Alien, I mean really Alien.

[Captain Kwok]

Originally posted by Randallw:
Anyway in the example I mentioned there were 20 "forms" of animal found. Thats the 5 current ones, and 15 "types" that are extinct.

It's actually a bit different than that...

In reference to animals, there are actually 34 basic forms "phyla" currently classified. Although they've developed at different times in history, I don't believe any have gone extinct. Mostly they've just gotten more complex (but not always sort of)!

From an evolutionary and multicellular viewpoint, things have progressed like this:

Sponges "Porifera" - No tissues; like a colony of single-celled organisms

Jellyfish, Corals "Cnidaria" - True Tissues (two); radial symmetry; partial digestive cavity; nerve net

Flatforms "Platyhelminthes" - no body cavity; bilateral symmetry; full digestive cavity; 3 tissues; head ganglia (nerve center)

Rotifers "Rotifera" / Roundworms "Nematoda" - pseudocoelom (sort of have a body cavity); 3 tissues; have "butts" and mouths ; head ganglia with primitive nerve cord

Segmented Worms "Annelida" - body cavities; 3 tissues; exoskeleton; circulatory and digestive system; head ganglia, simple nerve cord

Insects, Crustaceans "Artropoda" - body cavities; 3 tissues; exoskeleton; circulatory, digestive, and respiratory systems; head ganglia, increased nerve network

Octopus, Snails "Mollusca" - body cavities; 3 tissues; exoskeleton; circulatory, digestive, and respiratory (gills, lungs) systems; brain; nerve network

Sea Stars, Urchins "Echinodermata" - bilateral symmetry (but radial adults!), 3 tissues, body cavity, endoskeleton, no circulatory or excretion system, no brain, nerve network in skin

Vertebrates (Us!) "Chrodata" - 3 tissues; bilateral symmetry; developed digestive, circulatory, respiratory systems; developed brain; nerve cord; endoskelton

I'd imagine alien life given similar conditions as Earth (O2 + water) would progress in a similar fashion. I don't think its nearly as random as you'd think. If you want to have complex organs like eyes and ears, you're going to require some sort of sophisticated nerve system and brain to process and interpret that info. Big brains require lots of energy, so you'll need to be mobile and have sophisticated respiratory, circulatory, and digestive/excretion systems for that to be possible, and so on.

Of course, other factors like the planet's gravity or surface conditions may dictate physical appearance or types of sensory organs (i.e. sonar, electromagnetic, etc), but the internal mechanisms would be probably be quite similar. After all, evolution is just a process of selection - and given the same sort of conditions you'd expect given enough time, to see the same end results.

Originally posted by Randallw:
Basically 1 billion years ago there were 20 possible templates for the creatures that would occupy the earth but 15 got covered with a landslide and only the other 5 survived (I am simplifying this alot, and my numbers might be wrong, but I am trying to point out something). So what if instead of the 5 that survived, 5 others survived. The earth might be populated by animals with no backbone and 3 legs and a head with an extendable mouth.

I think your end conclusion is a little far-fetched, but your general idea holds true on a smaller scale, i.e., Dinosaurs vs. Mammals sort of scale. If the Dinosaurs had been able to hang around longer, then perhaps we'd be more of a Reptillian-humanoid...however, we'd still have the same body systems and macroorgans that we do now. It's just a good setup for evolutionary success.

Now, talking about other types of planets and possible life or intelligent Alien behaviour - that's just another serious can of worms.

[ March 25, 2004, 19:43: Message edited by: Captain Kwok ]

[dogscoff]

I don't really follow your example of alien dolphin-like animals, either. Of course scientists would study the heck out of any alien life form. Scientists study dolphins, too.

My point is that we assume dolphins aren't sentient because we have thousands of years of history defining them as 'dumb animals'. SUppose dolphins didn't exist on Earth, but on planet Blarg. Now suppose we sent a spaceship to Blarg and discovered the dolphins, frolicking and singing to each other. WOuold we say "they're just a bunch of clever but sub-sentient animls" or would we start with the assumption that they might be sentient and work our way up? And if we did the latter, what would we find?

I guess what I'm saying is, we take the various life forms we already have for granted. If we were to look at them with fresh eyes we might be surprised.

But I can't remember what this has to do with xenodiversity. someone remember to ask me when I sober up.

[Slick]

Originally posted by dogscoff:

quote:

---

I don't really follow your example of alien dolphin-like animals, either. Of course scientists would study the heck out of any alien life form. Scientists study dolphins, too.

My point is that we assume dolphins aren't sentient because we have thousands of years of history defining them as 'dumb animals'. SUppose dolphins didn't exist on Earth, but on planet Blarg. Now suppose we sent a spaceship to Blarg and discovered the dolphins, frolicking and singing to each other. WOuold we say "they're just a bunch of clever but sub-sentient animls" or would we start with the assumption that they might be sentient and work our way up? And if we did the latter, what would we find?

I guess what I'm saying is, we take the various life forms we already have for granted. If we were to look at them with fresh eyes we might be surprised.

But I can't remember what this has to do with xenodiversity. someone remember to ask me when I sober up.

---

Sounds like what happened in "So Long and Thanks for all the Fish"

Slick.

[ March 25, 2004, 20:39: Message edited by: Slick ]

[narf poit chez BOOM]

Originally posted by dogscoff:

quote:

---

Dogscoff, what your saying is that they may develop a fear reaction, but they won't be feeling fear?

Well, if it serves the same purpose as fear, and it provokes the same response as fear... why don't we just call it fear? There will undoubtedly be biological differences but the end result is the same. After all, how do i know that when *you* feel fear you feel the same thing as me? How do I know you don't see red as what I would call call blue?

It's like the Turing test for AI: You can't know for sure whether a machine is actually intelligent or just doing a really good impression of one that is, but when it gets to that stage there's very little point trying to tell the difference anyway.

---

What you seem to be saying is that 'you can't know how other beings think, so they might be thinking differently'. I'm saying, if stimuli and responce can be made to match up, then why should they be different?

I'm also saying that any different stimuli and responce can be simulated with the human brain.

[PvK]

Originally posted by dogscoff:

quote:

---

I don't really follow your example of alien dolphin-like animals, either. Of course scientists would study the heck out of any alien life form. Scientists study dolphins, too.

My point is that we assume dolphins aren't sentient because we have thousands of years of history defining them as 'dumb animals'. SUppose dolphins didn't exist on Earth, but on planet Blarg. Now suppose we sent a spaceship to Blarg and discovered the dolphins, frolicking and singing to each other. WOuold we say "they're just a bunch of clever but sub-sentient animls" or would we start with the assumption that they might be sentient and work our way up? And if we did the latter, what would we find?

I guess what I'm saying is, we take the various life forms we already have for granted. If we were to look at them with fresh eyes we might be surprised.

But I can't remember what this has to do with xenodiversity. someone remember to ask me when I sober up.

---

Ok. I'll also ask what the disagreement with what I was trying to say was, because I entirely agree with you on this. In fact, the humans that assert that animals (from dolphins to rats) are "not intelligent" or "sub-sentient" are either just plain wrong, or are framing their questions in ways that I think are rather off.

PvK

[dogscoff]

hmm, I seemdd to have generated some replies. If only I could rememebr what the hell I was talking about. But, to reply to everyone at once: Yes/no/thanks/of course/sorry/curses!/oops (delete as appropriate)

[Atrocities]

There are no aliens living on other worlds. It is mathamatically improbable that sentient space faring life could have evolved on another world given the absolute uniqueness that spawned life here. The chances for another life giving planet are so astronomically rare that if you could explore space in its entirety in one day it would take you a trillion years to find one planet like Earth. We are it and until one lands on this planet and proves me wrong, I am going to stick by this narrow minded concept.

[Captain Kwok]

Atrocities:

I'll give you the chance that Aliens visiting us here is next to nothing, but I sincerely doubt your assertion that there is no alien life elsewhere in our galaxy. Once we have better tools in place, we'll start identifying planets much more like our own than the ones they've found so far.

[Atrocities]

CK I have to tell you that our being here is an accident of epic proportions. The simple fact that life evolved on Earth is such a rare event that chances of it occuring twice or more in the universe is so great that if you took the number 1 and put 0 behind it to the point that it could circle the universe a centrillion times to the billionth power you might be within 1% of the chance.

This planet is so rare that it equals 1 10th of a grain of sand compared to the entire galaxy. And we are wasting it away.

No CK, life does not exsist "out there" it only exsists here.

[Captain Kwok]

...and what do you base this on? Your own pessimistic view?

Nah, I'm hoping that one of the Mars rovers will accidently stumble upon some microfossils to spite you.

All in good humour of course.