[quote=bobl]
Try evolving an eye. The eye is useless unless the entire infrastructure is complete. All the intermediate forms of that are useless. Why would any animal undergo the baggage of thousands or millions of years of useless intermediate forms in the hope that someday a developing component would become useful? The whole thing is so illogical, it is repulsive to me. But take God out, and I guess that’s your only choice.
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I am a biologist, and I can tell you that the above (which I somehow missed) is total BS. The problem is that you are starting with the end result, and then demanding that evolution work backwards to nothing. As if somehow the human eye were the pinical of evolution and its end ‘goal’ from the beginning. Considering that is how many people who perscribe to this kind of nonsense feel, that they are the end all be all of the world blessed by the almighty himself, it is understandable. But it just isnt true that the human eye is in anyway special.
The point of an eye is to precieve light. Even damaged human eyes may still able to achieve this. This perception of light is critical to many body functions, most especially reproductive systems. Often it is changes in the amount of light observed that tell animals to begin or end mating seasons. These early “useless” eyes are actually extreamly critical in maintaining the animal, espeically in mammals. (Those of you with SAD may be experiencing exactly this kind of hormonal change.)
Early “eyes” were mearly to detect light. Perhaps the animal wanted to move toward areas where sunlight would warm the water, or where photosynthesis could be performed, or maybe away from the light so it couldnt be “seen” by preditors. It isn’t hard to imagine an arms race of preditor vs prey breaking out, where preditors keep developing better and better eyes to detect prey, and prey developing better and better eyes to avoid being eaten. This can be seen today in the fact that preditors have eyes close together on the front of their face, which allows for better depth preception while prey have eyes that are further spread out on the skull to allow for the max field of view.
If you are unable to imagine this war, it works by natural variations within populations. One prey animal who happens to have slightly wider field of view survives attack while its neighbor, who didnt, doesnt. Obviously wider eyed animals mate more since they are the only ones around anymore, and the population evolves. Then the preditor, hungry because everyone sees them, evolves better eyes (over generations) which allow them to see the prey from farther away and approach better. The ones who have better eyes eat, those that dont die, and the preditor population evolves. Each step is small, random, and totally reversable if situtations warrent it. Welcome to evolution.
Given enough time, and the right set of stimuli (ice age, preditor,…..) evolution could develop something for just about any need we can think of. It just may not be in the form you want it to be in.
