Darwin on Complexity
Biologist pointed out that there are several different ways that evolution can build irreducibly complex systems.
- Elaborate structures may evolve for one reason and the get co-opted for some entirely different irreducibly complex function. There is strong evidence that the 30 flagella proteins once played roles in a type of molecular pump found in the membranes of bacterial cells.
- Biologists have shown that direct paths to irreducible complexity are also possible. Suppose a part gets added to a system merely because the part improves the system’s performance. The part at this stage is not essential for function. But, because subsequent evolution builds on this addition, a part that was at first just advantageous might become essential. We add new parts like global-positioning systems to new cars not because they are needed but because they’re nice. No one would be surprised if eventually on board computers actually drive ours cars and that G.P.S. system are required in order to perform the function of driving the car.
