Not only can we detail the steps in a plausible path, we can actually model how long the process takes.
Sweidish zoologists Dan Nilsson and Susanne Pelger developed a computer model that starts with a simple light sensitive eye spot. Using conservative assumptions about how much variation there can be from one generation to the next in all the parts of the animal around the eye spot, as well as conservative model of how changes in each part might effect the ability of the animal to procreate, the conclude that evolutionary pressure can go from a simple eye spot to a essentially complete complex eye with lenses, focusing muscles amd differentiated light sensing retina in well under half a million generations.
Based on the observation that modern cousins to animals in which we think eyes first developed have life cycles that is essentially annual (1 year = 1 generation), they concluded that starting from simple light sensing spot and a strong evolutionary advantage to being able to shape behavior based on clear optical image of the environment, evolution can produce a complex eye with lenses and focusing muscles in well under a half million years through a process where each step, whether creationists would call that 0.0001 eyes, or 49% of an eye, or 87% of an eye, offers incremental advantage to the step that came before.
In other words, not only did nature have enough time to evolve the complex eye one thousand times from scratch since the first known eye bearing animal in the fossil record, but also there was more than enough time at the very beginning of Cambrain explosion for the eye to evolve, such that as far as would make no difference in the scheme of fossil dating, fully evolved complex eye could explode onto the animal world without any discernable pre-cambrian antecedant.
Sweidish zoologists Dan Nilsson and Susanne Pelger developed a computer model that starts with a simple light sensitive eye spot. Using conservative assumptions about how much variation there can be from one generation to the next in all the parts of the animal around the eye spot, as well as conservative model of how changes in each part might effect the ability of the animal to procreate, the conclude that evolutionary pressure can go from a simple eye spot to a essentially complete complex eye with lenses, focusing muscles amd differentiated light sensing retina in well under half a million generations.
Based on the observation that modern cousins to animals in which we think eyes first developed have life cycles that is essentially annual (1 year = 1 generation), they concluded that starting from simple light sensing spot and a strong evolutionary advantage to being able to shape behavior based on clear optical image of the environment, evolution can produce a complex eye with lenses and focusing muscles in well under a half million years through a process where each step, whether creationists would call that 0.0001 eyes, or 49% of an eye, or 87% of an eye, offers incremental advantage to the step that came before.
In other words, not only did nature have enough time to evolve the complex eye one thousand times from scratch since the first known eye bearing animal in the fossil record, but also there was more than enough time at the very beginning of Cambrain explosion for the eye to evolve, such that as far as would make no difference in the scheme of fossil dating, fully evolved complex eye could explode onto the animal world without any discernable pre-cambrian antecedant.
