May
4
Do You Wanna Build a Cell, Man?
I re-read Michael Denton’s Evolution: A Theory in Crisis (1986) recently. When he wrote the book, Denton, an agnostic, was an Australian medical doctor and scientist doing biological research in Sydney. It was one of my favorite books when I was reading a lot on the evolution/creation/ID “debate” back in the 2000s, and I wanted to refresh my memory on Denton’s material before I (finally) read his follow-up, Evolution: Still a Theory in Crisis (2016).
There were many sections that I thought of citing in a post, and I still may, but I thought this particular citation would be a fun one. It comes from the penultimate chapter, titled “The Puzzle of Perfection”….
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Perhaps in no other area of modern biology is the challenge posed by the extreme complexity and ingenuity of biological adaptations more apparent than in the fascinating new molecular world of the cell. Viewed down a light microscope at a magnification of some several hundred times, such as would have been possible in Darwin’s time, a living cell is a relatively disappointing spectacle appearing only as an ever-changing and apparently disordered pattern of blobs and particles which, under the influence of unseen turbulent forces, are continually tossed haphazardly in all directions.
To grasp the reality of life as it has been revealed by molecular biology, we must magnify a cell a thousand million times until it is twenty kilometres in diameter and resembles a giant airship large enough to cover a great city like London or New York. What we would then see would be an object of unparalleled complexity and adaptive design. On the surface of the cell we would see millions of openings, like the port holes of a vast space ship, opening and closing to allow a continual stream of materials to flow in and out. If we were to enter one of these openings we would find ourselves in a world of supreme technology and bewildering complexity. We would see endless highly organized corridors and conduits branching in every direction away from the perimeter of the cell, some leading to the central memory bank in the nucleus and others to assembly plants and processing units. The nucleus itself would be a vast spherical chamber more than a kilometre in diameter, resembling a geodesic dome inside of which we would see, all neatly stacked together in ordered arrays, the miles of coiled chains of the DNA molecules. A huge range of products and raw materials would shuttle along all the manifold conduits in a highly ordered fashion to and from all the various assembly plants in the outer regions of the cell.
We would wonder at the level of control implicit in the movement of so many objects down so many seemingly endless conduits, all in perfect unison. We would see all around us, in every direction we looked, all sorts of robot-like machines. We would notice that the simplest of the functional components of the cell, the protein molecules, were astonishingly complex pieces of molecular machinery, each one consisting of about three thousand atoms arranged in highly organized 3-D spatial conformation. We would wonder even more as we watched the strangely purposeful activities of these weird molecular machines, particularly when we realized that, despite all our accumulated knowledge of physics and chemistry, the task of designing one such molecular machine — that is, one single functional protein molecule — would be completely beyond our capacity at present and will probably not be achieved until at least the beginning of the next century. Yet the life of the cell depends on the integrated activities of thousands, certainly tens, and probably hundreds of thousands of different protein molecules.
We would see that nearly every feature of our own advanced machines had its analogue in the cell: artificial languages and their decoding systems, memory banks for information storage and retrieval, elegant control systems regulating the automated assembly of parts and components, error
fail-safe and proof-reading devices utilized for quality control, assembly processes involving the principle of prefabrication and modular construction. In fact, so deep would be the feeling of deja-vu, so persuasive the analogy, that much of the terminology we would use to describe this fascinating molecular reality would be borrowed from the world of late twentieth-century technology.
What we would be witnessing would be an object resembling an immense automated factory, a factory larger than a city and carrying out almost as many unique functions as all the manufacturing activities of man on earth. However, it would be a factory which would have one capacity not equalled in any of our own most advanced machines, for it would be capable of replicating its entire structure within a matter of a few hours. To witness such an act at a magnification of one thousand million times would be an awe-inspiring spectacle.
To gain a more objective grasp of the level of complexity the cell represents, consider the problem of constructing an atomic model. Altogether a typical cell contains about ten million million atoms. Suppose we choose to build an exact replica to scale one thousand million times that of the cell so that each atom of the model would be the size of a tennis ball. Constructing such a model at the rate of one atom per minute, it would take fifty million years to finish, and the object we would end up with would be the giant factory, described above, some twenty kilometres in diameter, with a volume thousands of times that of the Great Pyramid.
Copying nature, we could speed up the construction of the model by using small molecules such as amino acids and nucleotides rather than individual atoms. Since individual amino acids and nucleotides are made up of between ten and twenty atoms each, this would enable us to finish the project in less than five million years. We could also speed up the project by mass producing those components in the cell which are present in many copies. Perhaps three-quarters of the cell’s mass can be accounted for by such components. But even if we could produce these very quickly we would still be faced with manufacturing a quarter of the cell’s mass which consists largely of components which only occur once or twice and which would have to be constructed, therefore, on an individual basis. The complexity of the cell, like that of any complex machine, cannot be reduced to any sort of simple pattern, nor can its manufacture be reduced to a simple set of algorithms or programmes. Working continually day and night it would still be difficult to finish the model in the space of one million years….
Undoubtedly, the complexity of biological systems in terms of the sheer number of unique components is very impressive; and it raises the obvious question: could any sort of purely random process ever have assembled such systems in the time available? As all the complexity of a living system is reducible ultimately to its genetic blueprint, the really crucial question to ask is what is the sum total of all the unique adaptive genetic traits necessary for the specification of a higher organism like a mammal?
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That was forty years ago! A lot more has been discovered about the intricate complexities of the cell’s systems since then, and it only gets more challenging for neo-Darwinists to insist — against all odds — on purely natural mechanisms being responsible for life and its diversity on the Earth.
P.S. For more in-depth discussions on these and related issues, I highly recommend The Cell’s Design (2008) and Creating Life in the Lab (2011), both by Fuz Rana.
