Invalid hypothetical anatomy


Archy is speculating about Gould’s idea that if you rewound the tape of life and replayed it, you might get some very different results…and he suggests that in a different world, molluscs could have replaced vertebrates as the dominant large metazoan. This is perfectly reasonable, but he chose to illustrate the concept, and my SIWOTI syndrome kicked in.

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Noooo! He’s got an arrow for a “large brain” pointing to an enlarged fleshy flap above the eyes. That’s not where the cephalopod brain is located! They have a ventral nerve cord — the central brain would be deep, between the eyes and behind the beak, wrapped around the esophagus.

In this alternate universe, the intelligent cephalopods would be speculating about how those primitive, stupid vertebrates could have evolved into something as clever as they are, and they’d draw something frog-like and point to a puffy throat-sac and say, “look at its big brain!”

But OK, the ray gun is cool.

Comments

  1. KKBundy says

    Bah, everyone knows that if given a second chance, nematodes would reign supreme. It’s a Biblical fact that worm dominance was part of God’s plan until Evetode ate that damn fruit.

    The world has been piss-poor ever since.

    Blessed Atheist Bible Study @ http://blessedatheist.com

  2. blf says

    In a rewound tape, the brain could be anywhere…

    Most likely, on the cutting-room floor.

  3. mmelliott01 says

    In before “I welcome our <hegemonic species> overlords”.

    I’ve always wanted to do that. You can send me to the dungeon now.

  4. Ed S. says

    the central brain would be deep, between the eyes and behind the beak, wrapped around the esophagus.

    Hmm,even more susceptible to ‘brain freeze’ than us humans.

  5. 'Tis Himself, OM says

    But OK, the ray gun is cool.

    What about the tentacles? Aren’t they cool too?

  6. Naked Bunny with a Whip says

    *pew pew pew*

    Needless to say, humans have still evolved and reached caveman levels, enslaved by the molluscs. So says Hollywood Science.

  7. ted.dahlberg says

    Hah, and just yesterday I got to a bit in the book I’m reading at the moment (Chasm City by Alastair Reynolds) where it (briefly) discusses the ecology of a planet where vertebrates never evolved and invertebrates filled a lot of the niches occupied by vertebrates on earth.
    Before anyone rushes off to get the book because of that; it’s a very minor plot point. Still a good read though.

  8. jackal.eyes says

    They have a ventral nerve cord — the central brain would be deep, between the eyes and behind the beak, wrapped around the esophagus.

    Does swallowing put pressure on their brains?

  9. Sili, The Unknown Virgin says

    I still say that it’s impossible to develop electronics in saline. Only tree octopodes are capable making rayguns.

  10. Colin says

    Sili

    I still say that it’s impossible to develop electronics in saline.

    Well, it might not be impossible, but it would be shocking if it happened. :)

  11. PZ Myers says

    So, Sili, how does your brain work? Mine is a salty soup with lots of fatty tubes in it.

  12. cypherpunks says

    You guys might want to check out the science fiction book Mother of Demons, about a society of terrestrial invertebrates (generally similar to molluscs or cephalopods, but of course it’s an independent evolutionary lineage, so they aren’t) meeting a group of “demons” (human refugees from a crashed spaceflight).

    Full text available online if anyone wants to read it.

    Unfortunately, they’re not quite at the ray-gun stage.

  13. davem says

    PZ:

    So, Sili, how does your brain work? Mine is a salty soup with lots of fatty tubes in it.

    Yikes! I just ate that for lunch. Am now feeling quite ill…

  14. Thanny says

    I never did like the “rewind the tape” concept, because it’s really not saying anything at all interesting.

    If you literally back time up to 4 billion years in the past, then hit play again, every physical event that happened the first time around would happen the second time around (as in Nietzsche’s nightmare), which means exactly the same history of life would play out again.

    If you just reproduced a new young Earth at some other random place in space and time (assuming the same kind of sun), then of course that history of life would diverge from ours. But if you claim that’s somehow meaningful or important, you’re just acting like Yogi Berra, saying that if things were different, they wouldn’t be the same.

    If you think QM actually makes the first condition impossible (i.e. you think random effects at the quantum level would make macro-level events different over those 4 billion years), you’re just repeating the second condition – things would be different, because they were different.

    Or are we really trying to convince the loons that evolution really is contingent, and that featherless bipeds with big brains won’t always emerge? Does anyone even really think they would? Claims that intelligence would inevitably evolve aren’t the same thing (and are defensible, provided you grant multi-cellularity, which you could reasonably decline to do).

  15. David Marjanović says

    In a rewound tape, the brain could be anywhere…

    Most likely, on the cutting-room floor.

    LOL!

    (Not ROTFL. At least not on the cutting-room floor, ugh.)

    Only if you rewind it from early enough. Gould’s idea was to rewind it from the end of the Cambrian, when cephalopods already existed.

    This seems like as good a place as any to join my two favorite hobbies–webcomics and pretending to know something about science–with Dresden Codak’s alternate prehistory fanfiction.

    Bah. Try the Speculative Dinosaur Project. Warning: it’s seriously unfinished.

    Well, it might not be impossible, but it would be shocking if it happened. :)

    :-D :-D :-D

    If you think QM actually makes the first condition impossible (i.e. you think random effects at the quantum level would make macro-level events different over those 4 billion years)

    Absolutely. One cause of mutations is radioactivity, and radioactivity is truly random. The universe is not deterministic.

    Or are we really trying to convince the loons that evolution really is contingent, and that featherless bipeds with big brains won’t always emerge? Does anyone even really think they would?

    Yes, Simon Conway Morris for instance! That an idea is evidently wrong doesn’t mean nobody holds it.

  16. irenedelse says

    @ cypherpunks:

    Seconded! Let’s hear it for Eric Flint. (Plus, for fans of alternate history or political fiction, his novel 1632 is a must-read.)

  17. Sili, The Unknown Virgin says

    So, Sili, how does your brain work? Mine is a salty soup with lots of fatty tubes in it.

    Huh. And here I thought the name was a dead give-away.

    – the Siliconopolitan

  18. Feynmaniac, Chimerical Toad says

    The basis for Robert J. Sawyer’s Neanderthal Parallax is that the universe split into two about 40,000 years ago. One is our universe and the other is one in which we went extinct. In the other universe the Neanderthals became the dominant hominid.

    So rather than rewind the tape, let’s say the universe split in two millions (or billions) of years ago. What would life look like in the other universe?

    Also, what measures are we taking to defend ourselves against intelligent cephalopods with ray guns from an alternate universe? I have yet to hear Obama’s position on this issue.

  19. prosfilaes says

    The rewinding the tape would say something interesting. History-wise, there are a lot of historians who would give their right arm to rewind history in a computer back to 11/11/1917 and see if replaying it ever produced a stable German government. Is intelligent life really inevitable? Are there similarities in intelligent life? Are most of us mammals, or at least warm-blooded, or is there a huge range? What’s the mean duration of existence of an intelligent species? Are we above or below the mean for number of species erased?

  20. rrpostal says

    That ray gun is drawn completely incorrect also. Everyone know the l17-x model 3 has the compensator on the underside of the T-gauge and no longer needs the diversifier at the front which was replaced with an elongated hyper emulator a long time ago…unless we’re at the wrong place on the tape again.

  21. Hodor says

    Anyone here play “X-COM: Terror from the Deep”?

    It’s an early 90s PC strategy game where the Earth is under assault by a race of Aquatic aliens and genetically engineered weaponized sea creatures – including giant psychic jellyfish, “lobster men” and giant Nautili with heavy sonic cannons and near-impregnable shells.

  22. tonyrfleming says

    I’m surprised no one has yet mentioned the proposed descendants of cephalopods as depicted in “The Future is Wild”

    The swampus is a cephalopod that has evolved to live in shallow swamps and partly on land:

    and, millions of years later, its descendants include the megasquid, filling the niche of today’s elephants and the squibbon, a tiny tree-dwelling cephalopod that (though not mentioned in this clip) likely represents the re-emergence of sentience on Earth.