Jellyfish eyes

| 39 Comments
cubozoan eyes

This very strange object was peering out at me from the cover of last week's Nature…and "peer" is exactly the right word. Those are some of the eyes of a cubozoan, a box jelly, of the species Tripedalia cystophora. These eyes have some very peculiar features, and show that once again nature trumps the imaginations of science fiction artists.


Continue reading "Jellyfish eyes" (on Pharyngula)

39 Comments

PZ Myers alleges:

The rhopalium shows the upper and lower lens eyes flanked by two pairs of simpler eyes. … the two dark smudges on each side in the above picture are simple pigmented pits with photoreceptors in the center.

This is horsepookey. I have it on good authority from Dr. Behe that no ‘primitive’ eye, lacking any component of my eyeball, could ever be of any use, or evolve.

This is fascinating. Research has shown how the eyes/cilium form a sensory/motor unit without the need for a brain See

A simple visual system without neurons in jellyfish larvae

See also Cubozoan jellyfish: an Evo/Devo model for eyes and other sensory systems

Let’s hear how ID explains this.… Oh I forgot, ID fully accepts that

Johnson Wrote:

“Evolution is the most plausible explanation for life if you’re using naturalistic terms, I’ll agree with that.”

So all that remains is filling the gaps in our knowledge with appeal to the supernatural. Back to the middle ages…

Some questions:

1) Aren’t these Box Jellyfish supposed to be the *really* dangerous? Like, even more dangerous to humans than the dreaded Portugese Man-Of-War?

2) I remember reading in an old Nat. Geo. that there doesn’t seem to be any evidence that the Box Jellyfish has any sort of “brain” or nervous system…at least not as we would usually define it. So what coordinates its movement?

So Johnson believes there is evidence that god shaped (“designed”) human life, if only science would look for it…

Wow, how does he suggest we look for this supernatural influence? - by the very essence of supernatural means beyond nature and as such is not observable or measureable…

rampancy Wrote:

I remember reading in an old Nat. Geo. that there doesn’t seem to be any evidence that the Box Jellyfish has any sort of “brain” or nervous system … at least not as we would usually define it. So what coordinates its movement?

Your problem, rampancy, is you’re myopically restricting yourself to naturalistic explanations. Who says the jellyfish’s movements aren’t coordinated by a supernatural agency?

Off-topic: Early Earth chemistry

Building a Better Biosphere

Thirty years ago, geochemists took away the primordial soup that biologists thought they needed to cook up the first life on Earth. Now, atmospheric chemists are giving it back. They’re showing that the early Earth could have held onto much more of its volcanic hydrogen, a key ingredient in the recipe for making the organic compounds that may have led to the first life. …

2) I remember reading in an old Nat. Geo. that there doesn’t seem to be any evidence that the Box Jellyfish has any sort of “brain” or nervous system … at least not as we would usually define it. So what coordinates its movement?

I don’t know. You’d have to ask its cousin, Dembski.

(sorry, toejam, the devil made me do that.)

Geesh. Ask a stupid question… :)

(I guess it’s off to Google and WoS for me…)

PvM Wrote:

Back to the middle ages …

Typically modern appeal to ‘progress’.

So how would you define “progress” then, Finley?

Is the abandonment of centuries of achievement and development in the sciences to a return to the Fundamentalist Christian-based Arguement from Incredulity “progress” to you?

Perhaps you don’t consider the development of vaccines against Polio as a sign of “progress”…I’m sure that you’d much rather see the abandonment of traditional “materialist” medicine in favour of Benny Hinn-style Faith Healing, right?

But what good is half a… ah, hell, creationists still suck.

At the bottom of PvM’s line about the Middle Ages (read “Dark Ages”) is the belief that any appeal to a divine cause in nature is contrary to reason.

Needless to say (or at least it should be), that’s a hard position to defend.

However, since I meant my response as a hit-and-run, and have no intention of hi-jacking this thread for a discussion of “religion and science,” I’ll leave it at that.

“However, since I meant my response as a hit-and-run”

oh, no, hit and run tactics have nothing to do with hijacking threads.

get lost, finley.

The part of the paper I found most interesting was that on the sensory stalk/bulb there were actually 4 kinds of eyes including the major evolutionary landmarks identified years ago by Nilsson.

http://www.nature.com/nature/journa[…]57a-f2.0.jpg

Sorry there are no images in comments. Maybe PZ will add it to the OP.

@rampancy:

“1) Aren’t these Box Jellyfish supposed to be the *really* dangerous? Like, even more dangerous to humans than the dreaded Portugese Man-Of-War? “

IIRC, there are quite a few species that are categorized as “box jellyfish”, including the one known as the “sea wasp” (from Australia), which is probably the one you are thinking of. I don’t think all box jellies are toxic to humans, but that one most assuredly is; and yes, it can be considered more dangerous than a man-o-war.

http://www.ncbi.nlm.nih.gov/entrez/[…]opt=Citation

2) I remember reading in an old Nat. Geo. that there doesn’t seem to be any evidence that the Box Jellyfish has any sort of “brain” or nervous system … at least not as we would usually define it. So what coordinates its movement?

well, no brain or complex ganglia, but certainly a nervous system:

http://faculty.washington.edu/chudler/invert.html

“the jellyfish has a nervous system characterized by a series of interconnected nerve cells (a nerve net). The nerve net conducts impulses around the entire body of the jellyfish. The strength of a behavioral response is proportional to the stimulus strength. In other words, the stronger the stimulus, the larger the response. Some jellyfish (for example, Aurelia) have specialized structures called “rhopalia”. These rhopalia have receptors for:

light (called ocelli) balance (called statocysts) chemical detection (olfaction), touch (called sensory lappets)”

hope that helps.

cheers

2) I remember reading in an old Nat. Geo. that there doesn’t seem to be any evidence that the Box Jellyfish has any sort of “brain” or nervous system … at least not as we would usually define it. So what coordinates its movement?

Jesus.

2) I remember reading in an old Nat. Geo. that there doesn’t seem to be any evidence that the Box Jellyfish has any sort of “brain” or nervous system … at least not as we would usually define it. So what coordinates its movement?

“Christ is indispensable to any scientific theory.”–William Dembski

Finley Wrote:

At the bottom of PvM’s line about the Middle Ages (read “Dark Ages”) is the belief that any appeal to a divine cause in nature is contrary to reason.

Needless to say (or at least it should be), that’s a hard position to defend.

Not at all, I am merely stating that appeal to divine cause in science is a reversal to the God of the Gaps.

“Not at all, I am merely stating that appeal to divine cause in science is a reversal to the God of the Gaps”

hmm, and here i thought appeal to a divine cause “in science” was a bit of an oxymoron?

moreover, how is appeal to the divine a reversal of god of the gaps?

you get more confusing every day, finley.

er, sorry, i see that it was PvM that posted that!

are you sure that’s what you wanted to say?

now i’m really confused.

I’ve never minded the phrase ‘God of the gaps’. If there is a ‘gap’, i.e., an unexplained phenomenon, it needs to be filled. If natural causes cannot explain an observed fact, it is reasonable to consider alternative explanations, miracles.

What justifies the insistence that every unexplained phenomenon, present and future, will be explained by natural causes? I suspect it’s an inductive argument of the sort “Every unexplained phenomenon in the past has been explained by natural causes, therefore, .…” But the premise of this argument is false; there are many phenomena that were unexplained by natural causes in the past and remain unexplained by natural causes today. Such an induction, then, would have to use the weaker premise “Some unexplained phenomenon in the past has been explained by natural causes.” But what is supposed to follow from that?

Michael Finley Wrote:

I’ve never minded the phrase ‘God of the gaps’. If there is a ‘gap’, i.e., an unexplained phenomenon, it needs to be filled. If natural causes cannot explain an observed fact, it is reasonable to consider alternative explanations, miracles.

I’m reminded of the practice at the Oscar ceremonies of having people poised in the audience to quickly fill the seat(s) of award winners so that when the cameras pan the audience no empty seats will be seen. Of course, no one cares if there are empty seats, and reasonable people, upon seeing empty seats, would deduce the fact that the seats were temporarily vacated by award winners. The God of the Gaps is a similarly absurd placeholder and He must get pretty tired of having to relocate when more reasonable explanations come along.

Jim Wynne Wrote:

The God of the Gaps is a similarly absurd placeholder…

If asserting and justifying a conclusion were the same, then everyone would be clever.

Michael Finley Wrote:

What justifies the insistence that every unexplained phenomenon, present and future, will be explained by natural causes?

Who insists that? That’s a strawman if I ever saw one. What justifies the assumptionthat gaps not presently explained by natural phenomena won’t be? Do you have evidence to the contrary that you’re not sharing with us, or are you just “clever beyond measure”?

Jim Wynne Wrote:

What justifies the assumption that gaps not presently explained by natural phenomena won’t be?

I don’t make such an assumption. I readily admit the possibility that every unexplained fact will be explained by natural causes. Can you admit that some unexplained facts may never be explained by natural causes?

In the absence of an explanation, why is an unknown natural explanation a more plausible possibility than an unknown miracle?

Finley just needs to find his personal god hiding somewhere in the objective universe. And Finley is intelligent enough for this to be a significant problem. After all, his god doesn’t DO anything tangible. For some, perhaps Finley’s god ‘answers’ prayers, but never does so with any useful specificity. Anyone who thinks otherwise should visit a casino, and watch whole roomfuls of people praying their cojones off, while the house collects a precisely calculable percentage day after day.

There are two explanations for the unexplained. Science’s version (unknown at this time) and Finley’s version (goddidit). And day by day, thanks to the efforts of an army of investigators, the unknown shrinks and therefore so does Finley’s god. Is there any wonder Finley is desperate to “see” the supernatural wherever the alternative isn’t (yet) stone obvious? Is it any wonder that whenever anyone points out that no working scientific theory has ever required the slightest lick of magic, Finely seems to pop up to shout methodological naturalism? And is it any wonder that Finley owes his own education, his health, his occupation, and his ability to bray his insecurities here to the very principles he is trying to distort as his faith requires? Dropping the supernatural (still undetected) in favor of the natural has in a few short centuries changed Finley’s world in all respects – probably including buying him the time to struggle against it.

I’ve never minded the phrase ‘God of the gaps’. If there is a ‘gap’, i.e., an unexplained phenomenon, it needs to be filled. If natural causes cannot explain an observed fact, it is reasonable to consider alternative explanations, miracles.

OK, that settles it. I won’t be reading any more Finley comments.

Flint,

That’s the worst piece of psychology/sociology I’ve ever read. It’s a poor substitute for a straight-forward answer to my question. Let me try again.

There are two explanations for the unexplained. Science’s version (unknown at this time) and Finley’s version (goddidit).

What reason have you to prefer one over the other?

because one method has shown time and time again to produce useful results once technology catches up with “the gaps” so they can be tested, while the other has produced… nothing.

simple as that, finley.

Now, that’s unfair, Sir Toejam. It’s managed to get some very nice buildings put up (by us imperfect mortals, mind you), and it’s also produced a great deal of writing, music, and hysterics.

What reason have you to prefer one over the other?

Unless you have some positive evidence that you’d like to share with the rest of us, one is a simple statement of fact, while the other is baseless conjecture.

Finley Wrote:

I’ve never minded the phrase ‘God of the gaps’. If there is a ‘gap’, i.e., an unexplained phenomenon, it needs to be filled. If natural causes cannot explain an observed fact, it is reasonable to consider alternative explanations, miracles.

Why is it reasonable? And why is it that ID is looking for evidence for God in our ignorance? Why not accept the ‘we don’t know’ instead as a far more reasonable position. That’s what science does. It’s almost an insult to God that ID insists that we look for Him in areas we do not understand. History has shown this to be a very poor position.

So can you explain why we should accept that God lives in the gaps of our knowledge, a position which is both historically quite unsuccessful, and which basically is an argument from ignorance. Why not admit that ‘we don’t know’?

Re “and it’s also produced a great deal of writing, music, and hysterics.”

hysterics?

Re “that no working scientific theory has ever required the slightest lick of magic,”

A thought: once a phenomena can be consistently observed (or produced), it would at that point (as likely as not) then get labeled as “natural”.

As for whether one should “prefer” an unknown “natural” explanation over an unknown “supernatural” (whatever that is) explanation, IMO the key word in both is “unknown”, and if it’s unknown it’s unknown. The distinction of “natural” vs. “supernatural” is irrelevant until something about it becomes known. That’s just by two cents worth on that.

Henry

Michael Finley Wrote:

What reason have you to prefer one over the other?

Just off the top of my head, which I have a habit of using for something other than fatuous, self-absorbed rumination, how about those dirty methodological naturalists who had the audacity to believe that mental illness has a somatic basis, and is not caused by demon possession? I think that if I were one of the millions of paranoid schizophrenics who have gotten at least some of their lives back as a result of people preferring natural causes over gapgod I would have a tendency to prefer natural causes.

Looking for supernatural causes is unreasonable.

If the link between a cause and an effect were reasonable, it would, in fact, be a natural cause and not a supernatural cause.

“Looking for supernatural causes is unreasonable.”

Tho infinitely easier, and ANYONE is qualified to do it!

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There are two explanations for the unexplained. Science’s version (unknown at this time) and Finley’s version (goddidit).

What reason have you to prefer one over the other?

I’m curious, Finley —– are you under the assumption that the two are mutually exclusive, and that we therefore must choose between one and the other?

If so, why do the vast majority of Christians, worldwide, NOT see them as mutually exclusive, and why is YOUR religious opinion on the matter any better than theirs, other than your say-so.

No need for you to answer, Finley – the question itself makes the point with crystal clarity. And I do understand that you are lethally allergic to answering direct questions (as are *all* IDers).

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This page contains a single entry by PZ Myers published on May 16, 2005 11:01 AM.

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