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Eight-Armed Animal Preceded Dinosaurs
Garimelda writes "Scientists have discovered what they believe is an eight-armed creature which colonized a large section of the world's oceans over 300 million years before the first dinosaurs emerged."
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Eight-armed, in the sense that a starfish is five-armed. Not quite as sci-fi weird as the headline might sound.
So I would take it that these creatures would have invented personal deoderant before the wheel?
Well, there's spam egg sausage and spam, that's not got much spam in it.
The passing of our 8 legged, sea dwelling, Gondwanalandish ancestral overlords
I am Slashdot. Are you Slashdot as well?
Cthulu--the ancient one!
I might know what I'm talkin' about, but then again, this is Slashdot...
I recall people studying the evolution of locomotion by allowing any kind of movement- walking, tumbling, slithering, wheels, etc. Computer programs "evolve" trying random mutations and look at resulting locomotive efficiency. Some clever, unexpected solutions result which you dont see in nature. I forget the reference, but may be associated with the Sante Fe Artificial Life Institute, etc.
I'll believe ID when they find a fossilized watch.
Any life is made up of a single moment, the moment in which a man finds out, once and for all, who he is.
Given the time scales involved, that's kind of like saying "Alexander preceded Napoleon" -- I mean, it's true, but it leaves out a whole lot that happened in between.
Oh, never mind. The past is telescoped. There's old stuff (things that happened before my parents were born) older stuff (George Washington and other guys in funny clothes) very old stuff (King Arthur and Robin Hood) extremely old stuff (cavemen and dinosaurs) and, apparently, incredibly old stuff (before cavemen and dinosaurs -- who knew?) No point in asking people to maintain a sense of persepective.
The correlation between ignorance of statistics and using "correlation is not causation" as an argument is close to 1.
I'll believe ID when they find a fossilized watch.
It's even still hard to believe... http://www.fossil.com/webapp/wcs/stores/servlet/ContentView?langId=-1&storeId=12052&catalogId=10052&categoryId=30005&parent_category_rn=30000&N=0&contentPageHtml=watch_non_catalog
Oh god. I've been trying to forget those for over ten years now, and now you've brought all the horror back. In case anyone doesn't know, Clarke's Rendezvous with Rama is a science fiction classic that only gets better with age. The sequels made in collaboration with Gentry Lee, however, have no touch of Clarke's genius. It's suggested that Gentry Lee penned them all by himself, and his interests were peculiar indeed. The third volume of the series has some of the most ridiculous sex ever found in science fiction, a genre already infamous for bad erotic scenes. Then, in the fourth volume, Lee reveals that the mysterious aliens whose starship humans had boarded were, in fact, angels serving the Christian God. Though why an omnipotent deity works through robots and subjects races to agonizingly slow slower-than-light travel is never explained.
To me, the most interesting aspect of these early, pre-Cambrian-Explosion fossils was that bilateral symmetry (which is the norm for practically all animal life today) was nothing special. You had lots of organisms that were radially symmetric or just plain asymmetric. Whatever mass extinction event wiped out the majority of the Ediacaran biota gave a foothold to the bilaterally symmetric ancestors of modern animal life, which then dominated the Cambrian Explosion. It is just a fluke of evolution that we are not radially symmetric or asymmetric. Shades of Niven & Pournelle's Moties!
what does God need with a starship?
the preceding post was not spell checked... suck it.
I'm at a loss to think of any two-limbed complex organisms.
Pirates!
We don't have 5-fold symmetry. We're bilaterally symmetric; we have a top, bottom, left, and right. A starfish has a top and bottom, but no left or right. For what it's worth, not even a five-armed starfish has exactly 5-fold symmetry. They are considered radially symmetric, but are thought to have evolved from bilaterally symmetric organisms and have some structures that show this.
I've had it with these mother fucking eels on this mother fucking hovercraft!
Escher was the first MC and Giger invented the HR department.
1. Well, you have to also realize that different environments might favour different configurations. For example an octopus doesn't use its noodly appendages in the same way as you use your legs, and not even like a fish uses its fins.
Each is optimized for its particular use. It's safe to assume that for a fish that particular tail and fin configuration is good, because it evolved several times from something different to that exact configuration. E.g., dolphins evolved to the same scheme, but so did Ichthyosaurs, Plesiosaurs and Mosasaurs, plus a few of their relatives and ancestors. There are two different configurations of four legs which evolved into such a fish-like configuration that Ichthyosaur skeletons were first believed to be fish. So it's safe to assume that for that style of swimming, a fish-like configuration is optimal, and indeed better than four legs or even than two legs.
Two legs vs four legs also seems to be not that clear cut. The two-legged configuration evolved independently more than once, so it must have _some_ advantages. E.g., all dinosaurs are descendants of a two-legged ancestor. Some, however, returned to four-legged afterwards. Some evolved into birds instead. So again it's probably safe to say that each is good... for a given environment.
Insects are a funny case, because again they're used differently than you use your legs. Insect legs are autonomous. Each leg has its own autonomous "controller", or rather its own mini-brain. The insect's head just gives an order like "forward" and all legs independently start doing the movements for moving forward. That kind of a wiring would be totally unfit for bipedal use. Heck, even four would be more miss than hit. So an insect must necessarily have a larger number of legs. For the way an insect is built, really, six legs are good, two legs are bad.
2. But even that is over-thinking it, because the little guys in TFA didn't actually have arms or legs like you. They were really jellyfish with 8 long tubular appendages. There are no muscles there or bones or exoskeleton or anything usable for locomotion at all. The whole thing was really two thin layers of cells, little more than a microbial film, with an amorphous jelly in between. The "arms" were probably more to give it more surface and reach from which it can absorb nutrients, than for anything else.
We're talking _very_ primitive multi-cellular life forms.
A polar bear is a cartesian bear after a coordinate transform.