Michael Behe, a biochemist currently teaching at Lehigh University, coined a term for describing the design phenomenon inherent in molecular machines such as the bacterial flagellar motor -- "Irreducible Complexity" -- "a single system composed of several well-matched, interacting parts that contribute to the basic function, wherein the removal of any one of the parts causes the system to effectively cease functioning." 1
Like a mechanical motor, each part in the flagellar motor is absolutely necessary for the whole to function. Therefore, I couldn't logically deduce any naturalistic, gradual, evolutionary explanation for the existence of a bacterial flagellum. Besides, no one would expect an outboard motor, whether mechanical or biological, to be the product of a chance assemblage of parts. Outboard motors are designed and engineered!
Of course, I just picked one example. The bacterial flagellum is only one among many thousands of intricate, well-designed, molecular machines. Furthermore, take these same principles of design and "irreducible complexity" and apply them to marvels such as the human eye, ear, heart, lungs and brain. Seriously, how can we logically explain the gradual and random development of these complex systems?
What about the human heart? It's a miraculously efficient and durable hydraulic pump that no engineer could dream of producing…
What about the human brain? It's a legitimate computer system, 1,000 times faster than a Cray supercomputer and with more connections than all the computers, phone systems and electronic appliances on the entire planet...2
Wait. I remember Darwin saying something about this…
If it could be demonstrated that any complex organ existed which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down. 3
OK, using Darwin's own words, let's dig in further and look at one of these complex organs - the human eye…
1 Michael J. Behe, Darwin's Black Box: The Biochemical Challenge to Evolution, Simon & Schuster, 1996, 39.
2 Eastman and Missler, The Creator Beyond Time and Space, 80.
3 Charles Darwin, On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life (referred to simply as "Origin of Species"), Bantam Books, 1999 (reprint of 1859 original), 158.