Eye evolution problem reported in Current Biology published online 19 July 2018 doi: 10.1016/j.cub.2018.05.055.
A large and diverse group of invertebrates, the cnidarians, including jellyfish, corals and sea anemones, vary a lot in their ability to detect light and see their surrounding environment. Some have no eyes, some have eye spots and others have eyes with lenses. None have brains, but many have networks of nerve cells that can process information from eyes and/or eye spots.
Eye spots and eyes of varying complexity are often claimed to be different stages of evolution of the eye. A group of researchers from three universities in USA have carried out an extensive survey of cnidarians and studied the structure of any eyes or eye spots, along with their light sensing proteins, and light sensing behaviour. They wrote in their conclusion: “Rather than representing stages of a single line of gradual evolution, cnidarian eyes originated prolifically in the absence of a central nervous system, often using different opsin paralogs, different morphological building blocks, and/or different developmental pathways.” (Opsin paralogs are proteins similar to the light sensitive proteins in eyes.)
After drawing up a detailed evolutionary tree of cnidarians they concluded “Eyes Originated between 8 and 13 Times in Cnidaria” with “complex, lensed-eyes having a history separate from other eye types.” They claim their research provides “rich opportunities to address fundamental evolutionary questions.”
Editorial Comment: The scientists are correct in stating these finding do not fit the standard story of the gradual evolution of eyes from via individual light sensitive cells, then through cells clustered into eye spots and finally to complex eyes with lenses. However, their conclusion is faith, not science.
Much speculation has gone into the origin and evolution of eyes, ever since Darwin admitted that the evolution of a complex eye “with all its inimitable contrivances” seemed “absurd in the highest degree.” However, he went on to claim that it could happen by numerous gradations, where each gradation conferred some advantage and could be built up until a complex eye emerged. (Darwin, 1859, Origin of Species, p186) As this study shows, even using their own evolutionary tree, scientists cannot find such a gradation. Instead, they come up with a belief that that really is absurd in the highest degree – eyes evolved by themselves between 8 and 13 times.
This research is actually a rich opportunity to apply some common sense and recognise that the results are confirmation that the various cnidarians were created as separate, fully functioning kinds, each with the appropriate eyes or eye spots needed for it to function, just as Genesis tells us.
It is also a reminder the classification system of living things does not represent evolution and was never meant to. It is actually an intelligently designed method of organising our knowledge of living things, and is an extension of the task originally given by God to Adam to name animals.
Evidence News vol.18 No. 10
1 August 2018
Creation Research Australia
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