Doctor’s Diary: The Wonder of Your Body’s Genetic Instructions
Editor’s note: Dr. Simmons is a physician and the author most recently of Are We Here to Re-Create Ourselves? He is a Fellow with Discovery Institute’s Center for Science & Culture.
As a physician and a lifelong student of biology, I have always been impressed by how the 75 trillion cells that make up the adult human body are able to follow and pass on millions of genetic instructions. These How-To, When-To, Where-To, and Combine-With “manuals,” our genes, are written in DNA code. Note that a gene is not set up for just one characteristic. Genes are lined up in a very special order within the 23 twisted, paired chromosomes found in the nucleus of each cell.
Most cells and all nuclei are far too small to be seen with the naked eye, yet they hold more information than the largest metropolitan library in the world. Possibly, more than all libraries combined. A cell can also reproduce itself entirely in a matter of hours, and over time, does so over and over again. During reproduction every gene is like a thick manual that is vertically cut in half. Only one half is given to an egg (ovum) and one sperm. A new child needs both halves. When they combine at the time of fertilization, all the varied half-instructions become complete genes (manuals) again.
New York and London
Imagine the great New York Public Library cutting every manual in half daily, sometimes more often, and sending every month entire halves to a comparable library in London that does its own cutting once a month. All of the subject matters match up, mechanics books with mechanics books, medical books with medical books, and politics with politics. Some are identical, many are not. Once connected they become a new working library with information and instructions that are constantly flying out of every window, door, and computer. Hundreds of thousands of search engines work simultaneously. Downstream, downwind, and downstairs all of life’s processes are carried out.
The sign in front of this new “building” might say UNIQUELY HUMAN LIBRARY. Other animals and plants have their own unique libraries, some with more genes/chromosomes (manuals), some with fewers. Some authors might say our blueprint resembles that belonging to a chimp, a similarity of 95 percent, but on closer inspection there are hundreds of thousands of differences. Note that a 5 percent difference in three billion nucleotide pairs means a lot of different pairs. Also, recently we have learned that 80 percent of our proteins are different from chimps’. (Stay tuned for more on this from Marcos Eberlin.) The reason may lie in different messaging. The messengers may look alike, but the coded messages do not.
A Room with a View
Think of the room you are presently in and then look at a period at the end of this sentence. That dot is larger than most human cells. Now, enlarge that period to the size of your room and place a transparent, slightly deflated basketball on the floor. You now have the equivalent size of nucleus inside a fertilized ovum. This is where each person’s library resides. It is chock full of genes (manuals), that are in fact uncountable. In some ways, select genes act like trading cards. They switch or trade places. Some jump, like an insect between blades of grass. Although a gene might reside on chromosome number 3, it might work with a gene on chromosomes number 18 and 22. The reasons for these behaviors have not been found, but it feels like outside manipulation.
Genetic “manuals” cover virtually everything needed from day one. The process does not act as if life begins later. The DNA instructions in the fertilized egg may dictate what you will look like at every second of every age, what your basic personality will be like barring tragic experiences, what your many likes and dislikes will be (what you will like to drink, what vegetable you will hate to eat, how you like your steak cooked, what characteristics you want in a spouse, etc.), how all of your organs will look and function and maybe if they might fail some day, where the billions of blood vessels and nerve cell tracts will connect, how your body will stop bleeding and/or repair wounds, the color of your skin, the color of your eyes. All this, plus much more, can be found within that “invisible” dot within a nearly invisible dot inside a pinprick.
I find all this beyond extraordinary. Living, working manuals within a living, working library cannot be the consequence of accidents of nature, trial and error, and natural selection.
As the fertilized egg travels toward the uterus, it starts dividing. With each division, it passes the genes (manuals), originally half from Mom and half from Dad, to all of its “daughter cells.” One cell readily becomes two cells, two become four, four become eight, and so on, into the millions, and, later, the trillions as an adult. Many cells change their appearance and/or activate new functions and turn others off. For example, a common ancestor marrow cell divides into pre-pre-red blood cells and pre-pre-white blood cells. Then come the pre-rbc and pre-wbc and finally the actual rbc and wbc. Later on, the wbc’s change into at least five varieties. This kind of progression is true of pre-kidney to kidney cells, pre-bone to bone cells, and so on throughout the different systems. Somehow newer cells pick and choose what directions they need to get the work done and which ones are unnecessary.
For example, the completed, thyroid hormone cells don’t need to know how to stimulate muscle fibers and the completed nerve cells don’t need to know how to use or make growth hormone. How changes like that happened, no one really knows. Although the copying process carries an incredible 99.99 percent accuracy rate, special teams stand by to make corrections in real time. Because everything is timed, all processes are actually four-dimensional.
A Biological Language
These instructions come in a biological language that is unlike anything ever spoken. It is not written in ink or typed. It cannot be read with eyes, felt with fingertips, or heard by ears. This is a biological language that can be found in all living entities. This is much too complex to have come about by serendipity. Darwinian explanations don’t apply. And, where does the spark of life come from? What or where is the soul? It’s all undetermined.
Each gene may have hundreds of directions such as construction needs, timing issues (ON and OFF), specifications, and what-ifs. For example, the gene for eye color would include where to plant each iris (the colored part), how to construct it, what are the construction materials, how to mix the different specks of color, and how to interact with each pupil in the eye. The same for hair color: where to put the thousands of hair on our bodies and possibly when to start losing some. The same for all bones; even that small groove between the nose and the upper lip, called a philtrum.
I doubt we will ever know how all of the parts work together. Certainly not what starts our engines. Only a designer could have planned all this. Common sense demands it.