This question reminds me of an old joke about the agnostic, dyslexic, insomniac who stayed awake all night trying to decide if there really is a dog.
For those who want to believe there is no God (atheists), one question they have to wrestle with is, “Where did life come from?” Charles Darwin tried to give a partial explanation with his theory of evolution. He tried to show how accidental mutations of existing species of organisms coupled with the law of the survival of the fittest could lead to the development of new species from existing ones. When he expounded his theory he said that as more and more fossils were discovered we would be able to find fossils of transitional forms as one species was gradually changed to another. Unfortunately, after more than 140 years of searching, the fossil record still does not bear that out.
The fossil record shows not only just distinct species without transitional forms, it also tends to show those species suddenly appearing. A good example of that is sometimes referred to as the “Cambrian Explosion”. Here is what Wikipedia has on that, “The Cambrian explosion or Cambrian radiation[1] was an event approximately 541 million years ago in the Cambrian period when practically all major animal phyla started appearing in the fossil record.[2][3] It lasted for about 13[4][5][6] – 25[7][8] million years and resulted in the divergence of most modern metazoan phyla.[9] The event was accompanied by major diversification of other organisms.” That description sounds to me more like the language repeated several times in the first chapter of Genesis, “And God said, … and there was…”
There have been many attempts to develop a theory to explain the origins of the first life on earth having been the result of random or accidental events. Those theories all revolve on accidentally producing the first self-replicating molecule, and then Darwin’s theory of evolution kicks in and it eventually evolves into higher and higher levels of existence.
When those theorists say “self-replicating molecule”, they want us to think “DNA”, and some will then point to what seems to be the simplest form of life, the virus, that is little more than some DNA with a protective membrane around it. By one definition, a virus is not even a life form since it cannot reproduce itself. It can only be reproduced by infecting a healthy cell and hijacking that cell’s reproductive mechanisms forcing the cell to reproduce the virus. If you subscribe to the thought that life progressed from the simplest to the more and more complex then the first form of life had to be a complete, fully functioning single-celled organism.
Also, there is no such thing as a self-replicating molecule. DNA is replicated by the action of at least three other molecules that are created and controlled within a complete cell. Cells are most often reproduced by cell division. When it is time for a cell to divide, all of the DNA must be duplicated so that each new cell will have a complete set. I will try to describe that process using non-technical terms to describe the molecules that perform the various steps required.
Each DNA molecule or chromosome is often compared to a ladder that has been twisted along its length. The first step in duplicating it is to cut that strand into two pieces along its length. That process is performed by a molecule I call the cutter molecule. It travels along the length of each chromosome cutting it apart in the middle of each rung along the ladder. The result is two separate half chromosomes that are twisted around each other since the original chromosome was twisted.
The next step in the process is performed by a molecule I call the untangler. The way the action of this molecule was explained to me is that this molecule goes down the two half strands of DNA and about once for each revolution of the twist it disconnects one half strand, passes one end of it around the other half strand of DNA and then re-connects the broken strand effectively untangling the two half strands.
The third step in the duplication process uses a molecule I call the rebuilder. This molecule travels down each half strand of DNA and rebuilds the missing half from the information in the exiting half. When all three steps have been performed on all chromosomes in the cell then the cell is ready to divide into two complete, fully functioning new cells.
For this duplication process to work properly there must also be very strict controls on it. The processes of each of the three molecules can only be allowed to happen once to each chromosome and be prevented from happening again until after cell division has occurred, each new cell has absorbed enough nutrients from its environment, and the new cells have grown large enough to support the cell dividing again. I will address more on these controls later.
I don’t know how many of these three duplication molecules are required for any given cell to be able to divide. I know it takes at least one of each but it may be more than that. Whatever that magic number is, after a cell has divided into two new cells one or both of the new cells will be short of that number and will need to be able to create new ones before cell division can take place again.
DNA is information encoded by the sequence of molecules that make it up. It is a set of instructions on how to assemble the complete organism of which the cell is a part. That includes the instructions on how to assemble all molecules that cell needs to function properly. That process of reading the DNA and assembling needed molecules is carried out by another pair of molecules.
The first of these two I call a reader molecule. Somehow the reader molecule is told what new molecule is required, finds the correct chromosome and the location on that chromosome with the proper instructions, and makes a copy of that section of DNA forming a new molecule called messenger RNA. The messenger RNA molecule is then passed to another molecule I call the builder molecule. The builder molecule takes the messenger RNA molecule and following the instructions assembles the required new molecule. This molecule assembly process can be used to create new builder, reader, cutter, untangler, rebuilder, or any other molecule the cell needs for its life or proper functioning.
Also, that cell would need some very intricate control process. This process would need to be able to take inventory of the molecules available in the cell, tell the reader molecule(s) what new molecules are needed, monitor the nutrients available in the cell, and trigger cell division when appropriate.
For a cell to live, function, and divide the minimum requirements to start with in my opinion would include a full set of DNA, at least one reader molecule, one builder molecule, the control process, and a membrane or cell wall to hold all the parts together. That cell wall would need to be able to keep the parts of the cell together, protect the cell from dangers in its environment, and allow the cell to absorb nutrients from its environment so the cell can grow and build new required molecules. I frankly find it impossible to believe that any set of random or accidental events could actually bring all these elements together.
DNA is not just some random collection of molecules strung together. It is information coded in the sequence of molecules that make it up. No one in their right mind would ever suppose that the information in this document was somehow assembled by any random or accidental process. We all automatically assume it was assembled by some intelligent (or at least semi-intelligent) being. When I consider the amount of information stored in DNA molecules and the intricate interaction of the other molecules in even a single-celled organism, the only conclusion I can make is that it must have been conceived and assembled by a being with much more intelligence than I have.
The organism with the smallest known DNA is called Carsonella ruddii. It has just under 160,000 ‘letters’ (or base pairs) in its DNA. The Carsonella ruddii is not a candidate for nomination as the first life form on earth since it is a symbiotic organism that must live with another organism to provide some of its needs for life. The real candidates for the first life form would have in the range of 1,000,000 to 100,000,000 ‘letters’ in its DNA. For comparison this document in its current draft has around 2000 words. If the average word length is 6 characters then the total character count in this document would be only around 12,000 characters. I (as at least a semi-intelligent being) had enough trouble assembling this document without serious spelling or grammatical errors that I find it impossible to believe some random or accidental process could not only assemble the first DNA, but do it without serious spelling or grammatical errors.
Another question that a lot of people wrestle with is, “Where did the universe come from?” Most cosmologists believe that the origin of the universe was in an event they call the “big bang” where all matter in the universe was flung into space from a single point. Their assumption is that matter has always existed, all matter was somehow collected into that one point, and then a gigantic explosion occurred and set the universe into motion. The detectable motion of all objects in the universe does seem to support the theory that everything is moving away from some central point.
One difficulty with that theory is the size of the mass of that beginning point. Our universe contains objects referred to as “black holes”. These objects have so much matter in them that their gravitational pull prevents even light from escaping. It is estimated that our Milky Way galaxy alone has between 10 million to a billion black holes in it. It is also estimated that there are as many as 200 billion galaxies in the visible universe. If all of that matter were collected into a single point in space it is impossible for our finite minds to even imagine the force of gravity that would create. It is even more difficult to imagine an explosive force that would be able overcome that gravitational pull and fling the whole universe into motion.
For me a more plausible explanation is that God created all the matter in the universe at a single point in space in a single point of time. Prior to that creation moment He probably imagined all the forces necessary to regulate matter such as gravitational, electromagnetic, electrostatic, and centrifugal forces as well as all the forces that hold atomic structures together. He also imagined all of the 94 naturally occurring elements as well as how each would appear and interact. How they could be joined with other elements to form all of the molecules we know today.
Now here is the real mind blower. How many atoms of each of the 94 elements are needed to make the universe we see today? God knows those numbers. Now try to imagine all of those atoms springing into existence at roughly the same time. Each one shoving others out of the way to make room for their own space. I believe the violence of the moment of creation began the motion we see in the universe today.
As all of those atoms moved away from the point of origin the force of gravity would cause atoms to clump together to form the things we see in space now such as galaxies, black holes, stars, planets, moons, asteroids, comets, etc. Centrifugal force coupled with the force of gravity would cause smaller objects to orbit around larger ones like stars around the center of galaxies, planets around stars, and moons around planets.
When I consider the vastness of the universe and the intricacies of all forms of life from the smallest, single-celled organism to the almost limitless diversity of larger life-forms, I find it impossible to believe that it all came about accidentally. It could only be created by a being more intelligent than all of us put together. The scriptures give me the best possible explanation. God really exists, God created everything there is, and God really loves every bit of His creation, including you and me.