The article linked to above describes a most interesting creature:

The sea mouse, or Aphrodita, has spines that normally appear deep red in colour. But when light falls on a spine perpendicular to its axis, stripes of different colours appear - strong blues and greens.

The most remarkable feature about the spines is that, not only do they have a highly specialized internal structure giving rise to this behaviour, but they also handle light "with almost 100% efficiency." This is because the light emitted by the spines to create these stripes of color acts as a defense mechanism - the high efficiency is required, because:

"Below a few hundred metres little light reaches the ocean floor, so for the spines to be effective they must make best use of every scrap of light available," said co-researcher Dr Andrew Parker of the University of Oxford.

Of course, all this raises the question - How'd evolution produce THAT?

It couldn't have developed gradually, because for the spines to be effective, they'd have to have popped into existence fully formed, or at least nearly so, enough to get a pretty high efficiency of light transfer. There is, from what the article says, a very high level of complexity needed in the spines to even get close to having the properties observed, and no survival benefits could be realized until they exist - what benefits could accrue from emitting a dim light in one of the darkest places on earth, other than to attract predators?

This seems to me to be a necessary intermediate form - a being which emitted light, but not a specific form of light (or the wrong specific form of light) - and such a form would be doing the equivalent of saying "eat me" to any predators in the area. Of course, once it had somehow made it past that point, it would have a nice defense mechanism... But wouldn't be easier to just evolve a nice hard carapace, or an ability to swim quickly?

If anyone has an explanation, I'd be quite interested in hearing it.

Responses to date:
  • "Because evolution doesn't happen only gradually. It often occurs catastrophically, shockingly, huge rapid changes. When unsuccesful we call them monsters. When they work, they are a new species."

I used "emit" in what I felt to be a wholly appropriate sense - that the spines, after performing some various photonic operations upon incoming (faint) light, emitted a brighter, more colorful reincarnation of the same light. I make no claims that said light emitted is created by the creature in some sort of bioluminescent manner, but meant only that it radiated some form of visible radiation in a manner more intense than it received other, similar forms of visible radiation.

Apparently this was not the clearest use of the word. I apologize - hopefully this postscript will clear things up.

I think Gorgonzola overestimates my subtlety. I do agree with several of his points - I did make an assumption about the role of the creature's lights (as defense), as well as about a few other things.

As to whether this is a "disingenuous attempt to discredit natural selection", I can't say - Certainly, part of my goal in writing this was to make people think about the likelihood of wholly new structures arising in sea animals, but I was also pretty curious as to how such a structure was said to have arisen.

My curiosity remains, of course. Why not bioluminescence? That's been done in a number of other deep sea creatures. It's certainly easier to evolve - it's a simple chemical reaction in certain cells of the creature's body, whereas this is quite a bit more complex. Why would the creature evolve such a complex solution to a problem where there is a clearly simpler (to arrive at), more reliable method?

And as for my "confusion" of evolution and natural selection, my definitions of them are this:

  • Evolution - The naturally occuring, spontaneous creation of new species from older, pre-existing (and generally simpler) ones. Generally not reversible - one species generally doesn't "devolve" back to the species it originated from. Example: Mice evolving from rats, because rats couldn't get to some food supplies, since they were too big. (Just an example - I make no claims to its veracity or accuracy.)
  • Natural Selection - The naturally occuring, spontaneous culling of certain genotypes of a given species that are less conducive to survival. Example: Dark moths becoming more common than light moths in summer, because light moths stand out against the darker backgrounds in summer. The situation reverses in winter.
  • Species - A group of animals with similar characteristics and genetic makeup, with the possibility of inter-breeding. Example: Dogs. Even though Great Danes and Chihuahuas don't ever breed (that I know of), their genetic material is similar enough that a viable offspring could be produced... Presumably with a Great Dane bitch, due to size issues.

You're in a minefield: Phrase your question more carefully in the future.

Although this question is can be a legitimate scientific inquiry into the genesis of a peculiar trait of a particular creature, one must always be wary when the word "evolution" appears as the topic of a discussion.

Questions like the title of this node are often disingenuous attempts to discredit natural selection, a theory which has been the target of certain groups who claim it attacks their "faith". They misapply the label "evolution" to it, which can mean a whole host of other things. Sadly, or perhaps amusingly, whenever such people try to "disprove" natural selection and thus "prove" the object of their "faith", they only demonstrate the weakness of that faith.

Most perplexingly, they do this even though natural selection does not rise or fall on the accuracy or inaccuracy of any religious beliefs. This unreason often leaves reasoning people nonplused: How do you answer madness?

I am not going to attempt to characterize which category the first writeup falls into; I sincerely hope it's the former.

However, the writeup contains some misstatements, as well as flaws in the writer's reasoning.  I am far from being a marine biologist, but I think I can point the flaws out and offer some explanations of how the sea mouse got its spines that are at least plausible.

We have been pointed to a news story that describes unusual characteristics of spines of the "sea mouse" Aphrodita an invertebrate that feeds on the bottom of the ocean.  That is, when light strikes the spines from one angle, they appear one color; from another angle, they appear another color.  The article is really about the possible applications of the spines' properties to photonics.

We are led to believe that the sea mouse lives in the deep (Benthic) ocean, where there is no light to be had.  The creatures do appear at depths of 2000 meters, however, species of aphrodita occur, according to, starting just below the intertidal zone (10 meters or greater), where things may be dim, but certainly not dark.

We are led to believe that the sea mouse emits light.  I can find no source that says that the sea mouse is bioluminescent.  Indeed, the cited article talks about the refractive properties of the spines.

We are led to believe that emitting light or having distinctive coloration serves only to attract predators.  Nature is full of examples where these are used:

  • as a means of communication
  • as a warning to predators of a creature's toxicity
  • as bait to the creature's prey
  • as a decoy, offering less vital parts of a creature for predators to eat.
I have no idea, of course, whether any of these apply to the sea mouse. Suffice it to say, though, that these other creatures stand out and aren't extinct. In fact, bioluminescence appears to be the rule in the deep sea, rather than the exception.

When we are asked, "what benefits could accrue from emitting a dim light in one of the darkest places on earth, other than to attract predators?", we must answer back, "why would emitting a dim light attract more predators than emitting a bright light?"

We are led to believe that the optical properties of the spines have to be a selection advantage.  They may, and then again they may not. The spines' iridescence comes from their peculiar structure, hexagonal columns of protein secreted by cells on the worm's body.  It is possible that this structural property of the spines is the primary benefit to the creature, and any iridescence is just a side effect.

Finally, we are led to believe that the spines' optical properties have to be perfect in order to be useful.   If we are talking about the structural advantage discussed in the last point, this requirement for immediate perfection falls flat on its face.

However, let's really stretch, assume that that point is inoperative, and that the spines' optical properties have some use.  Let's assume we need a traditional "gradualistic" explanation.

We cannot assume that the creature originated in the deep ocean and has remained there since. If the creature originated in the intertidal zone, where there is some light, an "intermediate form" (a lesser amount of iridescence from the same amount of light) might have a beneficial effect in a zone where there is more light.  As the creature spread into the deeper ocean, where there is less and less light, later generations would be selected for more and more efficiency of refraction.

Enough of this, I think you get my point:  It is entirely possible for the sea mouse to have arisen via natural selection.

As much as I don't believe in creationism, my faith in evolution has been shaken since I started asking about the evolution of meiosis. As far as I can fathom it could not have happened. I can go along with Gaia controling the temperature of the Earth, molecules hazardly coming together to form the first life, and that life evolving into the asexual creatures we know today, but this doesn't help me understand where I, a (potentially) sexually reproductive creature, came from.

The thing with evolution is that all grand transformations must happen with many increments, as in this explanation (click the link) of the eye because of small changes in dna due to radiation, novel patterns happening due to sexual reproduction (after the development of meiosis), or other imperfections in the reproductive process. With meiosis there aren't enough small steps to fill the gaps.

I've heard theories that this started as well by chance, single celled organisms bumping into each other randomly (or due to cannibalism according to one theory) forming new daughter cells, the process became more sophisticated and developed into sexual reproduction. Unforturnately, nowhere in this model is there an explanation of the first sperm or ovum. Assuming this process could in fact create new organisms, these new organisms would not be more prone to dividing into cells with only half the chromosomes.

Another theory, this one may be original, would have primative sexes develop as an intermediate step by simple random radiation. Without sex to bind them together they could simply continue to evolve divergently. For the sake of theory, even create a hypothetical symbiosis that keeps them in the same ecological community.

Or perhaps the sex cells were self-sufficient, that is that they could live on their own for long periods of time while looking for another sex cell to unite with. This way space and time become less of a problem, and the cell could even search for an ideal environment for the union rather than the parent organism being responsible for creating it, thus sidestepping the whole sophisticated reproductive organ debate.

Another of my potentially orginal theories suggests that sexual reproduction in its primative beginings occured in hermaphrodites. But it would take further theorizing to get from mitosis to here, and from here to modern dual sex system.

Essentially, the problem lies in the physical act of creating a sex cell, ie how did the first primitive sperm evolve?

This is the question I want religious nuts to start asking, to make the egghead work harder for a solution. Why, because I want answers (even if it means giving the creationists a leg up).

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