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Proposed: intelligent, technology-using aliens look pretty much like us due to evolutionary convergence


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Initial post: Jul 25, 2012 4:02:00 AM PDT
Ehkzu says:
The lay public has been bamboozled by Hollywood's special effects guys and CGI mavens. Even though life comes in amazing varieties, the exigencies of evolving an intelligent tool-user (not twigs to probe for termites--I mean 12mm spanners and MRI machines) mandate an evolutionary model that produces us.

Can't be either proven or disproven conclusively, but I'm amused by how aliens being really different has become such an article of faith that we scoff at all those babe-o-licious green-skinned chicks that always fall for Captain Kirk.

I don't think they all speak colloquial Southern Californian English, like all of Star Trek's aliens did; just that they look like us.

Yet another place where I'm doomed to be Mr. Buzzkill. The Star Wars Cantina is totally bogus.

The real aliens resemble us for the same reason that ichthysaurs, sharks, swordfish and dolphins all resemble each other.

In reply to an earlier post on Jul 25, 2012 6:49:16 AM PDT
Last edited by the author on Jul 25, 2012 6:56:57 AM PDT
Interesting thought, Ehkzu. But note that hydrodynamics is both a very demanding selective condition and also one with only a single solution. In that respect, it's not typical. Evolution has often responded to a single challenge in multiple ways.

Also, if I can assume you're talking about intelligent aliens, what do you say to the argument that intelligence is a trait that can be overlaid on many different body types? For example, for 97% of the last 75 million years, our lineage has been arboreal. But that doesn't matter anymore. The only anatomical features we might assume most intelligent species will have are sufficient dexterity to manipulate tools and some means of complex intraspecies communication. Neither of those must take a specific physical form, in contrast to how we can assume that most marine predators will be fast swimmers and thus have a fusiform shape. If humans die out, my money's on elephants getting even smarter. If that were to happen, I suppose they'd look about as different from us as those critters in the Cantina.

In reply to an earlier post on Jul 25, 2012 9:02:13 AM PDT
nah

they are shorter
with squinty eyes
and virtually no nose
and pear shaped heads

In reply to an earlier post on Jul 25, 2012 9:45:01 AM PDT
Last edited by the author on Jul 25, 2012 9:46:13 AM PDT
Ehkzu says:
Y, my comparison with the stringent requirements of marine pelagic predators was intentional, in part because I'm an experienced scuba diver. Note that even under those stringent hydrodynamic rules we get tails moving sy 90 degree angles to each other across these organisms. Cetaceans may have needed horizontal flukes due to their spending so much time at the surface (I get this from my own experiences finning at the surface), but since ichthysaurs had similar requirements it seems like the tailplane orientation is optional.

Likewise the shape of the forepart of the body ahead of the widest point allows for more variation than the aft part. Hence mahi-mahis, for example.

Now consider us. Remember that by "tool using" I mean possessing real technology. Right off the bat that makes 'em terrestrial. Can't smelt iron underwater. It also makes their ancestors quadrapeds, Avatar notwithstanding, because hexapeds and up would have been outcompeted and true bipeds (no arms at all) wouldn't have been able to pick up a tool and walk at the same time. You couldn't have gotten here from there.

They'd also need stereo vision for proper tool using, which requires ancestors being arboreal and/or carnivorous predators. Then, whatever the exact evolutionary route, their ancestors would have to stand up and start walking. And as you know, our feet--and legs, and, most importantly, our pelvises--were made for walking; specifically, inverse brachiation--and that's just what they do. Then the forepaws have to become hands, not just with an opposable thumb, but with our little finger able to interact with that opposable thumb to grip tools precisely.

One possible variation you mentioned was something from elephantoids. This was explored in a hard sci-fi novel, actually: Footfall. But even if you gave one a nose like a star mole, I don't think a single trunk, no matter how versatile as trunks go, is going to get you there. You need two arms, not one, and they need either an endo- or exo- skeleton. And the sheer bulk of an elephant severely limits versatile habitat occupation. I wouldn't rule it out categorically but I think it's far less plausible than an evolutionary model leading to an erect bipedal hominid.

With a head like ours. Sense organs have to be as near the brain as possible, and the brain's going to be at the anterior end of the creature--that should be obvious from looking across all the phyla with central nervous systems. So you get a hominid head, with stereo vision, reduced nose, ears on the side for stereo hearing, reduced jaw from adoption of cooking...

You get us. I'm not short on imagination, asd as a diver I've seen a mindblowing diversity of lifeforms, from pleurobranchs to cuttlefish, to name just two. I understand how we don't want to seem unimaginative. It's a mark of intelligence, and all those scifi films that just assume aliens look like us except for forehead prosthetics--well, it seems cheesy, doesn't it?

But however I try to wriggle out of it and ponder intelligent gasbag critters floating in some strange planet's stratosphere, I have to remember the great scientific principles not just of convergent evolution, but also of the Assumption of Mediocrity. And I wind up looking in a mirror disgruntledly.

In reply to an earlier post on Jul 25, 2012 9:48:23 AM PDT
Last edited by the author on Jul 25, 2012 9:51:19 AM PDT
Ehkzu says:
"They got little hands
Little eyes
They walk around
Tellin' great big lies
They got little noses
And tiny little teeth
They wear platform shoes
On their nasty little feet "

http://www.youtube.com/watch?v=TUXD3kjI_PI

In reply to an earlier post on Jul 25, 2012 10:01:17 AM PDT
M. Helsdon says:
"And I wind up looking in a mirror disgruntledly."

If you factor in alien environments, you'll get different results.

Increase gravity, and a hexapod looks more efficient, increase atmospheric pressure, and under some conditions, sonar may be more efficient than sight; alter temperature and different body shapes become more efficient.

You seem to be attempting to rerun the evolution of intelligence in what is basically a terrestrial environment, and even in a terrestrial environment there are significantly different bodies hosting relatively high animal intelligence. The fact is, then even when exoplanets roughly the size of Earth in terms of mass and radious are found, they are unlikely to be very Earth-like. Earth itself has been a very different place during its four and half billion years.

If intelligence had arisen from an intelligent dinosaur, it might have been a biped, with two arms and two hands, but it would probably also have had a tail and not stood upright; just scale up a velociraptor or a similar species, and you get a creature that is similar but dissimilar to us.

Posted on Jul 25, 2012 10:12:53 AM PDT
Last edited by the author on Jul 25, 2012 11:40:18 AM PDT
Rev. Otter says:
+1, but only for the green-skinned alien babes.

In reply to an earlier post on Jul 25, 2012 12:29:25 PM PDT
Ehkzu says:
I've considered all these things, MH, in part due to having read thousands of scifi novels as a kid, such as Hal Clement's Mission of Gravity (SF Collector's Edition) (Gollancz Sf Collector Editions), which posits a much bigger planet whose intelligent indigenes were like biggish millipedes, because our body form would result in death if we tripped, or such as Dragon's Egg/Starquake: 2-in-1 (Two Novels in One), which posits grain of rice-sized intelligent beings living exponentially faster than us on the hard surface of a neutron star (the author is an astronomer specializing in neutron stars). The Mote in God's Eye in which a race artificially evolved itself into specialized subtypes...I could go on.

But.

First of all, we can't be sure advanced life can develop on anything but an Earth-scale planet with a large captive Moon like we have. Remember, I wasn't even talking about intelligent life--I was talking about iron-smelting, tool-using life. That leaves out marine environments anywhere, courtesy of the laws of physics. Has to be terrestrial. Dolphins are cool and have brains as good as ours, but they can't grasp things, they can't smelt--and much of their impressive brainpower is occupied by sonar processing, courtesy of their descent from river otterlike amphibious mammals adapting to turbid water conditions. So though they pass the mirror "hey that's me" test--as do elephants, it turns out--they aren't remotely smart enough to qualify for what I'm talking about.

Could that land be the terrestrial environment of a much bigger high-G planet that made, say, hexapedism superior to quadrapedality? The science book Rare Earth: Why Complex Life Is Uncommon in the Universe--a real buzzkill BTW--convinced me that the "window conditions" for a planet with intelligent life are waaay narrower than I'd imagined. For example, the need for a big Moon, for two reasons: (s) axial stabilization and (b) the collision forming the moon also blowing off our excess water, enabling us to have landforms as well as mineral mixing.

We also need a hot metallic core without which no Van Allen belt and the Sun microwaves us permanently.

So...maybe a much bigger planet is less likely to have the requisite big moon, in which case the advantages of hexapeds are moot.

Astronomers have discovered a number of Life Zone (liquid water) planets that are apparently around 2-3-5 times Earth size, covered with water, no land, and hot ice below the liquid water preventing mineral transfers from the land trapped beneath. So the only mineral input would be from the odd meteorite/asteroid.

Probably no life of any sort on such planets, or at best microbial life hanging by a thread in a nutrient-starved environment.

So I agree that most exoplanets won't be Earth-like. I contend that most will also be either lifeless or nothing much above the level of reproducing slime.

Also, we're talking about two different issues: what's remotely conceivably possible, and what's most probable? It may be that you're focusing on the former and me on the latter. Both are valid avenues of thought, I should add.

In reply to an earlier post on Jul 25, 2012 1:53:51 PM PDT
M. Helsdon says:
"First of all, we can't be sure advanced life can develop on anything but an Earth-scale planet with a large captive Moon like we have."

So basically you are setting rules to ensure that only humanoid biped life can be classed as intelligent.

"Remember, I wasn't even talking about intelligent life--I was talking about iron-smelting, tool-using life."

It is entirely conceivable that life could evolve in cold environments where water is actually a rock and technology could be based on very different materials. It just wouldn't be life as we know it.

"That leaves out marine environments anywhere, courtesy of the laws of physics. Has to be terrestrial. Dolphins are cool and have brains as good as ours, but they can't grasp things, they can't smelt--and much of their impressive brainpower is occupied by sonar processing, courtesy of their descent from river otterlike amphibious mammals adapting to turbid water conditions. So though they pass the mirror "hey that's me" test--as do elephants, it turns out--they aren't remotely smart enough to qualify for what I'm talking about."

Hmm, in a very high pressure water environment, it is conceivable that intelligence could employ materials that aren't practical at a mere one atmospheric pressure.

"Could that land be the terrestrial environment of a much bigger high-G planet that made, say, hexapedism superior to quadrapedality? The science book Rare Earth: Why Complex Life Is Uncommon in the Universe--a real buzzkill BTW--convinced me that the "window conditions" for a planet with intelligent life are waaay narrower than I'd imagined. For example, the need for a big Moon, for two reasons: (s) axial stabilization and (b) the collision forming the moon also blowing off our excess water, enabling us to have landforms as well as mineral mixing."

I've read the book, but more recent research indicates that the Moon, whilst responsible for many features that probably make our planet unusual, didn't reduce the water. Earth's water arrived much later, probably during the last heavy bombardment phase, delivered by comets and asteroids.

"Also, we're talking about two different issues: what's remotely conceivably possible, and what's most probable? It may be that you're focusing on the former and me on the latter. Both are valid avenues of thought, I should add."

At present we have only one data point for life in the universe, and that is inadequate for determining how possible other biochemistries and other forms of intelligence are.

In reply to an earlier post on Jul 25, 2012 2:59:00 PM PDT
Ehkzu says:
1. I'm not predefining "life" as "Earth-like life." I'm just saying that we only have one datapoint--one planetary situation--where we're sure life of any sort, much less intelligent life, much less tool-using life--can evolve. Which is pretty much the same as your last point--that we can only be certain that life can evolve on our kind of planet. That isn't speculation, while all the other alternatives are.

Actually we also have a bunch of negative datapoints--the other planets and major satellites of our solar system, where life appears to have developed on none of them. I realize we still have some exploring to do and I hope we do it around our neighborhood, but it looks unlikely so far.

2. Life in cold environments.

I seem to recall reading that such life, if possible, would probably be silicon-based instead of carbon-based, and use (this is a fuzzier memory) methane instead of oxygen for respiration--something like that. The speculation about this that I recall from reading Rare Earth and some other stuff was that such life would proceed at such slow metabolic pace it's vanishingly unlikely that intelligent, tool-using life would evolve out of such an environment. I'd be delighted to be proven wrong. The more life the merrier, as long as it doesn't want to exterminate us like Hawkings fears. But I think we're talking more about the equivalent of bacterial mats and slime molds here, not alien Werner Von Brauns and Sally Rides.

3. High pressure water environments

Well, certainly the fairly recent discovery of alien life forms here on Earth around abyssal hydrothermal vents was pretty mindblowing for biologists and the rest of us who care about such things. However, on the bigger Life Zone water-covered planets astronomers have been talking about, I see their thick hot ice layers as blocking transmission of anything from such planets' rocky cores up into the water. Seems like they'd be vast, deep oceans of distilled water devoid of life under a methane sky. Do you see anything making it through the hot ice layer? Giant volcanoes? If so, maaaaybe there'd be something life could be based on.

I suggest writing a scifi story embodying your speculations about this, as Forward did with his about Neutron stars. Hopefully you're a better writer! His characterizations were cartoonish, even though the ideas were fascinating.

Per my pursuit of the path of greatest plausibility I'm a little dubious, but I'm not certain it's impossible either.

4. Need a big Moon?

The conferring of axial stability is sufficient to mandate having a moon big enough to provide that. Phobos and Deimos need not apply. But you must agree that without that stablity, at some point Earth would wind up with one pole pretty much facing the Sun, and the resulting terrestrial weather would preclude life above the bacterial/perhaps protozoan level.

As for water--which as I said isn't a necessary factor here--isn't it possible that the protoplanet collision blew off our water envelope for the most part and then the raiin of comets 4B or so years ago replaced that water, and if the collision hadn't happened we'd have wound up with too much water then? I can imagine floating somethings or otherses in lieu of land--some extension of the Sargasso Sea's plankton forests underwater--but I woulldn't bank on that. The Aztecs built Mexico City on reed mats, actually, and it led to that city being so susceptible to earthquake damage for a given level of quake.

5. Who knows?

Yes, who knows indeed. As I said, all we can be sure of is life on Earth in all its variety. All else is speculation. Which is why science fiction is most properly called "speculative fiction."

My gripe is that scifi tends to either assume it's all humans all the way down....or the inexplicable alienness of stories like Rendezvous with Rama.
To put it another way, speculative fiction tends to use a lotta black boxes (things we can't explain or think are impossible by what we know) one way or another. I like the idea of science fiction that tries to keep the black box count down to a minium.

But then when I was a kid and the other boys were drawing sports cars and military spaceships, I was drawing sedans and transport aircraft.

I was a strange kid. To which my spouse would say "What do you mean 'was'?"

In reply to an earlier post on Jul 25, 2012 3:53:13 PM PDT
M. Helsdon says:
"I'm just saying that we only have one datapoint--one planetary situation--where we're sure life of any sort, much less intelligent life, much less tool-using life--can evolve. Which is pretty much the same as your last point--that we can only be certain that life can evolve on our kind of planet."

And even if it evolved on our kind of planet, it need not result in a humanoid biped... If you wound back life on Earth several billion years and let it run again, you might not even get multicellular life, let alone mammals or hominids. The history of our species includes at least one (if not more) genetic pinch points where species extinction loomed, so there's nothing inevitable about the rise of intelligent tool-using humanoid bipeds. If we go extinct (and most complex species do, eventually) then the Earth only has a few more hundred million years to 'have another go' (see Ward and Brownlee's other book The Life and Death of Planet Earth: How the New Science of Astrobiology Charts the Ultimate Fate of Our World, which may be overly optimistic).

"My gripe is that scifi tends to either assume it's all humans all the way down....or the inexplicable alienness of stories like Rendezvous with Rama."

But you've already noted examples of really alien fictional life that wasn't entirely inexplicable. Finding humanoid alien life is fairly improbable by your own argument, given just how unusual Earth probably is.

In reply to an earlier post on Jul 25, 2012 4:11:30 PM PDT
Last edited by the author on Jul 25, 2012 4:15:08 PM PDT
The thing is, what makes you think that humanoids, once having achieved technological means, will persist in this form for more than a few millennia? Once we become fluent in gene manipulation and cybernetics, it seems to me that a much wider spectrum of appearances will develop. To be star-faring in any practical way will require that we do something like upload our intelligence into very small packages, such as Charles Stross proposes in "Accelerando".

Accelerando (Singularity)

In reply to an earlier post on Jul 25, 2012 5:30:01 PM PDT
Ehkzu says:
re: given an Earth are we inevitable?

We aren't, and our duration past our current terracide project is hardly guaranteed. However, I said nothing about either in my original post; just that IF the planet developed an advanced tool-using species it would look and act a lot like us.

I'm familiar with the Indonesian volcano pinch point around 80K years ago that took us down to around 1,600 fertile females off the top of my head. And certainly we might not have survived that.

My central point is to emphasize the importance of convergence in evolution and the realization that evolutionary pressure shaped us to a degree most don't realize.

Even our hairlessness, which I thought was an accidental byproduct of the neotony that helped us develop our big brains. But now it seems that it was a requisite for our unique form of mid-day endurance hunting, combined with our copious sweating capability.

2. "tends"

That's the operative term. I was talking about the most popular examples of scifi, not the out of the way stuff that's always there for the diligent digger. Not Gravity World, but Star Bores and Star Dreck and Avatar yada yada.

OTOH I'd stand up for Babylon 5, Firefly/Serenity (despite some technical wowsers), 2001 (I know, no tapirs in Africa)--better shows like those.

In reply to an earlier post on Jul 25, 2012 5:36:19 PM PDT
Ehkzu says:
re: how do I know we'll persist?

I don't. Which is why I didn't claim we would. Or that any intelligent alien race would develop star travel. I think it's impossible, personally.

Species self-modification was explored in The Mote in God's Eye. I could see explorations of that and strong counter-reactions as well. We have enough trouble with people whose skin color or eye shape differs mildly.

But I encourage all here to write stories that reflect their personal prognoses and concepts. Let a thousand flowers bloom.

One other point: I know that the slow warming of the Sun only gives a living Earth a few hundred million years more. However, it is technically feaible--possibly even today--to build a mylar parasol at L1 that would let us stick around longer. Humanity might not have the psychological wherewithal to do such a project even if our existence depended on it, but it is a possibility. And another storytelling possibility. Imagine living under a screen like that with certain seas-boiling-off-everybody-dies seething away right on the other side of it? Might focus people's attention on the important things...

In reply to an earlier post on Jul 26, 2012 1:48:30 AM PDT
M. Helsdon says:
"My central point is to emphasize the importance of convergence in evolution and the realization that evolutionary pressure shaped us to a degree most don't realize."

Even so, alien intelligence won't converge towards the humanoid because it will derive from a different biological basis. In the case of a hypothetic intelligence dinosaur, it would in all probability retain a tail and a forward leaning stance.

"Even our hairlessness, which I thought was an accidental byproduct of the neotony that helped us develop our big brains. But now it seems that it was a requisite for our unique form of mid-day endurance hunting, combined with our copious sweating capability."

In which it derives from the hot dry grasslands our distant ancestors lived in, but, if instead of the plains of Africa they had evolved in a colder climate, say, Europe or northern Asia, they'd still be hairy. For that matter, people of European descent tend to have more body hair than people of African descent.

"That's the operative term. I was talking about the most popular examples of scifi, not the out of the way stuff that's always there for the diligent digger. Not Gravity World, but Star Bores and Star Dreck and Avatar yada yada."

In Avatar the Na'vi were originally designed to be less human (I don't know if they were planned to be hexapods like other Pandoran life) but a direct decision was made to make them more human to appeal to the audience.

"However, it is technically feaible--possibly even today--to build a mylar parasol at L1 that would let us stick around longer. Humanity might not have the psychological wherewithal to do such a project even if our existence depended on it, but it is a possibility."

Such a parasol approach is decidely low tech. Niven's A World Out of Time suggests another approach...

In reply to an earlier post on Jul 26, 2012 8:54:57 AM PDT
Firstly, let me say that it is remarkable how many of the scifi same books we have read! (Have you been burglarizing my bookshelf in the night? I can't seem to find my copy of "Dragon's Egg.")

I assume you have read Hoyle's "A for Andromeda". In that story, the information transmission was one way, and--as usual--problematic for the host planet. But I can imagine a scenario in which two distant species might cooperatively agree to an even exchange of data, so that each now had the benefit of having an outpost/foothold on another sun. Although the risks are great, the upside potential for the continuation of each species might be seen to outweigh the downside. Would this count as "interstellar travel"? And do you think it is impossible?

Personally, I think an awful lot of evolution can occur in a few hundred million years--especially now that self-direction is becoming feasible. Yes, there will be counter-reactions, as there is to any significantly jarring technological development. But somehow, they seem to happen, regardless.

I also think that biology, by comparison with cybernetics, is hopelessly slow in its evolutionary trajectory. Electronics and robotics have progressed at a positively astounding rate in the past 50-100 years. Do you see a reason why this would cease to be the deciding factor? Do you think that artificial intelligence that overtakes human intelligence is inherently impossible? What will be the roadblock?

Posted on Jul 26, 2012 9:44:42 AM PDT
Yeah, that's why Vulcans and Klingons don't look so different from us.

In reply to an earlier post on Jul 26, 2012 2:27:43 PM PDT
Ehkzu says:
I just accidentally erased a long, detailed response to Helsdon's points. @%#$%#$%!

Here's the short version:

My central point is that whatever path you take winds up in erect bipedal terrestrial humanoids, whatever ontogeny their phylogeny recapitulates. Our ancestors had tails of course and lost them because they prevent efficient inverse brachiation. Same would happen to a tailed dinosaurian. Hairlessness is also required for nuanced faciallyh mediated communication, and note that even Eskimos are pretty hairless, along with all other Orientals. Maybe we Euro-derived humans are just more atavistic than the other races (!).

What you said about making the Nav'i less anthropomorphic was more realistic for less scientific reasons--kind of ironic. J. Michael Stracynski did the same thing with the Membari on Babylon 5--and a good thing. Shame to hide Mira Furlan under all those prosthetics as was done in the pilot.

Moving Earth farther out has been discussed. Might be possible by maneuvering (if we can figure out how to do it) an asteroid to fly by Earth very close to it, over and over, for many thousands of years, nudging Earth slightly farther out in its orbit each time. A lot less blue sky than a parasol. If we survive that long we also need to deal with the Moon, which is slowly escaping its orbit, and woe betide us (nudge nudge wink wink) when it goes.

In reply to an earlier post on Jul 26, 2012 2:30:06 PM PDT
Ehkzu says:
re: Vulcans and Klingons

Ironic that special effects budget limitations and audience need for humanoid aliens so they can relate to them kinda would result in more scientifically plausible aliens than more fantastical ones would be.

But then life is full of these little ironies, isn't it?

In reply to an earlier post on Jul 26, 2012 2:44:57 PM PDT
Ehkzu says:
Randall, my degree's in sociology, plus long study of sociobiology (enough to get a teaching credential in biology by exam), plus 20 years as a writer/editor of computer science stuff for magazines aimed at corporate software developers. So really I'm just a layman in all of this with a patina of knowledge stretched paper-thin over an abyss of ignorance.

Will we be able to transfer our consciousness to a machine? I'm dubious but not about to write it off either.

Wouldn't it have been great if the movie Contact had lived up to the promise of its first third instead of wandering off into Hollywood mellerdramaland?

Self-evolution a la The Mote in God's Eye certainly seems like something or other will become feasible, and as you noted, what becomes feasible gnerally seems to happen. Though we've done pretty well at holding off on nuking each other for 67 years. Yay team! Messing with our evolution will start with trying to fix our autoimmune systems going haywire and our cells misprogramming themselves producing cancers. That is, changes that won't affect how we look.

Now we have evolved dogs (and goldfish, poor things) to suit us. Maybe that's the model, from mastiffy war dogs to house pet Yorkies etc. But we're so intensely, innately tribal, so prone to identity politics even when the opposed sides are virtually identical (Northern Ireland for example)...hard to avoid seeing anyone who looks really different getting the short end of a genocidal stick, isn't it?

Even when they don't look any different. That was my experience growing up in blue-collar schools as a kid, certainly. Rejection and harassment from start to finish.

In reply to an earlier post on Jul 26, 2012 3:26:24 PM PDT
<<Will we be able to transfer our consciousness to a machine?>>

Why would this be necessary? Wouldn't it be sufficient just to have human-level intelligence? (I did not transfer my consciousness to my son, although I like to think I had some part in the development of my son's conscious thoughts.)

Let me add that the raw data size of a human genome is quite small... It fits on one CD-ROM. Maybe another CD-ROM or two's worth of genetic sequencing machine blueprints & basic chemistry data, and it seems to me that even a moderately technological culture could do what was done in "A for Andromeda". Add a few more for the cultural information (encyclopedias, etc.) to educate the transmitted being, including data on basic support ecology, and Voila'! Transplant successful!

All of this would be easier to implement under the assumption of your thesis, namely that the basic parameters of the planet would have to be relatively similar. Presumably, there'd be organic chemistry there, already--including common amino acids, oxygen/nitrogen atmosphere, water-based oceans, etc.

In reply to an earlier post on Jul 26, 2012 3:37:23 PM PDT
M. Helsdon says:
"My central point is that whatever path you take winds up in erect bipedal terrestrial humanoids, whatever ontogeny their phylogeny recapitulates."

Which you have yet to prove, because...

"Our ancestors had tails of course and lost them because they prevent efficient inverse brachiation. Same would happen to a tailed dinosaurian."

...biped dinosaurs retained their tails and walked on the ground for tens of millions of years.

Dale Russell's humanoid dinosauroid, which conforms to your thinking, has been widely criticised by other paleontologists: 'At least one reviewer of Russell & Séguin's paper wrote that `I do not see much value in the extremely speculative `dinosauroid' discussion' (Russell 1987, p. 127). In Predatory Dinosaurs of the World, Greg Paul (1988) found the dinosauroid to be `suspiciously human', and he argued that - were theropods to evolve big brains and `intelligence' - we should instead expect them to retain horizontal bodies and long tails. Theropod expert Tom Holtz has stated much the same, and so far as I can tell from discussion, most dinosaur workers feel this way too. There really isn't any reason to think that big-brained dinosaurs would have evolved in the first place (recall that even `big-brained' Troodon was, at best, on par with ostriches and opossums), and even if they had, there is also no reason to think that they would have ended up looking like scaly people (or feathery people, given that we now know that troodontids were feathered). The reason that we humans have the body shape that we do is not - I think - because it's the `best' body shape for a smart, big-brained biped to have, it is instead the result of our specific lineage's evolutionary history. Given that, so far as we know, the humanoid body shape has evolved just once, we simply have no way of knowing whether it's a particularly `good' morphology or not. Furthermore, the humanoid body shape is not a prerequisite for the evolution of big brains given that brains proportionally as big as, or bigger than, those of hominids are found in some birds and fish (that's right: humans do NOT have the proportionally biggest brains).'

http://darrennaish.blogspot.co.uk/2006/11/dinosauroids-revisited.html

"What you said about making the Nav'i less anthropomorphic was more realistic for less scientific reasons--kind of ironic. J. Michael Stracynski did the same thing with the Membari on Babylon 5--and a good thing."

It's also because humanoid aliens are cheap to do, even if they aren't realistic.

"Shame to hide Mira Furlan under all those prosthetics as was done in the pilot."

Babylon 5 offered her a lifeline given that she and her husband had to flee the situation in Yugoslavia (being married across the Slovenian-Croatian/Serb divide). In her own country she was a very high status actress, wining the Yugoslav Golden Arena twice.

In reply to an earlier post on Jul 26, 2012 5:34:01 PM PDT
Ehkzu says:
Helsdon, you need to distinguish between "walking" and "efficient inverse brachiation." Lots of animals walk. Our flavor has the virtue of being (a) amazingly efficient in terms of calories per hour at, say, 2mph and (b) despite the unique specializations providing this efficiency at flat travel, it doesn't lose us our climbing ability. Velociraptors couldn't climb trees. We can.

And as I said in my last entry, the standard dinosaurian locomotory design does not lend itself to advanced tool-using, as ours does.

The blog you quote is correct, I believe, in terms of the anthropomorphization of Velociraptors for Jurassic Park. Ostrich-level IQ (and they're real birdbrains) seems more accurate.

However, the bloggers quasidismissal of our design being particularly advantageous sounds ideological to me.

Remember, in the history of biology there was this Bergsonian claptrap about Life having some kind of pan-consciousness coupled with all Life striving to perfect itself by producing...us. This history contributed to the Splitters' Steven Jay Gould-style abhorrence of admitting anything but unique accidents of history producing everything.

The problem I have proving my point is that our intelligence makes us unique, while I can easily prove convergence in the example of large pelagic predators--sharks, ichthysaurs, cetaceans, mahi-mahi, swordfish--it's all there. Whereas to prove my thesis we'd have to visit a bunch of life-bearing planets with intelligent life and see what the most common designs are.

Splitters have to acknowledge the many, many examples of convergence in evolution because they're a matter of record. But then they claim that convergence isn't a factor in our design.

And the big brain part is a bit of a canard. Mormyrid fish have a bigger brain/body ration than we do, but the absolute size it teeny and they aren't strongly convoluted, plus they lack all that cerebral cortex/forelobes that account for us having so much in RAM. Elephants have huge brains but huger bodies, saddling those brains with a lot of "administrative overhead." Actually elephants have better memories than we do in some ways, but inferior processing power. Dolphin brains are as advanced as ours and with similar brain/body ratios and absolute size, but are saddled with a different kind of administrative overhead: sonar processing.

So no other animal approaches human mentation.

Splitters assume everything is chance/accident unless you can prove otherwise.
Lumpers assume everything happened for evolutionary reasons unless you can prove otherwise.

I'd like to see an alternate evolutionary model for an advanced tool-user that isn't like us. I don't think you can get to that from a horizontal body balanced by a big tail walker like the--is it therapods?--without them having to get upright and develop brachiating shoulders/arms/hands.

Also remember that our upright stance preceded our big brains by at least 5 million years. That stance was quite advantageous for our ancestors, even without the brains. For one thing, it let us see farther on the veldt than any quadraped with comparable body mass. And our particular mass was a good compromise between the safety of size (the monkeyheaded us were a lot shorter, though) and the need to find enough calories to keep that mass sustained. And since we could climb trees and whatnot being able to see danger at a distance also meant we could often escape the danger by climbing as long as we had a head start. Human eyesight indicates it being optimized for open forest, after all.

In reply to an earlier post on Jul 26, 2012 8:48:39 PM PDT
no
you will never transfer nor create consciousness in a machine

In reply to an earlier post on Jul 26, 2012 10:29:38 PM PDT
Ehkzu says:
That's my default assumption--especially since we don't know what consciousness is yet--not in us, not in other animals. Look into a pet dog's eyes and you know there's something or other in there.
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Discussion in:  Science forum
Participants:  17
Total posts:  137
Initial post:  Jul 25, 2012
Latest post:  Aug 14, 2012

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