Nathan Lents: Bad Design of the Eye?

[swamidass (S. Joshua Swamidass)]

We are back to this conversation now. @NLENTS has begun to answer some of these questions.

The Point of His Book?

@swamidass

Nathan, you’ve been back and forth with Discovery about the “bad design” argument. Is “bad design” really the point of your book? Or is there something more subtle going on? How would you most carefully explain what you are getting at in these exchanges.

@NLENTS

have resisted saying that my book is written as an argument against ID because it wasn’t written that way. I believe that strange quirks are best explained by common descendent and so, implicitly, they argue against design insofar as design is offered as contrary to common descent. So, much of the content of my book, I believe, challenges ID, but that doesn’t mean that it’s written as a direct challenge to ID. If that were my goal, just about every sentence of the book would be written differently and I would have chosen different examples. Many good books refuting ID have been written. My book was written for an audience that already accepts evolutionary theory. Although it wasn’t written to challenge ID, the content of the book does pose challenges because, as you note, these quirks are rather easily understood from the point of view of common descent. Without that perspective, they are conundrums. (Has an ID-based explanation for the crazy path of the recurrent laryngeal nerve been offered? What about GULO? What about other pseudogenes?)

Two Questions:

But we are still left with a couple questions.

@swamidass

Nathan, I have several questions on the science here, but will start with one. Do we really know that the retina is “wired backwards”? It seems that the flipped between humans and octopi might just as likely be neutral. And I can even see some very plausible reasons the flipped orientation should be preferred (and I can explain).

It seems to me this wiring is most likely neutral. There is also a plausible hypothesis for why it might be beneficial to have it wired “backward.”

@swamidass

Nathan, several non-scientists on this forum have been asking about the evolution of the eye. This seems like a great way to begin this conversation too. We will save it for the end, but wondering if you can help map out how evolutionary biologists build the case for the evolution of the eye.

This is something that will be helpful to a lot of people, and I know that both @Patrick and @Michael_Callen have been wanting to learn more about this.