Aphelion

"It's life, Jim, but not as we know it . . . "

http://science.nasa.gov/science-news/sc ... _monolake/


Now, we really do have to start looking at biology in new ways. Any biochemists out there? What else can be substituted into DNA and still have it work?

Tao, could you describe those ten? I personally favor the centauroid as one that would work well, except maybe not for climbing trees. And, no, I'm not talking about a man's torso on top of a horse's, but something a little more well-integrated and sensible. Four walking legs and a pair of arms just seems like a really flexible and adaptable body plan to me. And, given some of the other weird shit that evolution has tried -- like four-winged birds -- I'm damned if I can understand why we haven't seen a centauroid variant of some sort.

Carbon is just the phenomenal power hitter of the periodic table. Basically, it spins both ways, acting both on the metal side and the gas side of the periodic table, and even with itself in chains. It's that ferocious flexibility that makes life possible.

Yep, carbon is like a slutty, sooty, pansexual nymphomaniac; with such a convenient arrangement of covalent electrons, it'll couple with just about anything, in nearly endless ways. Coincidentally, there's lots of it, just about everywhere, so it almost can't help being an important ingredient in self-replicating molecules.

And I can't get my mind out of the gutter . . . c'mere, carbon . . .

My vote on why we haven't seen a full centaur is that the big torso is a colossal waste of space unless it contains *different* organs than the horse body.

You don't want a horse, of course, of course . . . the classical Greek model is downright laughable; two torsos with duplicated major organs . . . here's how I envisioned it:

a Chinese dragon on stilts -- with arms -- and two opposable thumbs on each hand. Face more like a velociraptor, with binocular vision. And feathers, everywhere except the face and the arms and lower legs, which showed leathery, dull-yellow skin. Big diamond-shaped paddle of feathers at the end of the tail.

The snakelike body is sufficient for one set of internals.

There's kinda a problem on where to put the arms without that human torso on top.

I don't think it's that big of a problem . . . you just need the shoulder girdle to be sufficiently distinct from the front leg assembly -- and we now need a new term for that -- forehips? The ribs are all between the two sets of legs, and there's enough spine between the arms and front legs to allow flexibility, so it can maybe reach around and put a load on its back.

Consider also that brains don't necessarily have to be in the head -- that just works well to keep them cool, because they do generate a lot of heat. Solve that problem, and you can make the head smaller and lighter to improve balance and streamlining, and make the thing harder to kill in the bargain.

Snake Class
There's scope here if they're phenomenal tool users.

How are they going to use tools if they don't have arms? Am I missing something? Perhaps cooperative effort among groups, manipulating things with their mouths and tails?

I think an important feature -- almost a flat-out necessity -- is the ability to carry loads while walking or running. If you think about it, this may be a prerequisite to making or using tools. What form that takes is up for grabs.

BD, in a way, I can agree with you, but that leaves the problem of developing tool use and technology. These may not be requisites for intelligence, sentience, or civilization, but they do tend to associate closely, and . . . how much technology are you going to develop under water? Metallurgy is pretty well out of the question, but what else is available? My guess is that a marine/aquatic society is going to be largely limited to the manipulation of biology, since so much of the rest of science is out of reach, requiring the controllable use of extreme temperature. Also, they have no use for buildings in the way that we do, and their only need for vehicles would be along the lines of an environmental container to protect them from extremes of depth that they aren't adapted to.

That still leaves some interesting possibilities, though, for certain.

Tao, looking again at your list of groupings, I think it might be helpful to start over by separating those into two meta-classes, defined by where they fall under the square-cube limits. Beings with exoskeletons can be much larger in lighter gravity fields, or in a buoyant state (submerged in fluid).

Then, you can start with a different group of sub-classes. Some of yours overlap as being bipedal (which should have included the ostrich, btw).

Your basic choices for flight are on the bird-insect scale.

Yes, anything using a gas balloon is too delicate for survival, IMO.The bird-insect scale spans both sides of the square-cube limit, too.

I mentioned hybrids earlier because I want to stay out of "toggling" exoskeletons vs feathers - they're still the same class. Same with bird vs insect postures and wing design - at the end of the equation it's mass vs wing size with enough room for a senient brain, and I simply think anything below a small bird isn't enough cells.

Don't discount the little things; look at ants, termites, and bees. Are they intelligent? Maybe not in a way we recognize, but they do some pretty amazing stuff, including very rapid and effective communication, organization, and task specialization.

Consider this, my own personal real-life experience with some ants: I was bored once, and decided to make the local ants miserable. They were traveling at a very precise interval, single file along their trail, and passed between two posts on the porch. I took the croquet mallet and proceeded to whack each one as it walked between the posts. I'd smashed a dozen or two, and then they stopped crossing the space. I wondered what was up; looked at what they were doing . . . they waited behind the post where I couldn't get them, and when there were maybe a dozen or so, they dashed across all at once, spread out and running in irregular paths, so I was only able to hit a few, and the rest made it unharmed. I realized the little fuckers had outsmarted me, and I never bothered them again. Isn't that intelligence?

As to birds, check this out:

http://www.amazon.com/Bird-Brains-Intel ... dogpile-20

Turns out that for a long time, we were looking at their brains and discounting their capabilities, because we didn't recognize anything like a forebrain. It's there -- we just didn't recognize it -- called the hyperstriatum. Yeah, there's the weight/lift problem, so they don't weigh themselves down unnecessarily, but they have enough to do rudimentary problem-solving, including a little tool use.

Nice, bd, but how do you suppose some marine creature is going to utilize that heat? (I've been aware of thermal vents for a while, btw.) The best I think they could hope to manage would be to find a long stick and hold something in the vent's outflow to cook it -- if they thought that was worth the trouble and risk. The possible payoff is limited, since the temperatures don't get high enough to do very much that's technologically useful, like making steel or even glass. The risk is high, because (as Robert Ballard found out) the currents created by these vents pull nearby objects (including submarines) into them -- very dangerous. Ballard was aboard the Alvin when it almost met a tragic end in exactly this way.

If you see the guy next to you get sucked in and fast-fried, how willing are you gonna be to try it next? And they don't even have beer to make them extra brave.

I'll grant a possibility, but -- we've already seen that the probability of technological civilization on land is 1.0, and -- even given millions of years for a head start, the demonstrated probability for undersea technological civilization is 0.0.

Right; it might be there, but we just haven't found it yet.

Oh, and a couple other things . . .

Your undersea folk won't be inventing the wheel very early, because they won't need it for transportation.

In fact, if you look at all six of the basic simple machines: wheel and axle, lever, wedge, pulley, screw, and inclined plane -- nary a one of 'em is gonna work anywhere near the same under water as they will up in the free air, where we have gravity acting without the counter-influence of buoyancy. Some of them will be largely useless for anything at all.

Gravity is responsible for technology! Who'd a thunk it?

So, bottomdweller -- what kind of technology is going to arise from the depths?