Tuesday, October 07, 2008

The eyes have it

Scientists have released video of the deepest fish ever filmed while alive at a depth of nearly five miles. At that depth there is no light. None. Nada. Zilch. It is as dark as the darkest cave.

And yet these fish have eyes. Unlike the Texas blind salamander which has non-functioning eyes embedded in its ehad, the eyes on Pseudoliparis amblystomopsis are clearly visible. As far as I can tell no one knows if Pseudoliparis amblystomopsis is actually blind or not, but either way it is yet another body-blow to the theory of "intelligent" design. Why give eyes, working or not, to a creature that lives where there is no light?

3 comments:

HomerNet said...

Don't be so quick to declare this a "body-blow" against ID, the astute debater would quickly be able to turn this back around on you with the same question. Why would eyes remain on a creature that lives where there is no light if evolution and natural selection were 100% dominant? After all, that's an awful lot of nerve endings on a single soft and squishy spot.

jacob said...

Homer - the creature continues to have "eyes" because of its evolutionary lineage. Vestigial structures can hardly be considered criticism of natural selection.

On the other hand, if there were no mutations in the evolutionary process and the species exists now as it always has, complete with non-functioning organs, well...you have to question how intelligent the "design" really was...

Ron said...

> Why would eyes remain on a creature that lives where there is no light if evolution and natural selection were 100% dominant?

Because eyes provide a huge survival advantage in environments where there is light, but only a moderate disadvantage where there is none. Therefore, the evolutionary pressure to have eyes where there is light is enormous, whereas the evolutionary pressure to get rid of them if you are descended from ancestors who had eyes but you now live in the dark is weak. So unnecessary features, once they have evolved, tend to stick around for a long time even after they have outlived their usefulness.

Nature us actually chock-full of this kind of thing. They are called vestigial structures. The only reason that the eyes of Pseudoliparis amblystomopsis are remarkable at all is that the absurdity of their having been put there by an intelligent designer is, quite literally, staring you in the face. (Most vestigial structures are hidden -- because having an extra unneeded feature on the outside of your body where it can, for example, be seen by predators is much more of an evolutionary disadvantage than having one safely tucked away on the inside.)

> After all, that's an awful lot of nerve endings on a single soft and squishy spot.

This is a common misunderstanding. Evolution does not optimize, it satisfices. It only produces designs that are "good enough" to reproduce here and now. And it produces those designs under the constraint that the next generation can only have small, incremental changes from the previous one. You're probably right that those eyes are now a net disadvantage in the current environment. If you are, then you can come back in a few million years and those eyes will almost certainly have vanished, or at least receded from view as they have in the Texas blind salamander and the naked mole rat.