uncontacted" cave men in isolation. Knowing them is to understand ourselves etc., as some paleontologist would put it.

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