Where do eyes come from?
|December 9, 2007||Posted by idnet.com.au under Intelligent Design|
Richard Dawkins has often expressed faith in the ease of evolving eyes. It shows what strong faith he has in the power of RM and NS. Although he was completely wrong about this, he still has immovable faith in the power of Darwinian evolution. This is because his speculations rather than being based on evidence, simply depend on his very fruitful imagination.
Dawkins, Richard, Where d’you get those peepers?
Vol. 8, New Statesman & Society, 06-16-1995, pp 29.
“Serviceable image-forming eyes have evolved between 40 and 60 times, independently from scratch, in many different invertebrate groups. Among these 40-plus independent evolutions, at least nine distinct design principles have been discovered, including pinhole eyes, two kinds of camera-lens eyes, curved-reflector (“satellite dish”) eyes, and several kinds of compound eyes.”
As a result of recent findings, all of the evolution of the eye is pushed into the Precambrian where there are no data to confirm or deny the speculations.
From another source.
“The most impressive previously thought convergence in the evolution of the three image-forming eyes doesn’t exist in the eyes themselves but in the neural nets immediately behind the eye. All three eye types have a cross-linked network of amacrine and horizontal cells in order to sharpen their perceived images using a phenomenon called lateral inhibition. It now appears that the image-sharping network of amacrine and horizontal cells did not polyphyletically recur but rather was in place in the Urbilateria, the last common ancestor of all bilaterially symmetric animals. Arendt et al. did exactly the right thing in attempting to understand the evolution of any complex phenomenon. They looked at the vision system in a presumably primitive, incipient system, that of a polychaete, Platynereis dumerilii. Because polychaetes and vertebrates are evolutionarily far apart, they argue that any feature shared between them must result as feature of their common evolutionary heritage. Doing this, by itself, doesn’t prove that the LCA indeed was the true progenitor to both forms of eyes, ciliary (rods & cones) and rhabdomeric arthropod ommatedial), but when they looked in detail at the larval and adult eye forms of Pl\atynereis, they not only found both forms of eyes present, but also the vertebrate-type opsin (the bleachable protein that is the photon receptor) in the invertebrate’s brain. This and other information is more than enough to strongly suggest that the complex image-processing network that exists behind the retinal/rabdomeric surfaces in all three eye types, had only one origin in the history of the Metazoa and is very ancient.”