Under the Microscope/Prof William Reville:Scientists, myself included, believe that life spontaneously arose on earth from lifeless chemicals almost four billion years ago, but we still have a long way to go to figure out the details of how this happened.
Many religious people believe that God directly created life, even if the subsequent development of that life can be fully explained by the scientific theory of evolution through natural selection. I will argue here that the natural spontaneous origin of life from lifeless chemicals is far the more likely explanation.
Science has shown that the material world has developed and operates in a self-sufficient manner that is fully explicable in terms of the laws of physics and of the nature of the material fabric of the universe. There is no need to invoke divine intervention to help things along the way.
We now understand how the world began about 15 billion years ago in a massive explosion of energy called the Big Bang. Ever since then, the universe has been expanding outwards from this point origin. Two of the 92 natural elements were made in the Big Bang - hydrogen and helium. Most of the remaining elements were later bred in the interiors of stars.
We understand how stars first formed as vast clouds of hydrogen and helium gas coalesced under gravity, eventually bunching so tightly that nuclear fusion was triggered to make the stars "shine". In the first generation stars, heavier elements such as carbon, nitrogen and oxygen were formed, and ageing first generation stars expelled these elements into space. We humans are made almost entirely from these hydrogen, carbon, nitrogen and oxygen atoms - literally from star-dust. The heaviest of the 92 elements were made when later generation stars exploded in supernovae.
We understand how the planets formed as material coalesced under gravity. We understand how our solar system was formed about five billion years ago. We understand in principle, although not yet in any significant detail, how life began on earth about 3.8 billion years ago, probably as a simple single form. And we understand how life evolved from that original simple form into the myriad life forms, including humans, that now occupy every environmental niche on earth.
The entire material world sequentially bootstrapped its way from pure energy in the beginning through sub-atomic particles, hydrogen, helium, stars, galaxies, the remaining 90 elements, planets, life, consciousness, and eventually to self-conscious readers of this page. This was all made possible by the nature of the laws of physics and the innate properties of matter and energy.
You have to be awe-struck at the amazing fruitfulness of the laws of nature that can explain and underpin this stupendous development. But, why are the basic fabric and laws of the universe so fruitful. There are two possibilities - either they just happen to be so, or else God designed them for the purpose of achieving the sequential development that I briefly outlined above.
NOW TO MY main point. Since, using the laws of physics, we can explain how the entire complexity of the physical universe evolved from fundamental particles and how complex life forms evolved from simpler ones during biological evolution, it is surely reasonable to extrapolate that these laws also allowed life to originate spontaneously, whether or not these laws are designed by God. In other words, whether we approach the question of the origin of life from a theistic or an atheistic philosophical perspective, we should still predict that life arose on earth by natural causes.
Life today is biochemically complex and undoubtedly much more complex than the simple form that first arose. Nevertheless, by studying life today we can make certain predictions as to the essential characteristics that the original form of life must have had. There are many scientific efforts ongoing around the world to figure out how the original cells arose from a chemical soup. Progress is being made, but slowly. I predict that the conundrum will eventually be solved scientifically, but we must wait and see.
Many readers will have heard of the recent change of mind made by Antony Flew, the English philosopher and long-time champion of atheism, who declared that he now believes in a "Designer God". Apparently his reason for changing his mind is the lack of scientific progress in explaining how the fantastic complexity of life could arise from lifeless molecules. As a believer myself, I am naturally welcoming of any atheist who wishes to change his/her mind and to join the ranks of believers. However, I think Antony Flew is changing his mind based on very dodgy reasoning.
Scientists freely acknowledge that progress is slow in elucidating how life spontaneously arose on earth, but they are optimistic that this puzzle will be solved in due course. It would be very unwise to bet against science in such a situation. So many matters have already been explained by science that once seemed to be almost impossibly difficult, for example the molecular details of heredity. Also, as I already said, it seems unlikely that a creator would design laws of physics that are almost capable, but not quite, of developing the entire world, because they cannot surmount one intermediate step. That would seem to be inelegant, indeed downright clumsy, of the creator.
Scientific explanations are usually simple once they are figured out, and this will also probably eventually apply to the origin-of-life problem. As Albert Einstein said: "The hardest thing in the world to understand is the income tax." William Reville is Associate Professor of Biochemistry and Public Awareness of Science Officer at UCC - understandingscience.ucc.ie