Posted: Jun 22, 2014 12:23 pm
Sorry to be such a purist, and refer to the OP topic, but something was left unsaid throughout this thread (mainly because I did not look at it for a long time):
Dawkins misunderstood vertebrate eye biology for a long time, and that made him vulnerable to criticisms along the lines of the OP linked creationist article. He had not understood that the selective traits of the vertebrate eye were very different from those of the cephalopod eye, because the latter was based on maximum sensitivity to light, sacrificing maintainability, whereas the former sacrificed some sensitivity, but achieved a much greater useful life in daylight, making it possible for some vertebrates to be sometimes much longer lived, and hence bigger, stronger, cleverer than most invertebrates, who are compromised by the "design" weakness of their retinae from that POV.
EDIT: A key cell type in the vertebrate eye is the retinal pigment epithelial cell. This is the real work-horse of retinal maintenance, as one of its key functions is the daily recycling of the hindmost opsin discs in its associated photoreceptor cell.
Dawkins misunderstood vertebrate eye biology for a long time, and that made him vulnerable to criticisms along the lines of the OP linked creationist article. He had not understood that the selective traits of the vertebrate eye were very different from those of the cephalopod eye, because the latter was based on maximum sensitivity to light, sacrificing maintainability, whereas the former sacrificed some sensitivity, but achieved a much greater useful life in daylight, making it possible for some vertebrates to be sometimes much longer lived, and hence bigger, stronger, cleverer than most invertebrates, who are compromised by the "design" weakness of their retinae from that POV.
EDIT: A key cell type in the vertebrate eye is the retinal pigment epithelial cell. This is the real work-horse of retinal maintenance, as one of its key functions is the daily recycling of the hindmost opsin discs in its associated photoreceptor cell.