Millions of complex objects (cameras, adjustable wrenches, etc.) have been seen to come into existence under the direction/workmanship of intelligent designers. However, despite the often even greater complexity of biologiocal systems* we are often told that only unintelligent processes can be considered as "scientific explanations" for the origin of these structures.
My question is: What complex objects (analogous to biological systems or mechanical systems), has "unintelligent design" been observed to produce? And are these examples (if any) in themselves sufficient to merit the rejection of the consideration of intelligent biological design as science?
* For example the following is a brief description of what is involved in obtaining vision from one componet (photoreceptor) of even "simple" eyes (It can be verified by comparing it with a college level biology textbook). Keep in mind that photoreceptors are reqired for even the simplest eyes, and also the below treatment does not discuss the complexity of the sub-compontets named (ie: rhodopsin) etc. source (http://www.discovery.org/scripts/viewDB/index.php?command=view&id=51)
Here is a brief overview of the biochemistry of vision. When light first strikes the retina, a photon interacts with a molecule called 11-cis-retinal, which rearranges within picoseconds to trans-retinal. The change in the shape of retinal forces a change in the shape of the protein, rhodopsin, to which the retinal is tightly bound. The protein's metamorphosis alters its behavior, making it stick to another protein called transducin. Before bumping into activated rhodopsin, transducin had tightly bound a small molecule called GDP. But when transducin interacts with activated rhodopsin, the GDP falls off and a molecule called GTP binds to transducin. (GTP is closely related to, but critically different from, GDP.)
GTP-transducin-activated rhodopsin now binds to a protein called phosphodiesterase, located in the inner membrane of the cell. When attached to activated rhodopsin and its entourage, the phosphodiesterase acquires the ability to chemically cut a molecule called cGMP (a chemical relative of both GDP and GTP). Initially there are a lot of cGMP molecules in the cell, but the phosphodiesterase lowers its concentration, like a pulled plug lowers the water level in a bathtub.
Another membrane protein that binds cGMP is called an ion channel. It acts as a gateway that regulates the number of sodium ions in the cell. Normally the ion channel allows sodium ions to flow into the cell, while a separate protein actively pumps them out again. The dual action of the ion channel and pump keeps the level of sodium ions in the cell within a narrow range. When the amount of cGMP is reduced because of cleavage by the phosphodiesterase, the ion channel closes, causing the cellular concentration of positively charged sodium ions to be reduced. This causes an imbalance of charge across the cell membrane which, finally, causes a current to be transmitted down the optic nerve to the brain. The result, when interpreted by the brain, is vision.
(This thread is not about speculated claims of examples of "bad design" by evolutionists (such as the "inverted retina" http://www.icr.org/index.php?module=articles&action=view&ID=2476), of which the origin of was not observed by them, but rather about observation.)