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.