Seeing with sea stars reported in ABC News in Science 27 August 2015. Scientists have known for many years that sea stars, or starfish, have simple eyes at the tip of each arm, but they always assumed that these merely enabled them to tell light from dark and orientate themselves towards darker regions in their environment. This is a useful function as they can find food on rocks and reefs, but not on the sandy bottom of the sea. Starfish only have a simple nerve net, rather than a proper brain, so scientists assumed they could not form an image of their surroundings. However, over the last few years research has shown that starfish can see better than we gave them credit for.
Ronald Petie of the University of Copenhagen removed the eyes from some crown of thorns starfish and placed them on the sand away from their reef home. Starfish with eyes headed straight back to the reef, but those without eyes wandered at random. He also recorded the electric signals from the eyes in different coloured light, and found they were most sensitive to blue light – a useful feature for a reef dwelling creature.
Petie commented: “Everybody thought starfish only used smell for orientation. But now we know this is not true for the crown of thorns starfish and one more species”.
The one more species is the blue sea star, Linckia laevigata, which was studied by Anders Garm at the University of Copenhagen in Denmark, and reported in ScienceDaily and New Scientist 5 July 2013. He carried out a series of similar experiments where he removed eyes from some starfish and left others intact, and then moved them off their rocky habitat and placed them onto the sandy bottom. The eyeless stars wandered around at random, whilst the one with eyes quickly went back to their reef home.
According to Garn: “From an evolutionary point of view it is interesting because the morphology of the starfish eyes along with their optical quality (quality of the image) is close to the theoretical eye early in eye evolution when image formation first appeared. In this way it can help clarify what the first visual tasks were that drove this important step in eye evolution, namely navigation towards the preferred habitat using large stationary objects (here the reef)”.
New Scientist commented: “The discovery is another blow to creationist arguments that something as complex as a human eye could never evolve from simpler structures”.
ABC, New Scientist, ScienceDaily
Editorial Comment: Now let’s get this straight. You pull the eyes out of a starfish and discover those that still have eyes see better than those without and this leads to the claim that this “discovery is another blow to creationist arguments that something as complex as a human eye could never evolve from simpler structures”.
Come on guys – such studies are no blow to creationists at all! We have no trouble explaining how the all-wise Creator gave sea stars ‘simple’ eyes that were most sensitive to the right kind of light, and could form a good enough image to enable stars to find their way home.
How about the evolutionists try explaining how “visual tasks” could drive a creature that did not have any vision at all to evolve eyes. The presence of blue light and the difference in light between the rocky reefs and sandy bottoms is not going to give any eyeless creature the genetic information needed to build even simple eyes, as well as connect them to its nervous system, and enable it to interpret the visual information collected by the eyes.
Furthermore, evolutionists don’t have a clue how the simple eye of a starfish later evolved by chance into the ‘complex eye’ and visual system of the human eye and brain. In both cases it makes far more sense that the Creator gave each creature with eyes the most appropriate eyes and brain for its needs. (Ref. vision, optics, echinoderms, sea stars)
Evidence News vol. 15 No.17
23 September 2015
Creation Research Australia