Intelligence as we know it a rarely-evolved trait in the universe?

[brian0918]

I had this debate with a friend recently. I argued that if life as we know it is common in the universe, then intelligent life is more likely to occur. Using Drake's equation, it would seem that there are most likely numerous examples of intelligent life in the universe, or at least a large enough chance for them to occur to make it seem common.

He argued that because, in the case of humans, intelligence was a trait evolved as a result of specific pressures from the environment, it is less likely that the same environmental pressures will occur for other possible lifeforms out there, making intelligence much less likely.

Because these planets are complex dynamic systems, it makes predicting an outcome (such as how likely intelligent life is to evolve in the future) basically impossible. A slight change to our planet a million years ago would probably result in our present day being completely different.

This would make it seem like intelligent life is extremely rare in the universe.

He was basically saying that intelligence isn't something life strives for, which I agree with. I went on to say that intelligence may come about in many different ways, making it more likely in the universe.

Anyone care to add their own comments?

 

[uruk]

intelligence is pretty rare on this planet also



sorry. I wanted to be first in posting this stupid joke to get it out of the way.

the joke i mean.

 

[SGT]

Earth is hosting life for about 3 billion years. Inteligence arose about 100000 years ago. A tiny fraction of life history in the planet.
Mammals, including human beings are the result of at least two mass extinctions, that made the dominant life forms to disapear. So it seems that we are the result of accidents in the history of life.
In the other way, inteligence is obviously a great evolutionary advantage, so it is possible that it could evolve in another species.

 

[Interesting Ian]

Earth is hosting life for about 3 billion years. Inteligence arose about 100000 years ago.

Huh??


Where on earth do you get 100,000 years from? Intelligent creatures, such as for example dolphins, were around a long time before that!

 

[Navigator]

Huh??


Where on earth do you get 100,000 years from? Intelligent creatures, such as for example dolphins, were around a long time before that!

Agreed

Intelligence comes in a variety of forms.
Depending on the form, the tools available of that form help the intelligence to create, explore and sometime contemplate.

There is no reason to suspect tht Dinosaurs were lacking intelligence either.



The thing about 'life on other planets' is that although it is not a proven fact, it is rather a certainty, given the infinite variables.

"Life" itself signifies for me something more than the ordinary educated understanding as to 'what life is'...but what the hey!

We can learn a lot by not only observing the general behaviour of Dolphins, but by adopting some of those social behaviours for our human selves.

 

[brian0918]

In the other way, inteligence is obviously a great evolutionary advantage, so it is possible that it could evolve in another species.

It was an advantage to us when it started to develop, given the environmental pressures of the time. Intelligence allowed us to build better tools, to hunt better, and to better adapt to environmental changes. So yes, it is of great advantage, but the necessary circumstances need to come about for it to evolve and endure. I highly doubt that the same circumstances our ancestors were placed in (that brought us about) will occur on other planets, since any slight change in initial conditions will result in a vastly different result.

 

[davefoc]

My own personal appraisal of how common human like intelligence is in the universe has declined somewhat over the years.

Among the reasons are:
1. An article in Scientific American claimed that intelligent life was probably only possible in a narrow ring of stars around the center of the galaxy. I have forgotten the details but basically the idea was in some places the star systems don't have enough metallic elements (meaning non-hydrogen in this context) to make life possible and in other places the stars are too close together and there is just too much radiation to allow for life to develop. So there's a lot fewer stars in our galaxy and other galaxies than were previously thought where life is possible.

2. SETI has been searching long enough and in a sophisticated enough way to begin to suggest that there aren't life forms on stars very near to us that are capable of beaming non-randomly modulated electromagnetic radiation our way which is probably a capability of all high technology civilizations in the universe eventually.

3. A personal conjecture that the nature of human like intelligent life is that it eventually destroys itself through its own technological advancements before the technology for long distance space flight is developed. If this is true the life span of high technology civilizations may be very short so the number of high technology civilizations in the universe may be very smal at any one time.

4. The lack of evidence for extraterrestial visitors on earth suggests that extraterrestial space flight by non-humans is either very rare (since they've had billions of years to visit us) or the extraterrestials don't leave much evidence when they come to visit. I think the former possibility is the most likely and that suggests there probably aren't any extraterrestials flying around near earth which further suggests that high technology extra terrestial civilizations are rare or non-existant near us.

I do think that human like extraterrestial intelligence does exist in the universe, but I think it is rare and is likely separated enough in distance from us to make ever finding evidence of it an unlikely proposition.

 

[CurtC]

SETI has demonstrated only that there is no intelligent life sending out radio signals in our tiny corner of our own galaxy. I agree that intelligent life is rare, relative to general life, and I'm doubtful of the statement that intelligence is an evolutionary advantage. It was for our particular circumstances, but I think there were some unique things that happened along our way. Intelligence is costly to us in many ways, and it just so happens that the positives for us slightly outweighed the negatives.

That having been said, even if you figure that there was only a 10% chance of intelligence arising anywhere in our whole galaxy, there are still tens of billions of galaxies out there.

 

[SGT]

SETI has demonstrated only that there is no intelligent life sending out radio signals in our tiny corner of our own galaxy. I agree that intelligent life is rare, relative to general life, and I'm doubtful of the statement that intelligence is an evolutionary advantage. It was for our particular circumstances, but I think there were some unique things that happened along our way. Intelligence is costly to us in many ways, and it just so happens that the positives for us slightly outweighed the negatives.

That having been said, even if you figure that there was only a 10% chance of intelligence arising anywhere in our whole galaxy, there are still tens of billions of galaxies out there.

We must realize that SETI depends not only in the spatial distribution of technological civilizations, but in their time distribution.
As davefoc mentioned, technological civilizations have the power of self destruction. Our own civilization was very near that in the sixties.
On Earth, advanced technology is less than 300 years old, or 0.00001% of the time life has been present in the planet. The ability to comunicate by electromagnetic means is even more recent: 100 years.
If the average life of a technological civilization is only a few hundred years, it is not likely that we will be able to contact another such society before our own extinction.

 

[scribble]

The thing about 'life on other planets' is that although it is not a proven fact, it is rather a certainty, given the infinite variables.

Exactly which factor in the Drake equation is infinite?

 

[Bottle or the Gun]

Dolphins are clever, yes, but intelligent? If they behaved the same way but looked like slime dripping scabs I doubt they'd be considered smart. I think the cuteness factor influences what people think of Dolphons. I understand they might be pretty smart if so much of the brain wasn't used for interpreting their sonar.

 

[drkitten]

Dolphins are clever, yes, but intelligent? If they behaved the same way but looked like slime dripping scabs I doubt they'd be considered smart. I think the cuteness factor influences what people think of Dolphons. I understand they might be pretty smart if so much of the brain wasn't used for interpreting their sonar.

Depends on what you mean by "intelligent." (Of course.) They typically can learn complex tricks better that most cats or dogs, and they're among the few animals for which we have clear examples of higher-order cognitive abilities (such as the ability to recognize themselves in a mirror). On the other hand, they're not likely to be able to pass a physiology class or direct a light opera.

Even if they looked like slime dripping scabs, they'd still test better than most land mammals.

 

[Frostbite]

Certain mollusks like octopi are actually pretty smart. They have short and long term memory and can learn from their mistakes. And to control 8 arms at once requires a certain capacity to process data.

And as for all that SETI and Drake equation stuff, I'd say they're rather meaningless and all based on no evidence at all. Who is to say that aliens would be using radio waves anyway? Or sending them in our direction? And who's to say that the closest intelligent aliens hasn't vanished a billion years ago? And as far as I know, SETI actually came across a couple intriguing signals that remain to this day unexplained.

But seeing that they've been scanning static for the last 20 years I'd say that the odds of having intelligent life anywhere near our star system is rather thin.

 

[SGT]

And as for all that SETI and Drake equation stuff, I'd say they're rather meaningless and all based on no evidence at all. Who is to say that aliens would be using radio waves anyway?

Ants communicate using pheromones. We could assume that inteligent aliens could use similar communications means. I don't see any means how smell could be used to modulate an electromagnetic wave and if there is any, we would not be able to demodulate it.

 

[drkitten]

Certain mollusks like octopi are actually pretty smart. They have short and long term memory and can learn from their mistakes. And to control 8 arms at once requires a certain capacity to process data.

What does "smart" mean in this context? I can make a pretty strong case that octopi aren't as smart as most mammals, or even many birds. I have an easier time demonstrating they're not as smart as humans.

The Drake equation uses a practical definition of "intelligence," which is basically the ability to receive/send radio signals. By that definition, H. sapiens is the only "intelligent" form of life on the planet, and only achieved "intelligence" a hundred years ago. I like to think, though, that Newton was "intelligent," so I would be inclined to use a much more relaxed definition.... I just don't have a useful one to offer.

 

[simong]

There are some interesting theories about why intelligence might be rare
in the Universe. The Earth is pretty special in two main ways which could help intelligence evolve.

Firstly, Earth has a *big* moon. This stabalises the Earth's roatation axis and stops it flipping about every few tens of millions of years. This means the Earth has a stable climate which allows animals to evolve slowly. Quick changes in climate would presumably kill-off lots of advanced animals.

Secondly, the solar system has Jupiter to act as a 'comet hoover' and reduce massively the flux of comets into the inner solar system. This reduces the number of comet impacts and provides long periods of stability between dinosaur killer-type events.

Without these two things its unlikely the Earth's climate would have been stable for long enough for very advanced life and intelligence to develop.

As well as that, the Sun seems to be a very stable star. It doesn't often seem to get very active which would strip the outer atmosphere and flood the surface with UV and radiation.

A statistical argument has been made to show that life is common. It took about 100 Myr (million years) for life to form out of the 4500 Myr the earth's been around - so making life is probably pretty easy. It took 4000 Myr to make multicellular life, so that's a lot more difficult. And it took almost 4500 Myr to get intelligent life, so that's even tougher (although maybe not too difficult once you get higher lifeforms). But, 4500 Myr is about half the lifetime of the Sun, so intelligent life has tops 10000 Myr to evolve and seems to need at least half of that. (Obviously these arguments are based on a sample of one, so are a bit dodgy).

Plus, it looks like for stars to have planets they need to have quite alot of heavy elements. For its age, the sun has a lot of heavy elements which mean it could be one of the oldest stars to have planets. This might not mean intelligence is rare to develop, but that we could be the first.

Simon

 

[Frostbite]

What does "smart" mean in this context? I can make a pretty strong case that octopi aren't as smart as most mammals, or even many birds. I have an easier time demonstrating they're not as smart as humans.

...

That goes without saying now don't it?

 

[Frostbite]

Jupiter being the comet hoover makes sense, tho it assumes that other star systems have a lot of comets in them. The Solar System seems very battered... all planets have at least some sort of sign showing that it's been pummeled with space debris, and we have countless pebbles going around the Sun - remains from a cataclysmic past. I doubt that we get comets from outside the Solar System.

I'm no astronomer, but I think I can imagine a star system which would evolve with less violence. But now, we can speculate that the Earth's relatively violent past is actually an motivator for evolution. It took the Earth 100Myr to have life, and 4000Myr to have multicellular life, but how many times did that process had to restart from scratch following an environmental change on a planetary scale?

 

[simong]

> around the Sun - remains from a cataclysmic past. I doubt that we
> get comets from outside the Solar System.

Most of the comets come from the Oort cloud which is way-out beyond the orbit of Pluto. Its thought to be where a lot of the icy debris from the planet formation process is hanging-around. The Shoemaker-Levey imapct on Jupiter a few years ago was a classic example of how Jupiter is thought to clear-up the rubbish streaming in from the outer solar system.

> I'm no astronomer, but I think I can imagine a star system which would
> evolve with less violence.

Probably not, it looks like planets have to form from the bottom-up, from dust to asteroids, to planets which means a lot of rubbish should be left-over whenever you form planets.

> It took the Earth 100Myr to have life, and 4000Myr to have multicellular
> life, but how many times did that process had to restart from scratch
> following an environmental change on a planetary scale?

Its speculated that maybe life got started several times and then got wiped-out by a major impact and had to restart. We'll never know if this is true, but it might be.

There have been several mass extinction events (the dinosaur one being the most famous). The biggy about 400 Myr ago killed-off over 90% of species. We probably wouldn't be the intelligent (?) species if the dinosaurs hadn't got wiped-out, but one of them could well have made it.

I'm not an evolutionary biologist (I come at this as an astronomer), but as far as I know climate change is thought to have been a driver towards intelligence. Monkeys had to get smarter to cope with the forests they lived-in dissapearing. But I think *major* climate change would kill-off many advanced species.

Simon