106 thoughts on “A complex adaptation: the eye”

1. Rumraket,

   Considering the eye has been evolving for something like 700 million years, how common is “very common”?

   For Phoodoo this is circular reasoning as he does not accept that the eye evolved. It appears that complex eyes existed 500 million years ago.

2. Mung: ETA: From what I have gathered so far he is not presenting has argument as an IBE.

   I don’t see how it can be anything else. In so far as science is attempting to account for some presently observed facts that are thought to have arisen in the past, all we can do is make inferences to the best explanation and hopefully derive some testable predictions along the way.

3. phoodoo:
   And each “historical gradation” MUST have arisen by a lucky accident. Even though you hate to admit it, this is a part of the theory of unguided evolution.

   Considering that only a tiny fraction of the organisms that are born make it to reproduction, I don’t think that “lucky” is the right term to use.

   So, no. Lucky accidents are not part of the theory of evolution. It’s very wasteful stuff.

4. colewd: For Phoodoo this is circular reasoning as he does not accept that the eye evolved.

   I know he doesn’t accept it, but he’s implicitly accepting it happened in how he’s asking the question.
   I take him to be attempting a sort of reductio ad absurdum. Meaning assuming evolution is true, the eye must have required some amount of beneficial mutations that affect eye morphology and function to occur, and so that means that such beneficial eye-affecting mutations must have been “very very common”.

   But of course since phoodoo believes such mutations to be miraculously rare, or completely nonexistent and impossible (not sure which, but something along those lines), then by bringing up these questions he believes he’s showing the absurdity of evolution.

   But I’m saying the eye is thought to have evolved over quite a long period of time. So how “very very common” do those mutation need to be over that period of time for it to appear as absurd as phoodoo thinks?

5. Rumraket,

   Probability blindness is a common affliction. It’s not readily appreciated that the probability of a 1-in-a-billion event occurring within a billion trials is roughly the same as the probability of a 1-in-100 event in a hundred trials (and of course, it’s not 1!). Intuitively, people tend to imagine the latter as more likely to occur.

6. Mung,
   I think it is time to ask, such experts on the theme like Dr. Lents or Swamidass, if the eye can adapt beyond detecting one photon of light… Can it adapt to detect a half the photon, you think?