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have they found anything?

So you are saying that if and when we encounter ET he will look something like homo sapiens?
Methinks not. Another planet, or right here on Earth the random events that caused us to evolve to what we are would be different if a cosmic ray would strike a chromosome, producing a mutation in the hereditary material, you might wind up with intelligent beings after some billions of years. You might wind up with creatures of high ethical and artistic or even theological accomplishment. BUT they would not look anything like human beings. We are the products of a unique evolutionary sequence. Elsewhere, different environment, different necessity to adapt to changing conditions, a different sequence of random events, including random genetic events, and we should not expect anything like a human being.
 
amb said:
So you are saying that if and when we encounter ET he will look something like homo sapiens?
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Nobody's saying that. In fact, you're the one saying that if you ran evolution over again on Earth we'd be unlikely to come up with Homo sapiens again, and this fact is somehow proof that ET intelligence could not exist. I've been pointing out that the search for ET intelligence is not the search for ET Homo sapiens.

However, intelligence just might be one of those traits that is so successful that evolution converges on it. (As has been pointed out, humans are not the only species on the Earth with this trait. As with a trait like "height", intelligence exists as a continuum among many species.)

Also, no one here is claiming that human-like intelligence or blue whale-like size, or giraffe-like height would necessarily evolve again.

We just reject your claim that it's impossible.

You've read the article on convergent evolution with plenty of examples of traits that have evolved independently, yet you still claim that a trait (or rather a degree of a trait) that evolved once can never evolve again. Either you still don't understand what convergent evolution is, or you don't really mean it when you say it's impossible for these things to evolve again, or you are living with cognitive dissonance.
 
Going back just a bit. . .

amb said:
The planet is over populated already. In that case sending humans into space in search of other worlds to populate becomes imperative. I believe that may be the future. Life somehow started here on the Earth and is destined to populate the universe. I know the word ''destined'' has connotations of ID.
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Yes, "destined" does suggest that you think the future is predetermined somehow, and really points to belief in a supernatural or metaphysical theory.

We could become extinct within say, a century or two, and all this will never happen. There's your Fermi's Paradox.
The universe is just too big. We are alone as far as homo sapiens is concerned.
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We might be approaching agreement. You will note that I've said all along that the universe is really big, and stuff is so spread out in space and time that I don't think humans will ever encounter another intelligent civilization. (Really, check out my very first post in this thread.)

But you were claiming that they don't exist. Now you're using a sort of intermediate wording between what I said and what you've been saying.

When you say, "We are alone as far as homo sapiens is concerned" does that mean what I said? Do you admit that there could be dozens or hundreds or even thousands of civilizations like our own in the galaxy and we'd never see evidence of any of them, or do you mean that it's impossible that another intelligent civilization exists in the galaxy?

Your hypothetical of what would happen if humans alone went extinct (your claim that it would be impossible for any other species to evolve human-like intelligence) makes me think you're still saying it's impossible that other ET intelligent civilizations exist, rather than the statement that they might exist even if we never find evidence of their existence.
 
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amb said:
So you are saying that if and when we encounter ET he will look something like homo sapiens?
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Actually that's basically the opposite of what I'm saying. That is what you, only a few posts ago, implied: that intelligent ETs would have to be so similar to us as to be impossible.

I am pointing out that particular traits are adaptive, and those adaptive traits (intelligence included) are selected for in a way that is non-random. So to encounter another life-form that was very different from us in many ways, but also happened to be intelligent would not be as astounding as you think. No more astounding that encountering another life-form that, in spite of many differences, also had eyes.

Is there any reason to believe that intelligence is an adaptive trait that evolution may converge upon in separate lineages? Yes, because it has done so numerous times on earth.

For instance, the common ancestor we share with crows was much less intelligent than a crow. Thus, the crow has independently evolved greater intelligence.
The same is true of whales.
It's also true of squids and their close relatives.
And a great deal more life on earth.

How did that happen?
 
amb said:
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.
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By the way, in regards to other species evolving toward the size of the blue whale in the future:
Cope's rule states that population lineages tend to increase in body size over evolutionary time.[1] While the rule has been demonstrated in many instances, it does not hold true at all taxonomic levels, or in all clades.
Larger body size is associated with increased fitness for a number of reasons, although there are also some disadvantages - both on an individual level, and on a clade level: clades comprising larger individuals are more prone to extinction, which may act to limit the maximum size of organisms that have been observed.
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http://en.wikipedia.org/wiki/Cope's_rule

Of course, as you will read on the wiki page, cope's rule is by no means hard and fast. There are plenty of exceptions, in which things evolve toward smaller size, or stay the same size for longer periods. There are plenty of selection pressures beyond those that favour larger size, including some that favour smaller size.

Similar things can be said of intelligence that can be said of body size. And because of that, it's certainly not impossible for intelligence to continue to increase in other lineages than our own.
 
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And Gould's essay does nothing to support your assertion that a trait (or degree of a trait) that has evolved once is impossible to evolve again.

This essay mostly says that the history of evolution is unpredictable. That would support the point you've made that we all agree with that we are highly unlikely to find Homo sapiens "out there", or that if we re-ran evolution on Earth that we would end up with Homo sapiens.

This essay looks like something he wrote while he was working on The Full House. Makes a lot of the same points--including the point that a human-centric view of the history of evolution distorts the way we frequently think of it (and especially the way we teach it).

According to Gould, there was no "Age of Dinosaurs" or "Age of Reptiles" or "Age of Humans". If anything, from nearly the beginning we have been in the "Age of Archaebacteria". The history of evolution is not well-represented by a "ladder of life" going straight to humans. Instead it's a great bushy structure with a left wall of simplicity.

(ETA: In the Full House, IIRC, he uses the evolution of the horse as an example. It's often taught that there is a clear one-way trend in a number of traits such as body size and number of toes going from eohippus to the modern horse. But that's oversimplified to the point of being erroneous. The same of course is true of intelligence, even if we only look within primates.)

He also makes the case for punctuated equilibrium. This notion (that environmental trauma is what spurs change) goes against the arguments for a "friendly" environment made in Rare Earth, and seems to be a more accurate view of the history of evolution.
 
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amb said:
So you are saying that if and when we encounter ET he will look something like homo sapiens?
Methinks not. Another planet, or right here on Earth the random events that caused us to evolve to what we are would be different if a cosmic ray would strike a chromosome, producing a mutation in the hereditary material, you might wind up with intelligent beings after some billions of years. You might wind up with creatures of high ethical and artistic or even theological accomplishment. BUT they would not look anything like human beings. We are the products of a unique evolutionary sequence. Elsewhere, different environment, different necessity to adapt to changing conditions, a different sequence of random events, including random genetic events, and we should not expect anything like a human being.
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I was watching the science channel and there was a discussion on what to expect if we evr encountered intelligent life on another planet. The program said that while humans and the extraterrestrials would in no way resemble each other both the intelligent aliens and humans would recognise each other for fellow intelligent beings almost immediately.
 
Cainkane1 said:
I was always taught that the genetic dice never fall the same way. Once a creature went extinct it was gone forever.
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But of course the extinction of a species doesn't mean that none of the traits of that species will ever be seen again. (Amb is arguing that if the tallest giraffe species went extinct, it would be impossible for any other species to evolve that degree of height. He says that if humans went extinct it would be impossible for human-like intelligence ever to evolve again.)

If that were so, we'd quickly run out of traits, and the number of now extinct species would require the extinction of all extant species.

Another example of a trait that evolution has converged on again and again is the saber tooth in various tetrapod predators. All of them are currently extinct, but the trait arises again and again. There is no reason to think it will never happen again.
 
Thanks for spelling that out Joe, I was sort of lacking in patience. I think between us we've made the same point about twenty times in this thread.
 
Roboramma said:
Do you really consider that to be a response to the post?
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Excuse me if I don't go into the finer detail and post a half page of what you already know. :p I'm constrained by time, unlike some who can sit at their keyboard for a whole day. :)
 
So, one day I may have a beer with ET? Of course intelligent beings would imitatively recognize each other intelligently. But physically it would be like a mullet meeting a lion.
Anyway, it's pure science fiction not speculation of humans ever meeting face to face an alien race. Radio signals is the only way it will ever happen. We have had Television since the late 1940s. That means our signals have had time to travel 64 light years away. If the galaxy was teeming with intelligent life as some postulate, surely some intelligence would have had time to respond to say; ''I Love Lucyshow. This tells us there is no human like intelligence in the immediate vicinity say 10-30 light years that use radio astronomy, the only form of searching the cosmos for signs of life.
 
amb said:
Excuse me if I don't go into the finer detail and post a half page of what you already know. :p
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Well, I'm also quite happy that you don't post half a page of what I already know. But since you've repeatedly made the same assertion and yet have so far not once responded in any meaningful way to either Joe or I making rebuttal to that point, I have to say it seems more like you don't have a response, rather than that you simply don't want to make it.
 
amb said:
Anyway, it's pure science fiction not speculation of humans ever meeting face to face an alien race. Radio signals is the only way it will ever happen. We have had Television since the late 1940s. That means our signals have had time to travel 64 light years away. If the galaxy was teeming with intelligent life as some postulate, surely some intelligence would have had time to respond to say; ''I Love Lucyshow. This tells us there is no human like intelligence in the immediate vicinity say 10-30 light years that use radio astronomy, the only form of searching the cosmos for signs of life.
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No, this tells us that no intelligent life in the immediate vincinity is engaging in a comprehensive enough search to have noticed our TV broadcasts, and also wants to send a message back in response.
Unless of course we missed the message.

Which seems to me to say very little.

I agree with you, though, about the fact that it's pretty unlikely that we'll ever come face to face with ET.
 
Roboramma said:
For instance, the common ancestor we share with crows was much less intelligent than a crow. Thus, the crow has independently evolved greater intelligence.
The same is true of whales.
It's also true of squids and their close relatives.
And a great deal more life on earth.

How did that happen?
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amb said:
Through adaption, how else?
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Of course your answer contradicts your repeated assertion that it's impossible for another species to evolve a given level of intelligence. (This stuff you keep saying about how if humans went extinct it would be impossible for any other species ever to evolve human-level intellgence.)
 
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