Gradualism in Eye Evolution

Here's one ID proponents won't like:

Biologists at the University of California, San Diego have discovered that the presence of a key protein in the compound eyes of the fruit fly (which glow at center due to a fluorescent protein) allows the formation of distinct light gathering units in each of its 800 unit eyes, an evolutionary change to an “open system” that enabled insects to make significant improvements in visual acuity and angular sensitivity. In contrast, beetles (shown surrounding the fruit fly), bees and many mosquito species have the light-gathering units fused together into a “closed system.”

But this gets to the real point:

Charles Darwin was so enamored by the intricate complexity of the eye that he wondered how it could have evolved. “These results help illustrate the beauty and power of evolution and show how ‘little steps’—like the presence of a single structural protein—can so spectacularly account for major changes in form and function,” said Charles Zuker, a professor of biology and neurosciences at UCSD and a Howard Hughes Medical Institute investigator, who headed the research team.