Of Course Biology Exhibits Engineering Principles

Just as every human-designed system must conform to standard engineering principles — discovered by trial and error — in order to work efficiently, so must biological systems at all levels be replete with engineering principles in order to maintain proper fitness.

If we can expect engineering principles in biology...

If biology is rife with engineering principles, then why not use that as a predictive tool? 

Engineering principles are everywhere!

One of the observations that scientists have made about biology is that is it rife with engineering principles.  But of course we should expect such a thing.  Any man-made structure that we build would surely fail unless it is in accord with good engineering principles.  Why should anything less be expected of living systems?