Before looking at the second major line of evidence for the existence of God, we need to have a basic understanding of how life works. Deoxyribonucleic acid, or DNA for short, is a molecule that contains the blueprint for life on Earth. It has a unique shape called a double helix, that looks like a ladder or staircase twisted round on itself. This is known as the “primary structure” of DNA.
Information is stored in DNA using four units, called “bases.” Those bases are adenine, cytosine, guanine and thymine, often abbreviated simply to the letters A, C, G and T. They occur in pairs – A with T, and G with C – to create the rungs of the DNA ladder. This structure, known as the “secondary structure” of DNA, makes it very stable. Each side of the ladder acts as a backup for the other, so that information can be preserved efficiently.
Human DNA is about 3 billion base pairs in length. With the exception of blood cells, almost every cell in your body contains a copy of your DNA sequence, which is stored in the nucleus of the cell. Human DNA contains about 20,000 “genes,” a somewhat loose term often used to describe sections of DNA that contain instructions for building a “protein.” In turn, proteins are three-dimensional structures that make up the machinery of our bodies.
How is a protein made? Imagine a library filled with books, and each book contains instructions for how to build a particular protein. For some reason, you aren’t allowed to take any of the books out of the library. If you want to make a specific protein, you would need to find the relevant book, make a copy of it while in the library, and then take the copy outside. Waiting outside is a protein making machine. You could feed your copy of the book into the machine, which would then read the instructions and build the protein for you.
This is a simplified analogy for what happens in the cell. The library represents the DNA blueprint, and the books are the genes it contains. The main difference is, the DNA molecule is like one enormous book containing all the genes and more.
Before a protein can be made, two main processes have to take place. The first is similar to the copying process in our analogy. Biologists call it “transcription.” The sequence of DNA that contains instructions to build a particular protein is copied to “messenger RNA,” or “mRNA” for short. DNA and RNA are similar, but while DNA has a double strand, RNA has only a single strand, and the thymine (T) base in DNA is switched to uracil (U) in RNA, a different base.
Some parts of the newly created RNA strand don’t code for the protein, so they are cut out. This is called “RNA splicing.” By arranging the remaining pieces of the RNA into different patterns, different proteins can be made in the second major biological process, which I will describe next, called “translation.”
A molecular machine called a “ribosome” is needed to make a protein, along with “transfer RNA” (or “tRNA”) molecules, which bring along the amino acids that will form the protein. The ribosome attaches itself to the mRNA strand, and reads the RNA code 3 bases at a time. A set of 3 bases is called a “codon,” and each codon normally represents one amino acid, which are the building blocks of proteins.
The ribosome has three binding sites in it. As it moves along the mRNA strand, tRNA brings along an amino acid that matches up with the codon being read by the ribosome at the time, and the tRNA molecule moves into the first site. It then moves to the second site, and the amino acid it carries is attached to a growing chain of amino acids. The tRNA then leaves the ribosome from the third site.
There are also codons that tell the ribosome to stop making the protein. When the ribosome encounters a stop codon, the chain of amino acids is released. This chain is the protein itself, which then usually folds into a shape that is useful for the body.
These two processes – “transcription” or copying of DNA into messenger RNA, and then “translation” of mRNA into proteins – are so important, they are a major part of what is often called the “Central Dogma” of biology.
The reason I have explained them in some detail here, is because I will now present evidence that the structure of DNA, the pairing of the four DNA bases, “transcription” into mRNA, “translation” of mRNA into proteins by a ribosome, and even the modern names of two of the bases used in DNA and RNA, have been hiding in plain sight, in a simple account about the life of a shepherd named Jacob, written thousands of years ago.
LetterToTheAtheists.com | Contents | Previous Chapter | Next Chapter >>>