RE: The Human Eye: A Double Standard?
May 1, 2015 at 8:57 am
(This post was last modified: May 1, 2015 at 9:00 am by Anomalocaris.)
There have been a computer simulation - admittedly at this point computer model of actual evolution must be highly empirical and not based on the detailed genetic and biochemical foundations of biological function - which suggest that under strong selection pressure, it would take on the order of a million generations for descendants of a complex multicellular animal with existent light sensing cells to evolve complex focusing camera eyes. Rather less to evolve a compound eye.
If the average reproductive cycle of the descendants of such a creature is five years, then 5 million years is the ballpark length of time it might take for first human like eye to appear after environment begin to strongly favor creatures with acute vision.
Based on genetic and biochemical evidence, we know the first light sensitive cell that is the actual genetic and biochemical ancestor to all modern animal eyes is an very ancient algae. It is at least 2 billion years old and three times older that the oldest suggestive hint of a complex multicellular animal. So we know at the very beginning of complex animal evolution, way before Cambrian,the basic genetic and biochemical basis of the eye is already part of the shared foundations of the animal kingdom.
So all that remains is an environmental change which makes benefit of accurate vision greater than the cost of maintaining the specialized cells to facilitate it, and a million generations, however that long that might take, half million to five million years is not unreasonable, for one to become surprised not that the seemingly irreducibly complex eye climbed the ladder of complexity step by step to evolve, but rather if such a complex but beneficial eye had not evolved under the circumstances.
If the average reproductive cycle of the descendants of such a creature is five years, then 5 million years is the ballpark length of time it might take for first human like eye to appear after environment begin to strongly favor creatures with acute vision.
Based on genetic and biochemical evidence, we know the first light sensitive cell that is the actual genetic and biochemical ancestor to all modern animal eyes is an very ancient algae. It is at least 2 billion years old and three times older that the oldest suggestive hint of a complex multicellular animal. So we know at the very beginning of complex animal evolution, way before Cambrian,the basic genetic and biochemical basis of the eye is already part of the shared foundations of the animal kingdom.
So all that remains is an environmental change which makes benefit of accurate vision greater than the cost of maintaining the specialized cells to facilitate it, and a million generations, however that long that might take, half million to five million years is not unreasonable, for one to become surprised not that the seemingly irreducibly complex eye climbed the ladder of complexity step by step to evolve, but rather if such a complex but beneficial eye had not evolved under the circumstances.
