Protein transport within a cell is irreducibly complex (Talk.Origins)
(Talk.Origins quotes in blue)
1. Despite the complexity of the system that Behe describes, protein transport need not be that complex. Some proteins direct their own secretion so that no transport mechanism is necessary.
The fact that some proteins do not need complex transport systems does not change the fact that the ones that Behe describes do. Furthermore it does not negate the fact such irreducibly complex systems can not develop naturally.
Certainly, other simple systems that could serve as precursors to vesicular transport should be possible.
This is baseless speculation, based on the assumption of Evolution. If Talk Origins had given even the smallest amount of evidence that these, simple precursors systems exist or even could exist, then they would have a point, but all they have is baseless speculation.
2. Many of the proteins involved in transport in eukaryote cells have molecular "ancestors" in bacteria. These molecules, the ABC transporters, serve in a much simpler system. If Behe is interested in the simplest system that accomplishes a function, why does he not even mention them?
The first thing to note is that these the ABC transporters are not the same proteins involved in transport in eukaryotic cells. The notion that they are molecular "ancestors" is nothing but Evolutionary speculation. It does not change the fact that protein transports in eukaryotic cells are irreducibly complex.
Talk Origins is actually Begging the question since Behe is arguing that the fact that protein transport in eukaryotic cells is irreducibly complex means that they could not have evolved from the ABC transporters. What Talk Origins needs to do is provide some evidence that the ABC transporters could evolve into eukaryotic protein transports, but they don't have any evidence to give.
This statement is bogus; it is based on flawed logic.
The statement includes the impossible demand that those who hold to the position that irreducible complexity implies design must disprove all possible evolutionary scenarios, even those that have not been invented yet. If sudden appearance of a complex system is not an "obstacle" to evolution, it seems the writer simply presumes that any large complex steps can happen by chance no matter how improbable.
Irreducible complexity is a hallmark of human design because when a humans produce something with a certain function they think through and provide the parts necessary to produce that goal. Human experience shows that objects with more than a certain amount of complexity imply it did not happen by chance and there was a designer involved. The whole structure of evolution is based on small stepwise changes from random chance that become fixed in the genome by natural selection. The point is that irreducibly complex systems do not fit the evolutionary structure.