When you have made a bad call, hold on to it with all your might. From NEW SCIENTIST.
The eye was evolution’s great invention 06 May 2010
“Creationists have used the eye to make the “argument from design”. Evolutionary biologists say that the “inside out” vertebrate retina – leaves us with a blind spot – one of evolution’s “greatest mistakes”. Creationists have argue that the backwards retina has no problems providing excellent vision – and its structure enhances vision.
A study by (non-creationist) neurophysicists in Israel has found just that. Müller cells, which support and nourish the neurons overlying the retina’s light-sensitive layer, also collect, filter and refocus light, before delivering it to the light sensors to make images clearer.
Findings that coincide with the claims of creationists do not mean they have a point. It still creates a blind spot. It would make much more sense to put Müller-like cells in front of the sensors, with the wiring behind.
Rather than provide evidence in support of intelligent design, the new work is actually yet another example of evolution’s extraordinary ability to create workaround solutions to problems arising from earlier iterations. Kenneth Miller calls the Müller cells “a retrofit: a successful and highly functional adaptation made necessary by the original architecture of the retina, but a retrofit”. The eye’s structure, and the blind spot in particular, bears the unmistakable fingerprints of Darwinian evolution.”
Evolution gave flawed eye better vision 06 May 2010
IT LOOKS wrong, but the strange, “backwards” structure of the vertebrate retina actually improves vision. Certain cells act as optical fibres, and rather than being just a workaround to make up for the eye’s peculiarities, they help filter and focus light, making images clearer and keeping colours sharp.
Although rods and cones are responsible for capturing light, they are in a curious position. Hidden at the base of the retina, they are covered by several layers of cells as well as the bed of nerves that carries visual information to the brain. One result is a blind spot in our visual field, leading the vertebrate retina to be listed among evolution’s biggest “mistakes”.
In 2007 researchers reported that the glial cells act as optical fibres for the rods and cones. New findings suggest that sending light via the Müller cells act as light filters, keeping images clearnd that the intrinsic optical properties of Müller cells seemed to be tuned to visible light. The cells also seem to help keep colours in focus. Müller cells’ wide tops allow them to “collect” any separated colours and refocus them onto the same cone cell, ensuring that all the colours from an image are in focus.
However, Kenneth Miller, cautions that this doesn’t mean that the backwards retina itself helps us to see.”