In my book The Cell’s Design, I illustrate how optimization indicates intelligent design. That is, when humans create objects and/or systems, they optimize their creations to handle trade-offs.
Likewise, optimization is a characteristic feature of natural biochemical systems. A few days ago I wrote about the optimization of protein structure and lifetimes; but this optimization is not limited to proteins. Along with DNA structure and a variety of metabolic processes, the genetic code also displays optimization. Check out the articles listed below for details on the optimization of the genetic code.