Michael Cremo - Human Devolution - A Vedic Alternative To Darwin's Theory

So now we have the activated Stuart factor. But even that is not enough to start the clotting process. Before the Stuart factor can act on prothrombin, prothrombin has to be modified by having ten of its amino acid subunits changed. After these changes, prothrombin can stick to a cell wall. Only when the prothrombin is adhering to a cell wall can it be converted (by the Stuart factor) into thrombin, which initiates clotting. The sticking of the prothrombin to the cell wall near a cut helps localize the clotting action in the exact region of the cut. But activated Stuart factor protein turns prothrombin into thrombin at a very slow rate. The organism would die before enough thrombin is produced to start any effective clotting. So another protein, called accelerin, must be present to increase the speed of the Stuart factor protein’s action on prothrombin (Behe 1996, pp. 81–83).

So now the prothrombin is converted into thrombin. The thrombin cuts fibrinogen, forming fibrin, which actually forms clots. Now we can turn to the question of how to stop this clotting process once it starts. Runaway clotting would clog up the organism’s blood vessels, with life threatening results. After thrombin molecules have formed, a protein called antithrombin binds to them, thus inactivating them. But antithrombin binds only when in contact with another protein called heparin, which is found in uninjured blood vessels. So this means that the antithrombin binds to the activated thrombin molecules only when they enter undamaged blood vessels, thus inactivating them and stopping the clotting. In an injured blood vessel the clotting can continue. In this way, the clotting goes on only at the site of the wound, and not in other uninjured blood vessels. Once the injured vessel is repaired the clotting will also stop there. This is accomplished by a process just as complex as the one that stops blood from clotting in uninjured blood vessels (Behe 1996 pp.87–88).

After some time, when the wound has healed, the clot itself must be removed. A protein called plasmin cuts the fibrin network that makes up the clot. As one might guess, plasmin first exists in its unactive form, plasminogen, and must be activated at the proper time to remove the clot. Its activation, of course, involves complex interactions with other proteins (Behe 1996, p. 88).

Behe (1996, p. 86) says, “The blood-clotting system fits the definition of irreducible complexity. That is, it is a single system composed of several interacting parts that contribute to the basic function, and where the removal of any one of the parts causes the system effectively to cease functioning . . . In the absence of any one of the components, blood does not clot, and the system fails.” Evolutionists have not offered any satisfactory explanation for how this complex chemical repair system, involving many unique proteins with very specific functions, came into existence.

Blood-clotting expert Russell Doolittle simply asserts that the required proteins in the system were produced by gene duplication and gene shuffling. But gene duplication just produces a duplicate of an already existing gene. Doolittle does not specify what mutations have to take place in this duplicated gene to give the protein it produces a new function useful in some evolving blood clotting system. Gene shuffling is based on the idea that each gene is made of several subsections. Sometimes in the course of reproduction the sections of genes break apart and combine back together in a new order. The reshuffled gene would produce a different protein. But the odds against getting the right subsections of genes to come together to form a new gene that would produce a protein useful in the blood-clotting cascade are astronomically high. One protein in the system, TPA, has four parts. Let us assume an animal existed at a time when the blood clotting system was just starting to form, and there was no TPA. Let us further assume that this animal had 10,000 genes. Each gene is divided into an average of three subsections. So this means 30,000 gene pieces are available for gene shuffling. The odds of getting the four parts that make up TPA to come together randomly are thus one in 30,0004—not very likely. But the main problem is getting all the parts together into a working system. Only such a system, which contributes to the fitness of the organism, can be acted on by natural selection. Isolated parts of a system do not really contribute to fitness, and therefore there is no natural selection possible. So, in order to explain the presence of today’s human blood clotting system, evolutionists first have to show the existence of a simple blood clotting system and show step by step how changes in the genes could produce more and more effective systems that work and contribute to the fitness of an organism. That has not been done in any detailed way (Behe 1996, pp. 90–97). To escape this criticism, some scientists suggest that the parts of such a complex system could have had other functions in other systems before coming together in the system in question. But that further complicates an already complicated question. In this case, scientists would then have to show how these other systems with different functions arose in step by step fashion and how parts of these systems were co-opted for another purpose, without damaging those systems.

The Dna Replication System

When a cell divides, the DNA in the cell also has to divide and replicate itself. The DNA replication system in humans and other organisms is another system that is difficult to explain by evolutionary processes. DNA is a nucleic acid. It is composed of nucleotides. Each nucleotide is composed of two parts. The first is a carbohydrate ring (deoxyribose), and the second is a base attached to the carbohydrate ring. There are four bases: adenine (A), cytosine (C), guanine (G), and thymine (T). One base binds to each carbohydrate ring. The carbohydrate rings join to each other in a chain. At one end of the chain is a 5’OH (five prime hydroxyl) group. At the other end of the DNA chain is a 3’OH (three prime hydryoxyl) group. The sequence of base pairs in a strand of DNA is read from the 5 prime end to the 3 prime end of the strand. In cells, two strands of DNA are twisted together in a helix. The bases in the nucleotides of each strand join to each other. A always bonds with T, and G always bonds with C. The two strands are thus complementary. One of them can replicate the other. If you know the base sequence of one strand of DNA you know the base sequence of the second strand in the helix. For example, if part of the sequence of bases in one strand is TTGAC, then you know that the same part of the second strand must have the bases AACTG. So each of the two strands can serve as a template for producing the other. The end result is two new double strands of DNA, matching the parent double strand. Therefore, when a cell divides into two cells, each one winds up with a matching double strand of DNA (Behe 1998, p. 184).

For DNA to replicate, the two coiled strands of DNA have to be separated. But the two complementary strands of DNA in the parent cell are joined by a chemical bond. The replication occurs at places on the DNA strand called “origins of replication.” A protein binds to the DNA at one of these places and pushes the strands apart. Then another protein called helicase moves in, and taking advantage of the opening starts pushing down the strand (like a snowplow). But once the two DNA strands are pushed apart, they want to rejoin, or if they don’t rejoin, each single strand can become tangled as hydrogen bonding takes place between its different parts. To solve this problem, there is SSB, the singlestrand binding protein, which coats the single strand, preventing it from tangling or rebonding with the other DNA strand. Then there is another problem. As the helicase moves forward, separating the two strands of coiled DNA, the two strands of DNA in front of the advancing helicase become knotted. To remove the knots, an enzyme called gyrase cuts, untangles, and rejoins the DNA strands (Behe 1998, p. 190).