2016-02. Inside the Eye: Nature’s Most Exquisite Creation.

posted Feb 17, 2016, 1:27 PM by Alan Gould
By Ed Yong, National Geographic. For GSS Losing Biodiversity chapter 3. Excerpt: ...In his lab at Lund University in Sweden, Dan-Eric Nilsson is contemplating the eyes of a box jellyfish. ...the box jelly boasts 24 eyes, which are dark brown and grouped into four clusters called rhopalia. ...“When I first saw them, I didn’t believe my own eyes,” says Nilsson. “They just look weird.”  ...The fossil record tells us nothing about how sightless animals first came to see the world. This mystery flustered Charles Darwin. “To suppose that the eye, with all its inimitable contrivances ... could have been formed by natural selection, seems, I freely confess, absurd in the highest possible degree,” he wrote in Origin of Species. Creationists like to end the quotation there, with the great man doubting his own theory. But in the very next sentence, Darwin solves his own dilemma: “Yet reason tells me, that if numerous gradations from a perfect and complex eye to one very imperfect and simple, each grade being useful to its possessor, can be shown to exist … then the difficulty of believing that a perfect and complex eye could be formed by natural selection, though insuperable by our imagination, can hardly be considered real.” ...Nilsson...created a simulation that starts with a small, flat patch of pigmented light-sensitive cells. With each yearlong generation, it becomes a little thicker. It slowly curves from a sheet into a cup. It gains a crude lens, which gradually improves. Even under the most pessimistic conditions, with the eye improving by just 0.005 percent each generation, it takes just 364,000 years for the simple sheet to become a fully functioning camera-like organ. As far as evolution goes, that’s a blink of an eye....  http://ngm.nationalgeographic.com/2016/02/evolution-of-eyes-text