EVOLUTION INSTALLMENT TWENTY THREE

Chapter Nine (Continued)

Modularity, Evo-Devo and Control Circuitry

Remember the false red-herring argument that Darwinists attempted to use against Behe’s concept of ‘irreducible complexity’? Noting the similarities between the bacterial flagellum and the Type Three Secretory System, they claimed that the commonalities undercut Behe’s concept, when in fact the argument wasn’t relevant to the main point. But the similarities themselves led some modern neo-Darwinists to attempt to capitalize on them in another way. The Modularists claim that the similarities between a number of biological subsystems in entirely different functional settings shows how evolution has taken advantage of opportunities for natural selection to considerably shorten the evolutionary path by borrowing large modules from other subsystems and, with minor modifications, utilize them for their own purposes. This concept of modularity supports and attempts to revive with the more advanced knowledge base of modern molecular biology the earlier notion of ‘punctuated evolution’ proposed by the late Stephen J. Gould.

What the Modularists have actually accomplished is to undercut the central feature of the Darwinian mechanism: modification through a huge number of tiny, incremental steps. With the arrival of the concept of modularity, many evolutionists have come out of the closet to acknowledge that Darwin’s original mechanism was unworkable. They were more than happy to do so, because in finding this new mechanism they were able to admit the obvious problems with the ‘old’ evolution while keeping God at bay with another purely naturalistic process. But does this new replacement mechanism actually offer a better evolutionary process?

There are at least three reasons why the concept of modularity doesn’t offer the breakthrough that evolutionists thought it did. First, it doesn’t explain how the modular component came into existence in the first place. Like the shopworn theory of panspermia, all it does is push the problem back a little. Second, the ‘modular’ components aren’t entirely modular. What works in one system context requires considerable modification to fit into a different system having different functional objectives. The Type III Secretory System and the bacterial flagellum offer an excellent example of this. Conversion from one function to another requires plenty of modification. Where is the intellect in evolution to see the commonality of these devices in the face of their differences? Third, each of these ‘modular’ systems doesn’t exist in isolation. They must be integrated into a higher-level control structure to be useful in any system. The integration process is, itself, a major system modification. This third complicating factor is addressed below.

Recent advances in the field of molecular biology have uncovered another fascinating and extremely complex biological process: a hierarchy of switching modules that operate to sequentially control the development of embryonic life and, once developed, support its maintenance7. The switching proteins act on portions of DNA to coordinate like a symphony conductor their activation and inhibition to produce and maintain the end product, a viable creature. In actuality, the control mechanisms operate together to form a finite-state machine of gigantic complexity.

One very simple example of sequential control is that of hemoglobin, which transports oxygen from the lungs to cells throughout the body. This delicately-tuned mechanism must bind oxygen with sufficient strength to pick it up from the lungs, but still retain the capability of releasing it where it is required. Prior to birth, however, the embryo acquires its oxygen from its mother’s placenta rather than its lungs. That mechanical difference requires an embryo’s hemoglobin to differ from the post-birth form. It is one job of the body’s regulatory mechanism to perform the switching from one form of hemoglobin to the other at the appropriate time8.

Finite-state machines and their characterization have occupied the minds of many scientific thinkers and engineers for well over a generation, resulting in the twin disciplines of computer hardware and software, the end products of which are considerably less complex than their biological counterparts. Merely the characterization of the switching systems relevant to computers, both hardware and software, requires schematics supported by state diagrams and other conceptual tools. Scientists have just begun to schematically characterize some simple biological control systems9; one product of their work closely resembles a system schematic diagram.

The insight into biological control systems has led to the formation of another group of neo-Darwinists who apply the notions of modularity and control systems to embryology. These specialists in ‘evolutionary developmental biology’, or ‘evo-devo’ for short, look for mutations and selection during the developmental phase of life as a viable evolutionary pathway.

But Behe notes that in his study of the evolutionary histories of viruses, bacteria and humans he encountered no evidence whatsoever of modular evolution. To answer the question posed earlier, there is a big reason why this is so: rather than supporting evolution, both modularity and control circuitry work against it. Modular structures still require the initial evolutionary development to create the first instance of them; furthermore, the integration of an existing module into a new system to serve a different purpose demands not only the complex alterations necessary to fit into the new purpose, but, more importantly, the even more complex alterations necessary to adapt the existing control mechanism to properly sequence the initiation of the structure into the larger system. The latter problem is a huge one and is essentially overlooked by the Modularists and evo-devo researchers. The control issue raises another companion issue that also is frequently overlooked by evolutionists, that of the added level of complexity associated with the necessity for complex biological machines not only to operate, but to self-assemble. In finding that getting just two proteins to work together to do something useful was beyond the boundary of evolution, Behe also notes that he simply addressed the basic system without the added complexities of self-assembly, associated control circuitry and modular integration.

Coordination

The added complexity as noted above of developing and integrating the control structure for an improvement, along with the improvement itself, into a higher-level structure is but one facet of a very broad category of evolutionary difficulties, that of coordination. Evolution works on single-point changes with absolutely no consideration of the systems integration aspect of such modifications; yet, life exhibits coordination everywhere. Symbiosis among self-contained but mutually-supporting systems stretches the improbability of the combined systems far beyond what it would be if the systems were independent of each other.

Take DNA, for example, which as a software code is useless without the supporting hardware. Specifically, the DNA code for protein synthesis (genes10) is meaningless without the supporting systems of messenger RNA, transfer RNA and ribosomes that utilize the DNA code in assembling proteins out of amino acids. But the constituents of ribosomes are proteins, which means that proteins cannot exist without the prior existence of proteins – DNA and certain proteins had to exist together in a coordinated manner. This poses a huge problem for evolution.

Then there’s the symbiosis implicit in sexuality. In the previous chapter we recounted the multi-level nature of the irreducibly complex systems that go into the characterization of living creatures. We briefly addressed various rungs of the ladder, from DNA and other sub-cellular systems, up through the cell, to the higher-level functions such as the heart and brain, ending up with the complete self-contained human being. Had we wished to, we also could have delved below the molecular level to the anthropic nature of chemistry itself, with the amazing properties of the hydrogen, oxygen and carbon atoms; without these properties, life would be impossible. But we also could have expanded on the other end, for the individual human being is anything but self-contained. Male and female are complementary functional subsystems of a greater human entity called family. Like DNA and ribosome, they are interdependent; one cannot exist without the other. Most critically, they must unite to provide continuity of the human race. Much of the biological equipment of both males and females, including but not limited to the sexual, gestative and mammary subsystems, and even the subtle differences in emotion and cognition, exists to support the function of propagation. The evolutionist might attempt to counter this argument regarding sexual interdependency by pointing to the human as an example of gradual improvement of a living creature that began at the level of a simple cell. But since sexuality and the necessity it places on interdependence extends all the way down to the level of the cell, that argument would buy exactly nothing.

Even the human family unit with male, female and children is not sufficient in itself. In addition to the food we require for survival, we breathe air to obtain oxygen, of which there is a finite amount in our world. Fortunately, plants thrive on the carbon dioxide that we expel, restoring oxygen to the atmosphere. Granted, plants and animals can change rather independently of each other without upsetting the symbiotic applecart, but their mutual dependency raises the question – and it is a big one – of how these two very different forms of life came to coexist in such a perfectly complementary fashion.

Observe how the eye, as another example, is so tightly coordinated with the activity of the brain. Without the brain to process the information that the eye supplies to it, the eye itself would be completely useless. The same can be said for the numerous other subsystems in addition to vision that supply information to the brain11: hearing, taste, touch and comfort and pain sensors. Beyond the necessity for the brain, the eye requires several subsystems of its own simply to function properly: the musculature that moves the eye; the lacrimal system with its several components including specialized chemicals that protect and maintain the cleanliness of the eye and help to supply it with oxygen; the specialized, transparent construction of the cornea; the variable lens and its associated muscles and control mechanisms to maintain focus; the iris and its associated muscles and control mechanisms to admit the proper amount of light; the retina and the multi-step sequence of chemical changes for converting the impact of photons to nerve impulses; the system of veins that delivers oxygen and vital molecules to the eye; and the extensive system of nerves by which the eye communicates with the brain.

In summary, a host of symbiotic systems are found in ‘nature’, which are so mutually dependent that to have evolved, they had to evolve in lockstep with each other. At the molecular level, virtually all biological processes exhibit some form of mutual interdependence. Examples of symbiotic coordination abound in biological systems at the macro level: sensor/nerve/brain; brain/nerve/muscle; heart/lung/circulatory; muscle/bone/ligament. Examples of symbiosis at the level of complete creatures include the role of bees and birds in pollinating plants; the small fish who operate cleaning stations for larger fish, acquiring meals in the process;

While the evolutionary development of symbiosis among lifeforms is logically tenable, this feature requires the simultaneous complementary development of symbiotic partners. Therefore, symbiotic coordination vastly increases the odds against that occurrence over the already astronomical odds associated with their individual development.

Coordination has implications other than symbiosis and mutual dependency. It also demands that a change in one subsystem must be complementary to all the others upon which it may have some impact. Evolution takes a big hit from this issue, as the already miniscule probability of large functional changes is rendered even lower by the necessity for complementary changes initiated by a first change.

This integrated-systems aspect of life for both man and animals begs for anticipation. The numbers associated with the chance development of any one of the multitude of associated subsystems are so tiny as to preclude possibility; the numbers associated with their coming together in such integrated fashion are enormously smaller.

Many of these subsystems are specific to us as humans, and cannot readily be integrated into other animals. The same may be said about the other animals. Wings, for example, are specific to birds. They support flight. The keen eyesight of the raptor is a necessary subsystem also needed to support the ability of flight, as are the balance mechanisms and nervous systems, the hollow skeletal structure and the heart and lungs, all of which necessarily differ from their associated functions in humans. Now, suppose, in a primitive society living on the edge of existence, that a man were suddenly to develop wings. Suppose also that by some amazing oddity of chance, that the wings were fully developed, but that his nervous system, remaining unchanged, was fully and exclusively human. The man wouldn’t be able to fly, because the signals to cause them to flap wouldn’t exist in the perfection that they are found in birds. Or, alternatively, suppose that the man’s bones still contained marrow, and remained solid and heavy as they always have. He wouldn’t be able to fly in that condition either. Or yet again, suppose that his gut and food-processing organs remained fully human. He might be able to fly, but he wouldn’t be able to stomach the standard dining fare available to raptors.

Under the presuppositions made above, would the wonderful wings that this man was lucky enough to be endowed with represent a boost to his chances of survival? Most definitely not. They’d represent useless appendages that would do nothing but weigh him down and make him more awkward. He’d be poor competition to his fellows, who’d have a big edge over him for survival. The poor man would be nothing but a useless monstrosity, and this dubious gift of wings would cause him to die out. End of wings.

This notion of coordination among modifications can be generalized out of the example noted above, which is but one of a very large number of examples in which evolution has claimed the ability to accomplish a sweeping functional change: that of a land animal that walks with the aid of legs who is eventually going to achieve the ability to fly. To accomplish this, its bones need to become hollow and highly efficient with respect to weight; it has to develop the keen eyesight unique to birds that is appropriate to its mode of hunting from the air; its bone structure, particularly in its chest, needs to be arranged to be a proper scaffold for its ligaments and muscles; its arms need to assume the shape of airfoils; it needs the lightness, shape, and variability of shape of feathers for fine control over flight; its respiratory system must become suitable for the demands of flight, which involve hefty changes from the comparable functions of a land animal; its balance mechanism must be revamped to handle flight attitudes; its entire nervous system must be altered to furnish the ability to control its airfoil surfaces; and, perhaps not least, it must acquire some pretty disgusting eating habits. Each of these functional modifications involves very large numbers of changes that have to be made in the proper sequence. This requirement for a large number of sequentially-supportive steps, all mutually compatible over a variety of different subordinate functions to the end of achieving flight, virtually demands the quality of anticipation or goal-setting which is the hallmark of a designer. As if that isn’t contradictory enough of evolution, consider the implication of the large time scale evoked by most evolutionists to accomplish these changes. During the long time frame over which these changes are accomplished, there will be of necessity several periods in which the poor beast will be struggling with intermediate forms, such as arms that are developing into wings. In this transitory stage, the creature must continue to survive its environment, eat and mate. It must do so while suffering the disadvantage of limb that functions less well as an arm than it used to, and is not yet functional as a wing. At this stage, it is suited far more as a food source for some other less-advanced animal. At the other extreme, some supporters of evolution who have come to understand such implications of large functional changes have proposed that such changes must have occurred quite suddenly. The ‘punk-eek’ crowd12 that favors this cutesy expression of ‘punctuated equilibrium’ first proposed by evolutionist Stephen J. Gould are fond of avoiding the consequences of prolonged transition periods. Their problem is that in the process of forming their opinions, they also have avoided doing the math: the odds against all these coordinated modifications occurring all at once are so astronomically minute that the numbers against even one instance of such an event having taken place are so vast that they outweigh by a huge margin all the time available even by the most far-fetched uniformitarian assumptions of the age of the universe. In another light, the numbers are greater by a huge ratio than all the particles in the universe13.

The features and function of the DNA molecule express rather loudly the notion of anticipation, the purposeful creation of exquisitely complex order out of chaos. Its very existence inspires the awe of someone monitoring a SETI screen, like Jodie Foster in the movie “Contact”, and suddenly viewing an intelligent signal from outer space.

[to be continued]

NOTES:

7. Ibid., Chapter 9

8. Ibid., p. 27

9. Behe, The Edge of Evolution, Figure 9.3, p. 196

10. Meyer, Signature in the Cell, pp. 461-480; also Google on “gene”, “intron”, “exon”

11. note 8, Chapter 8

12. Phillip Johnson, Darwin on Trial, pp. 50-61

13. William Dembski, Intelligent Design, pp. 166, 266

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