have they found anything?

[amb]

Sigh. Nice try, but you know full well by now that I'm not claiming that any other animal would "take over the civilization duties" (whatever that means).

You are wrong when you claim that it is impossible for human-like intelligence to evolve in any other species.



Again, if humans went extinct (and somehow magically left all other living species alive), then immediately another species would be the most intelligent animal.

I'm not sure what you mean by "replace" us, but I do think the ecological niche we vacated would be filled by other animals. (Again, with the caveat that I don't see this hypothetical ever happening where Homo sapiens goes extinct but chimpanzees do not. In fact, I think the reverse is much more likely to happen in the real world where there are nearly 7 billion of us and just a couple hundred thousand of them at the most.)

If the Giraffa camelopardalis species went extinct tomorrow, some other animal would then become the tallest animal in the world (and some other animal would be the new largest ruminant), and it would be wrong to claim that "giraffe-like" height would be impossible ever to evolved again in another species.

But you have just agreed with me without realizing it.
If we 'magically' were to become extinct, it would mean the end of civilization. Sure all other animals, or the next intelligent creature down from us would take over as the next more smarter species, but it's not capable of building a satellite, computer etc.

 

[amb]

Did anyone watch "Becoming Human" last night on Nova? One thing that struck me as being pertinent to this discussion:

Apparently the rapid changes in environment in the rift valley region was a significant contributing factor to the development of our intelligence. In other words, my counter argument to the rare earth hypothesis, it may seem that the moon and our stable rotation and protection from meteor impacts may actually have impeded the evolution of intelligence on this planet...

Just saying.

That's arguable. If the asteroid that wiped out the dinosaurs had not struck the Earth when it did, perhaps they would still be around in some form. I know that birds are the descendants, but perhaps they would still be gigantic in size and impeded homo sapiens from evolving.

 

[JoeTheJuggler]

That's arguable. If the asteroid that wiped out the dinosaurs had not struck the Earth when it did, perhaps they would still be around in some form. I know that birds are the descendants, but perhaps they would still be gigantic in size and impeded homo sapiens from evolving.

Or it could be that if an asteroid had struck a million or ten years earlier that humans might have evolved sooner.

This is the point I raised when I first gave a summary of Darling's book. The Rare Earth hypothesis basically says that for complex life to evolve, every little thing about the Earth must be in place and regarded as friendly to life. At the same time, it seems that trauma is what drives big changes in evolution. (The Cambrian explosion can be seen as the result of the poisoning of the atmosphere with too much oxygen pollution.) It's basically the idea of punctuated equilibrium.

As I've said before, we don't know that hitting the ecological "reset" button more frequently might not result in more complex forms (including greater intelligence) arising sooner. The Earth might be too friendly for that, and what took billions of years here might happen more quickly elsewhere. (I'm not asserting it's so, only that it's just as valid to speculate this as to make the speculations made in the Rare Earth hypothesis.)

 

[JoeTheJuggler]

But you have just agreed with me without realizing it.
If we 'magically' were to become extinct, it would mean the end of civilization. Sure all other animals, or the next intelligent creature down from us would take over as the next more smarter species, but it's not capable of building a satellite, computer etc.

Yes, I agree that if human civlization were wiped out it would be the end of human civilization. But that's just a trivial observation.

I disagree with you that it would be impossible for another intelligent civilization to develop ever again, which is what you've asserted several times.

 

[amb]

We only have one example to study, and that example has shown that only one species out of literally billions of life forms that have ever lived here on this one example have had the intelligence enough to produce a civilization. And this going over old ground.
Also, extinction seems to be the norm/rule. Survival is the exception. We may not survive until the time it takes to develop interstellar craft that can reach at least 10% of the speed of light. It seems that traveling to another star system is just a pipe dream unless we can survive at least another 100.000 years intact. This is why I suspect we haven't been visited yet by a much older alien civilization. A technological civilization usually blow themselves up before they achieve interstellar travel. Or perhaps their world is struck by a huge asteroid ending all complex life as our will be one day.

 

[Roboramma]

amb, if the blue whale went extinct, would it be impossible for a larger animal to evolve in the future?

 

[JoeTheJuggler]

We only have one example to study, and that example has shown that only one species out of literally billions of life forms that have ever lived here on this one example have had the intelligence enough to produce a civilization. And this going over old ground.

How exactly do you define civilization? How do you know only one species has ever had intelligence enough to produce one?

Yes, this is going over old ground.

And since you're repeating yourself, I'll repeat that intelligence is not unique to humans and exists (and has existed) as a continuum among many species on Earth.

Also, if you mean to change Earth from a 1 for 1 data point to a 1 for a few billion (in say technology capable of sending and receiving radio signals) that's fine, but it doesn't help your case that intelligent life in the galaxy is necessarily limited to us. In other words, if you count Earth as 1: 3 billion, then you have to treat the same ratio in the galaxy as

number of human-like intelligent species in the galaxy: the total number of species (rather than life-bearing planets) in the galaxy

It doesn't help your argument to make the second value greater.

 

[JoeTheJuggler]

We may not survive until the time it takes to develop interstellar craft that can reach at least 10% of the speed of light. It seems that traveling to another star system is just a pipe dream unless we can survive at least another 100.000 years intact. This is why I suspect we haven't been visited yet by a much older alien civilization. A technological civilization usually blow themselves up before they achieve interstellar travel. Or perhaps their world is struck by a huge asteroid ending all complex life as our will be one day.

Funny, those sound exactly like some of the the points I listed by number to refute your argument based on Fermi's Paradox.

Since we can't expect evidence of an intelligent civilization to be ubiquitous in the galaxy, the lack of that evidence doesn't argue that such civilizations don't exist.

Or, as I said very early, it could be that there could be hundreds or thousands of radio-technology-using intelligent civilizations in the galaxy but since things are so spread out in space and time we may still never run across them.

I agree that this is probably the reason why we haven't been visited by another civilization rather than the conclusion given by the Rare Earth hypothesis that we are so rare as to be certainly unique in the galaxy.

 

[amb]

amb, if the blue whale went extinct, would it be impossible for a larger animal to evolve in the future?

The blue whale has been here for millions of years. It has come close to been made extinct by man's greed. But no. To your question. If you think otherwise, which of the present marine creatures do you think could take it's place, even given another million years.

 

[Roboramma]

The blue whale has been here for millions of years. It has come close to been made extinct by man's greed. But no. To your question. If you think otherwise, which of the present marine creatures do you think could take it's place, even given another million years.

Any of the baleen whales could evolve to fill the same niche. You will note that I said could, and of course it may take more than a million years, it may take tens of millions of years.

It may be a penguin that turns out to evolve to a life completely in the water, and much larger even than the blue whale.

The whale shark is a pretty big fish which, unless I'm mistaken, also fills a similar niche to the blue whale. Similar pressures could cause it to evolve to be bigger as well.

Of course, it's possible that if the blue whale goes extinct, nothing will ever evolve to be larger than it. But there's also nothing stopping it from happening, and there are certainly selection pressures toward larger size, so it's not particularly unlikely that it could happen in the future.

I actually hadn't even imagined that you would make that answer, it's just so incomprehensible to me that someone could think it's impossible for something which already happened to happen again.

 

[amb]

Do you ever consider the tape of Earths history been re-played again from day zero.
And if you did, do you understand the trillion to one chance that homo sapiens would evolve to be exactly the same as we are today? That goes for every form of life that's ever lived on this planet, none would be the same again. We would not recognize it if we were to be a spectator.

Happy birthday. May you have many, many more.

 

[LarianLeQuella]

Do you ever consider the tape of Earths history been re-played again from day zero.

STOP WITH THAT FARKING RED HERRING!!!!!!!!!!

Seriously dude, that is the downright most assenine and even stupid argument I have ever hear presented by anyone who would even consider Sagan a person of note, let alone a here of any sort (which you have said). That is not in the slightest at all, or even remotely what we are saying. You keep bringing this up, and all we can coclude is that you have absolutely zero understanding of evolution, and what it is we are trying to say. That stupid statement makes me want to apply a car battery to your genitalia and shock you ever time you write it. Seriosuly, stop it!

 

[JoeTheJuggler]

Do you ever consider the tape of Earths history been re-played again from day zero.
And if you did, do you understand the trillion to one chance that homo sapiens would evolve to be exactly the same as we are today? That goes for every form of life that's ever lived on this planet, none would be the same again. We would not recognize it if we were to be a spectator.

Yeah, this is getting old, amb. I've already told you that the search for ETIs is not the search for ET Homo sapiens. Nobody thinks it's likely that we'll find a species identical to Homo sapiens "out there". Or that the evolution of Homo sapiens was pre-ordained somehow.

Now, the odds of life intelligent life evolving if you re-ran the history of Earth? Or the probability of an ET intelligent civilization? Who knows?

Those who think convergence explains a lot of evolution would say it might be inevitable, or very nearly so.

Of course the fact is we don't know, and where most of us disagree with you is in your claim to know (that is your claim that another species evolving human-like intelligence is impossible).

 

[JoeTheJuggler]

I actually hadn't even imagined that you would make that answer, it's just so incomprehensible to me that someone could think it's impossible for something which already happened to happen again.

And that is the central point he is making about ETIs. That even though it happened here on Earth, he insists that it's impossible to happen elsewhere.

 

[JoeTheJuggler]

The blue whale has been here for millions of years. It has come close to been made extinct by man's greed. But no. To your question. If you think otherwise, which of the present marine creatures do you think could take it's [sic] place, even given another million years.

I'll answer your question if you'll answer mine.

My answer to your question: any species can evolve to be the size of the blue whale given enough time.

Why do you think it is impossible for any species to evolve to this size?

 

[dallasroofer]

I suppose we could debate this all day long. To quote the great Carl Sagan:

"But the fact that some geniuses were laughed at does not imply that all who are laughed at are geniuses. They laughed at Columbus, they laughed at Fulton, they laughed at the Wright Brothers. But they also laughed at Bozo the Clown."

But I say, who's to say (including Sagan) that Sagan wasn't a genius as well. Like Achilles he will be remembered.

 

[dallasroofer]

I define it by using things like money, language, and the creation of the arts & humanities. I would also single out morality as a not entirely unique trait of human civilization, but we care more about morality than say a snow leapord eating an impala.

 

[Roboramma]

For amb:

http://en.wikipedia.org/wiki/List_of_examples_of_convergent_evolution

 

[amb]

Happy birthday Carl Sagan. He would have been 75 today. We lost a genius much to early.

RIP.

Roboramma, I know all that.

 

[Roboramma]

Roboramma, I know all that.

Okay, so...

If you understand convergent evolution, and the fact that the same traits evolve multiple times in completely separate lineages then what, again, was it that makes you think it's impossible for the same trait to evolve multiple times?