Computers are fascinating machines. They can calculate, store vast amounts of information, and even keep track of the various devices that are plugged into them. The Central Processing Unit, or CPU, of some modern computers can send or receive instructions at the rate of 2 billion times a second.

   As amazing as some of their actions are, the language that computers speak is very simple. All the instructions that computers send and receive are in a series of on or off electrical impulses. Either the impulse is on, or it is off. Either there is electricity on the line, or there is not. These on or off impulses are what are known in the computer business as binary code.

   Keep reading, it gets more interesting.
   Although the computer reads on or off electrical impulses, binary code is how people program computers. People must translate our instructions into computer language, and they use binary code to do it. In binary code, computer programmers indicate an on or off impulse by either a 1 or a 0. Each 1 or 0 is called a bit. These 1's and 0's (bits) are arranged in sets of eight, called bytes. Each byte represents a letter, character, or a number. Whether that byte is a letter, a number, or some other character depends on how the 1's and 0's are arranged. For instance, the letter A is represented as 01000001 while the number 25 is represented as 00011001. Rearranging the order of the byte makes a completely different number or character. So inside the computer, all the instructions that cycle through the CPU can be thought of as just a bunch of 1's and 0's.

   Now hang in there, it does get better.
   The operating system is a set of instructions that lets people run the computer. The operating system acts as a go-between between people and the physical parts of the computer. Without an operating system, the computer is just a big paper-weight.

   Early operating systems were simple affairs. Over the years, teams of skilled programmers and engineers have developed much more complex operating systems. One of the most popular operating systems today consists of 650 million bytes of data. Remember a byte is a set of eight 1's or 0's. That means there are 5.2 billion 1's or 0's in this operating system. Each 1 or 0 has to be in the correct sequence. If they are not, the operating system may not work as it is supposed to, or it may not work at all, and your computer will be just a hunk of junk. To be completely accurate, we must point out that these 5.2 billion bits are compartmentalized into files and programs, to reduce the likelihood of error.

   If you try to tell a computer programmer that he can improve a computer program like an operating system, by randomly changing say, 300 possible combinations of 1's and 0's he would laugh in your face. It takes months of effort by a team of engineers to make an improvement to an operating system. It doesn't matter how many times you randomly change the 1's and 0's in a program's binary code. Random changes will only result in turning a computer into a big paper-weight.

   As amazing as computers are, human life is infinitely more complex. This, of course, brings us to a brief discussion of deoxyribonucleic acid, also known as DNA. DNA is the building block of proteins, of which we are all comprised. The nucleus of every cell in the human body contains DNA. The structure of the DNA molecule determines whether its owner is a bean-plant, a long-eared mule, or a human being.

   The DNA molecule is long, thin, and is shaped like a ladder that has been twisted into a spiral. It could also be described as a twisted chain. Each rung of the ladder consists of two bases (a base is the opposite of an acid). One base is attached to one side of the ladder, and its mate is attached to the opposite side of the ladder. So each rung of the long DNA molecule is made of two bases joined in the middle. These bases, which comprise the rungs of the ladder of the DNA molecule, are always one of four specific kinds. The four bases are adenine, guanine, thymine, and cytosine. The bases always pair off with each other in this manner: adenine pairs with thymine, cytosine pairs with guanine. Each individual base combined with that portion of ladder that it is attached to, is called a nucleotide.

   Now remember this part. Each side of the DNA ladder may have any of the four bases attached to it. It is the order of these bases on the side of the DNA molecule that determines if it belongs to a bean-plant, a long-eared mule, or a human being. In human DNA, there are some three billion pairs of bases, or rungs on the ladder, in the DNA molecule. Each pair of these bases has to be in the correct position, and in the correct order.

   Don't quit yet, we're almost there.
   When cells are about to divide, the DNA molecule splits apart. The DNA molecule splits directly in half, long-ways down the middle. The pairs of bases, or rungs are split. Free floating bases and other chemicals link up to the half ladder in the combinations indicated above, and bit by bit, the two halves rebuild themselves into two new molecules, each an exact replica of the original.

   That is how it is supposed to work. When the DNA molecules split apart sometimes the wrong bases get attached in the wrong position. The change in the position of one base can lead to a genetic mutation.

   The change or addition of just 300 of these three billion pairs of bases in the human DNA molecule can lead to an entirely different protein. That would drastically alter a person's genetic makeup. Mutation city.

   Time to remember your math. There are four bases that could be attached to any part of the DNA ladder. Changing 300 of the bases would lead to four to the three-hundredth power, or 4300, possible combinations. That would be 4,149,515,568,880,990,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,
000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000. possible combinations!

   What are the chances that out of all these possible permutations, the one right combination will fall into place? What are the chances that an improvement in the genetic code will occur? In a computer program, randomly changing the combinations of 1's and 0's will result in an error. The exact same is true for our DNA, which is, if you will, the program that makes human beings operate. Whether it is done slowly bit by bit, or all at once, you can see how many possible combinations can be obtained by changing even a few of the links in the chain that make up human life.

   These changes are not done randomly. Just as a computer's code must be designed and modified by a creator, so our human code was created by the intelligent design of our Heavenly Father.

   Never let anyone tell you that computer programs are made by randomly throwing in handfuls of 1's and 0's. Neither can they tell us the perfect order of the three billion pairs on our DNA was the product of some random process. If the process was random, we could all be long-eared mules.



Published by The Minnesota St. Thomas More Chapter of Catholics United for the Faith, March 2003.