637. THE EDGE OF EVOLUTION BY MICHAEL BEHE.
Darwin's theory of evolution has three main parts: common descent, random genetic mutation and natural selection. There must be a smooth gradual rising leading to an ever more sophisticated biological system within a reasonable amount of time.
Evolution via changes in DNA is very well supported. But Behe questions whether it is random.
Behe does not reject Darwinism in toto.
Behe uses studies of malaria to examine Darwinism. A mosquito which carries malaria bites someone. It enters the blood stream and stays for a while in the liver. There is multiplies and enters the bloodstream and enters red blood cells. It eats the hemoglobin. It reproduces inside the cell and breaks out of the destroyed cell. Darwinists say that this is an arms race. The cell develops way to deal with invader and then invader reacts. On and on. The victim becomes weak and more sick and often dies. One becomes anemic. Hemoglobin carries the oxygen. The cell's solution was to change amino acid number 6. This is called the sickle cell disease. It is viewed as something awful however, this cell, sickle cell if only inherited from one parent gives the possessor safety from malaria. Malaria in this cell is detected by the spleen as defective and removed from blood stream. Someone in Africa had this mutation. Passed it on to children and that branch survived. This worked very well until enough people who inherited the single sickle cell began to marry. Then those children with complete set from both parents contract sickle cell and died. Another way developed too. Before birth we have different hemoglobin. This does not absorb oxygen from air but from mom's umbilical cord. Just before birth this hemoglobin is exchanged for normal one. This who have rebirth hemoglobin in large numbers are safe from sickle cell. This though is not evolution but deterioration. For those with sickle cell from one parent or rebirth hemoglobin are not as robust or strong just resistant to sickle cell and its dangerous effects. These genetic changes do not solve the problem and interestingly after thousands of years, sickle cell has not found a way to deal with sickle cell from one parent. Behe says that this is not an arms race but trench warfare. Other genetic weapon exist in other areas but all involve a loss of proper cell function.
How can random change fit with elegant evolution?
Humans developed chloroquine to cure malaria. Malaria eats the globin of hemoglobin. Hemo is poisonous to malaria. Chloroquine allows hem to stay, build up and kill malaria. Malaria mutated to deal with chloroquine, yet when chloroquine is not used, the malaria bacteria returns to original genetic form. This story shows that Darwins theory works but at a price. The mutated cell on both sides is not improved but debased. Darwin's theory works here because of the billions of cells involved. This increases chance for genetic mutation. Mutation is more of a factor of numbers than it is time. Yet, time is involved here too. Such numbers are absent in the case of humans.
Something which is not random must account for the common descent of life.
Out of countless possible mutations, only a very small number work. And these as seen above decrease the cells function.
Behe cites warfarin used to kill rats. Worked great until a single protein allowed rats to have resistance. But this change too reduced the efficiency of rat cells involved by 50 percent.
Uses the arctic fish as another example. None of these lead to increased sophistication.
The complexity of cellular systems like cilia challenge the concept of random mutation to explain how cells work. Studies suggest that cilia are essential for correct embryonic development. How could a slow steady pave of evolution bring together by random chance such sophistication and complexity? Gradual route randomly achieved mathematically is vitally impossible- or would require more time than the age of the universe. If Darwinism is a tinkering, then it can not be expected to produce coherent features where a number of separate parts act together for a clear purpose, involving several components. Again time is not a factor so much as numbers and rate of reproduction.
With a few minor exceptions the genetic code is the same for all the millions of species on earth. Building multi component cellular structures one protein at a time is well beyond the edge of evolution.
Behe is not the only one questioning Darwin's theory. Shapiro and a number of others are coming up with their own explanation.
James Maxwell, famous physicist, believed that there was ether in outer space and this allowed the solar light waves to travel from sun to earth. He even found math to prove his point. Later no ether was found. Ether like the blind watchmaker do not exist.
What caused nonrandom change?
pure chance
laws which predetermined outcome
environment of the earth favored certain random genetic change
intelligent design
Design is the purposeful arrangement of parts.
The molecular developmental program to build an animal must consist of many discrete steps and be profoundly coherent.
Uses fruit fly as example. An egg is laid. As it develops, one set of proteins triggers proteins to begin development of next part of the fly. Then those sections have a protein which wakes up other proteins and enzyme to do their job. Until the fly is complete. There can be no steps missed or deleted and still have a proper fly. One step relies on the next. Steady random genetic mutation does not take into account the dramatic changes required to make humans in so short amount of time.
Is Intelligent Designer the same as God? Behe says no. God is a religious concept whereas ID is a scientific grasp of Nature. But Behe interestingly goes further and fully admits that he is thinking out loud. But well worth reading.
He counts as science any conclusion that relies heavily of and exclusively on detailed physical evidence, plus standard logic. He says that ID fits the bill. He draws his conclusion from physics, astronomy and biology. Interesting how he says that astronomy backs him up. A planet's inhabitability is determined by distance from the sun, kind of sun, location in galaxy, planet can not be too big, not too small, right amount of water, right minerals in the right place, an active core. It has been suggested by astronomers that our location in the galaxy is crucial. Too near the center and we would never have come into existence due to excessive radiation. The moon was crucial too. Any one of these is probable but all together and many others raises questions about the legitimacy of pure randomness. The only way out he suggests is an infinite number of worlds. These defy reality by claiming that any scenario at any time is likely including imagining what we see. Productive thinking can not even begin. If true there is no way to trust our own ability to reason. Such arguments lack mature powers of reasoning.
Why discuss all this? Finding the edge of evolution will help medicine. Darwin says that there is a never ending battle of the arms race. ID says that we need to find the right "monkey wrench" to oppose say malaria than look upon the whole situation as an arms race.
His conclusion reminded me of Pliny the Elder- Natura Deus est. To look God in the face is to accept the beauty and the plan.
No comments:
Post a Comment