DNA: Our Genetic Lifeline
When I chose the title From God to DNA for this book, I was not trying to be facetious or stimulate sales. The title reflects a real transition in my life. To my knowledge, the DNA is the only thing that can create life. And since it moves from one generation to the next in an unbroken line, it is the only thing I know that approaches immortality and sweeps a small bit of each of us into the future. Do I remember Jesus saying that the Kingdom of God is within you?
When I was very young, I was taught that God was all loving, all knowing and all powerful. I was taught that he answered prayers and interceded in the lives of his children. But I don’t see any evidence of this. We are familiar with all too many atrocities like war, famine and disease that beg the question: “Why doesn’t God intervene? Where is this loving, caring Father?”
We were told that God was the ultimate answer to the most pressing human questions. But it seems to be an answer endlessly delayed. During my studies I have slowly seen God evaporate before my eyes. I find nothing behind the word God that is worth putting my faith and trust in anymore. Gods are the graveyards of hope.
By contrast, I have found something that truly is answering questions for me. These are the same questions that I used to ask of God and got no answers. During the last half century, the scientific world has opened up explanations about the workings of the human genome, especially the brain, that I find amazing. I have followed this scientific effort as best I can as an amateur and find myself fascinated beyond measure. What I like most is the promise of the DNA to understand and help cure people with illnesses that religion can’t touch.
I recognize that many people are not familiar with the advances of modern neuroscience and cannot appreciate the contrast I am making here. I strongly urge you to start reading. It is truly the leading edge of science and self-understanding.
Now that we have moved from the section on God to the section on DNA, I owe it to the reader to explain the title in more detail. For this, I am going to back up a few billion years and witness the beginning of life itself.
The most common elements on the planet in the pre-historic era were carbon, hydrogen, oxygen and nitrogen, collective known by the acronym CHON. These elements were not unique to Earth, but were the result of exploding stars that spread throughout the Universe.
Combinations of these elements are known to make amino acids, the building blocks of all life. Dr. Harold Urey, Nobel Laureate, and a graduate student demonstrated in the laboratory how amino acids could be made quite easily. They put the four CHON gases into a flask, discharged an electrical spark through them, and discovered that they had produced an amino acid. This was a major scientific finding.
Obviously, if this could be done in a lab, it could be done naturally by lightening strikes on a much larger scale. And more lightening strikes with different concentrations of the same four CHON gases could produce different amino acids. We now know that only four different small amino acids are used in making DNA. They are called adenine (A), thymine (T), cytosine (C) and guanine (G).
What is fascinating to me is how these small amino acids couple together. When two amino acids join, they do not necessarily stay in a flat plane. Each of them has positive or negative charges that attract of repel adjacent parts, causing them to fold. When a third amino acid joins the first two, there is more folding. This process continues until they form structures that are very modernistic. The smallest gene contains about 300 co-joined amino acids and looks like a bowl of spaghetti.
The important concept here is that the shape determines its function. If any one of the basic acids, A, T, C, or G, is accidently substituted for another in transcription at any location in the “chain”, it will result in an entirely different shape, hence function. By function, I mean what it does in the body, like being a muscle cell, a liver cell, etc. These complex shapes form receptor sites such that specific chemicals can communicate with them.
Progressively these small amino acids coupled together to make more complex molecules that would eventually grow to become our enormous DNA.
From early on, these molecules exhibited behaviors that implied they had a mission and a strategy for achieving it. The mission has three parts that have never changed. They (1) adapt to the environment, (2) survive and (3) reproduce. In a curious way, this evolving molecule seems to be creative. But I know that it is just adjusting to the environment in a way that allows it to survive. Think of these remarkable adaptations.
Certain advantageous mutations allowed it to extract energy from the environment by a process we call photosynthesis. It evolved a respiratory system that allowed it to survive in the presence of toxic oxygen. It evolved systems of metabolism to process food and extract its nutrients. All the while it was getting bigger and forming new species by mutations.
I don’t know when the intangible qualities entered in this progressive growth. We certainly know that we possess thinking, feelings and morals. We see smaller animals that also possess at least some of these qualities. And we can reasonably assume that they did not appear fully developed like fireworks on the Fourth of July. For example, it is known that before these evolving life forms evolved pigmentation, members of their colony would crawl on top of others and sacrifice themselves to protect the colony from harmful radiation, all in the name of survival. Was there thinking or morality there?
They evolved appendences in the forms of fins, wings and legs to obtain locomotion. They evolved all the senses to let them communicate with the outside world for survival. The list goes on and on to include every feature and function of every species. But most impressive of all, for me, is the evolution of the human brain.
There is evidence that the human brain evolved in three stages. The earliest part was called the reptilian brain. It is found in very early life forms and has been retained by us through evolution. It controls most of the automatic functions of the body. The second part of the brain to develop was the limbic system that controls most of the emotions of the body. It is the first part of the brain to receive sensory information and to take action on it quickly for our protection. The third part to develop was the neo-cortex that is used for executive functions, judgments, analysis, etc. The limbic system is faster than the neo-cortex and often over-rides judgment in taking actions. The rule of counting to ten before taking any action makes neurological sense.
And all this “growth” was done by billions and billions of beneficial mutations. Of course, there were billions and billions of non-beneficial mutations that caused some species to be less adaptive to the environment and eventually reproduce less and die off. Mutations are amoral. If they aid the species, all is well and good. If they don’t, it’s the cruel price of progress. Like all natural laws, they are impartial.
This process would not be thinkable without the billions of years that the process has been going on. But now we know that the mechanism of natural selection that enables evolution is the mutation of genes. And the collective result of all advantageous mutations is the molecule of life known as DNA.
I find this incredible. It boggles my mind to learn that something that has been shrouded in mystery is finally revealing itself through patient research.