How did those lifeless building blocks come together to form a living human? To illustrate the enormity of the challenge, consider the NASA space shuttle, one of the most complex machines ever devised. This technological marvel contains a staggering 2.5 million parts. It took teams of engineers years to design and put it together. Now consider the human body. It is made up of some 7 octillion atoms, 100 trillion cells, dozens of organs, and at least 9 major organ systems.a How did this biological machine of mind-boggling complexity and superb structure come to be? By blind chance or by intelligent design?