The Retina & Evolution.

DAWKINS DOWNED AGAIN as Erez Ribak and colleagues from Technion (Israel Institute of Technology) have produced detailed 3D scans of cells named Muller cells that are found in the retina, the light sensitive layer of the eye, and measured what happened to different wavelengths of light shone through them (see report in BBC News 7 March 2015). Muller cells are long cylindrical cells that span the thickness of the retina from front to back. Several years ago Ribak and colleagues suggested that these cells could act like fibre-optic cables conveying light from the front of the retina to the back layer, where the photo-sensitive cells are located. As such they could explain why the retina in vertebrates, including humans, seems to be arranged the wrong way around – “a centuries old puzzle” according to Ribak.

The light-guiding function was not initially accepted by other scientists, but now the Technion team have shown the Muller cells are just the right size and shape to “funnel crucial red and green light into cone cells, leaving blue to spill over and be sensed by rod cells - which are responsible for our night vision”. According to Ribak “This kind of clinched it”. There is still some scepticism about how the vertebrate retina ended up with the photo-receptor cells at the back. According to the BBC, “Mark Hankins, a professor of visual neuroscience at the University of Oxford, admires Dr Ribak’s work but is not convinced that the light funnelling phenomenon is the ‘driving force’ behind the reverse-wired vertebrate eye”. Hankins pointed out that the photoreceptor cells need to be close to a layer of pigmented cells at the back of the eye that clear away debris and worn out cell components and help supply light sensitive molecules. He also pointed out that the squid and octopus eye has the photoreceptors at the front, but it still has Muller cells. Hankins commented: “So Muller cells do plenty of important things other than perhaps functioning as light guides”. However, he did concede Ribak’s work showed how the different parts of the retina worked together to give good vision in both daylight and dim light. Link: BBC

ED. COM. Mark Hankins is correct – the light funnelling function of Muller cells was not a “driving force” to build the vertebrate retina. The vertebrate retina works because Muller cells already had this property. Furthermore, Muller cells do not work on their own. The retina works because all the retinal cells are in the right places. Hankins is also right about Muller cells having other functions, but that is just evidence of more clever design. In his book “The Greatest Show on Earth” Dawkins wrote that the retina was “the design of a complete idiot”. (Richard Dawkins, The Greatest Show on Earth, Bantam Press, 2009, pp353-354) We hope Richard Dawkins reads this BBC report and if so, we hope he has enough insight to see he owes God an apology for calling Him an idiot for the way the retina is constructed. Dawkins cannot even hide behind the fact his book was published in 2009 and the research described above was only reported this year. The light transmitting properties of Muller cells was first reported in 2007. (See our report “Eyes Badly Designed” Evidence News, 29 August 2007 here) Furthermore, we have known for many years about the other features described by Mark Hankins. Creation Research.