Don’t talk to aliens, warns Stephen Hawking

[dan2100]

I think I addressed that in my post to Christopher somewhat. If you are asking is it possible that scientists could evolve from bird-like animals then my answer would be yes, BUT, there wings would have to morph into arms and they would have to evolve fingers to make tools etc. etc.

I'm not sure what would be reused were something bird-like to become more of a tool-using animal than currently. As you're probably aware, birds do use tools. Aside from the more stunning recent findings of tool-making and use in crows, many birds already build nests, which involves gathering materials and, often refashioning them to build a complicated structure. This is done, in examples I've seen, mostly using the beak with the claws usually being used merely to hold and transport rather than pick or reshape. Were I to speculate on further refinements of this, I imagine that the wings would NOT "morph into arms." I think the likely path might be more along the lines of the beak evolving further and maybe better coordination with the legs and claws. This might leverage, in some birds, a very flexible kneck (compared with humans, that is).

But this is just my guess. It's not meant so much as a knockdown proof of how evolution of bird-like animals toward technological civilization will actually take place, but more to show that your view seems wanting. In other words, I don't expect ET to have hands and look basically human -- even if they might be covered in feathers.

I ask you the same thing I asked Christopher - what do you think lead to the evolution of the highly specialized human nervous system?

I'm not exactly sure and the jury's still out on this one. (Of course, in science, one might say any jury ruling is always provisional.) I'm aware of a few different theories, including a coevolution of tool-use and brain. The problem with the simple version of that theory, though, is that tool-use, as has been recognized, is fairly widespread among animals. It seems to me that the older view used to be that using tools is what made humans special, but that came under attack as more and more evidence for not just tool use but pretty sophisticated tool use -- like crows refashioning wire to use as tools (the more complicated use involves not just taking something to use as a tool, but reworking it to be better at being that tool). Of course, other factors might enter into the picture, such as the basic body plan making it hard for more encephalization. (In the crow example, a limiting factor might be that crows need to fly, especially since they face ground predators.)

[Christopher]

Well why haven't dolphins and primates evolved the specialized brain tissue that we humans have? What have we done that encouraged this to evolve?

Could be simply a matter of time in the evolution of dolphins. It was a matter of time with primates. Using one datum in such a complex system is reductionistic, and we should absolutely be including potentials. That, and I'm using my evolved imagination to picture other species, so my primate evolution contributes directly to the possibility of other developments. Take that!

Edited May 4, 2010 by Christopher

[dan2100]

Well why haven't dolphins and primates evolved the specialized brain tissue that we humans have? What have we done that encouraged this to evolve?

Could be simply a matter of time in the evolution of dolphins. It was a matter of time with primates. Using one datum in such a complex system is reductionistic, and we should absolutely be including potentials. That, and I'm using my evolved imagination to picture other species, so my primate evolution contributes directly to the possibility of other developments. Take that!

Yes, remember this is not so much a discussion of why humans evolved, but what might happen on other worlds in terms of evolving technological civilizations.

Also, my understanding is dolphins do have large cortexes (cortices?) -- comparable to humans. I don't have a reference for this, but will see if I can find one in coming days.

[dan2100]

Also, my understanding is dolphins do have large cortexes (cortices?) -- comparable to humans. I don't have a reference for this, but will see if I can find one in coming days.

See, e.g., http://en.wikipedia.org/wiki/Bottlenose_dolphin#Intelligence

Also, given there is something I'd forgotten: tool use in dolphins. Granted, it's nothing like the fine motor control GS believes is central.

[tjohnson]

I honestly don't know what we are arguing about anymore. Suffice it to say that I believe the idea of convergent evolution has merit and I think it applies to evolution of planets and ecosystems as well. Of course we can't verify this until we actually get to a planet (or they get here ) and see for ourselves.

[dan2100]

I honestly don't know what we are arguing about anymore. Suffice it to say that I believe the idea of convergent evolution has merit and I think it applies to evolution of planets and ecosystems as well.

But what does it mean in this context? You're making rather narrow guesses, here, about what ET would be like -- e.g., ET's will have hands and brains basically like human ones. Even looking at examples of convergent evolution on Earth -- e.g., the similarities between body shapes in sharks, ichthyosaurs, and dolphins or between wings in pterosaurs, birds, and bats or even between eyes in vertebrates, cephalapods, and box jellyfish (all have similar camera-like eyes, but the last doesn't even have a true brain!) -- should throw some cold water on some speculations. (That doesn't mean such speculations are wrong, but they're not based on familiarity with actual convergent evolution.)

Of course we can't verify this until we actually get to a planet (or they get here ) and see for ourselves.

Naturally, more data are needed. My guess is when such data are forthcoming -- humans meet ET -- then there will be many surprises. My guess is, too, even just discovering life off world -- life that doesn't seem related to Earth life -- will also surprise many. I think it'll wreck many a theory and speculation.

[BaalChatzaf]

http://www.timesonli...icle7107207.ece

This seems to presume Earth has loads of goodies that can't be had so many other places in the universe -- many such places likely being much closer to home.

I am looking forward to the day when we will meet a race of aliens that think our garbage is a gourmet meal and who pee out gasoline. Talk about an encounter made in heaven.

Ba'al Chatzaf

[dan2100]

http://www.timesonli...icle7107207.ece

This seems to presume Earth has loads of goodies that can't be had so many other places in the universe -- many such places likely being much closer to home.

I am looking forward to the day when we will meet a race of aliens that think our garbage is a gourmet meal and who pee out gasoline. Talk about an encounter made in heaven.

Ba'al Chatzaf

Have you tried holding your breath?

[sbeaulieu]

http://www.timesonli...icle7107207.ece

This seems to presume Earth has loads of goodies that can't be had so many other places in the universe -- many such places likely being much closer to home.

I am looking forward to the day when we will meet a race of aliens that think our garbage is a gourmet meal and who pee out gasoline. Talk about an encounter made in heaven.

Ba'al Chatzaf

Awesome! Symbiotic relationship in the making? I just hope they're tall enough to make it to the gas cap

~ Shane

Edited May 7, 2010 by sbeaulieu

[dan2100]

There's a reason humans don't have close intellectual relatives today (though humans co-existed with such species in the past)- they were likely wiped out by us. So I wonder what evidence there is to support the idea that any species which evolves to technologically-advanced degrees would be necessarily hostile.

I'm not sure there's much if any evidence that humans "likely wiped out" "close intellectual relatives." It seems much more likely that humans won out simply because their "close intellectual relatives" lost habitat and humans were just lucky to be adapted to habitats that either expanded or weren't as minimized. Think of Neanderthals. They were likely adapted to the forest habitats of Europe and the Near East. As the last ice age progressed, these likely shrunk to the point where Neanderthals simply died out -- died out long and were not wiped out by others humans.

Of course, sticking to this example, one could say there's not enough evidence to support this view, but I believe there's some evidence to support while the genocide view seems to be backed by no evidence -- no examples, for instance, of Neanderthals that have been killed by human weapons and almost no evidence that humans and Neanderthals even lived in the same places at the same time.

There is some decent evidence, on the other hand, of humans fighting each other. War Before Civilization: The Myth of the Peaceful Savage by Lawrence H. Keeley is probably the locus classicus for this.

I want to amend this view in light of a recent report. There is some genetic evidence now for Human-Neanderthal interaction. However, still no evidence I've seen for Humans wiping out Neaderthals. The genetic evidence seems to be that there was some Human-Neaderthal interbreeding and this was likely localized to the Middle East. This is not enough, at this point, to determine why Neanderthals, on the whole, died out and there's no evidence, from my reading of interaction or interbreeding in Europe.

The report is here http://www.sciencemag.org/cgi/content/abstract/328/5979/710

Edited May 13, 2010 by Dan Ust