Tertullian, a second century Christian, in struggling to defend his view of orthodox Christianity, wrote that the questions that make people heretics are: "Where does humanity come from, and how? Where does evil come from and why?" For me, these are important questions. The search for answers has led me to embrace many heresies, one of which is evolution.

The Theory of Evolution

The word "theory" gives a false view of evolution to many. It suggests that evolution belongs to the realm of the hypothetical and untested. Evolution is often denigrated by the statement: "Evolution is only a theory." Most scientists would agree that a theory is a more or less verified explanation accounting for a body of known facts or phenomena. Examples of this would be atomic theory (matter is made up of tiny particles), plate tectonic theory (the continents drift slowly across the surface of the earth floating in liquid rock), and Copernican theory (the earth goes around the sun rather than vice-versa). These theories, evolution included, are considered well established by the scientific community. Since science never produces absolute certainty - the door is always left open for new ideas, observations and explanations - we can only appraise its truth in probabilities. From my assessment of the scientific literature, most scientists would place the probability well above 90%.

When I say that evolution is well established, I mean that it has been vigorously tested, and there is a large body of evidence to support it. I challenge any person who has not carefully examined the huge accumulation of evidence to do so.

The idea of evolution is so important that it should be the responsibility of every person who seeks to live an enlightened life to examine the evidence themselves. This is an area where blind faith is particularly dangerous.

The principal critics of evolution are fundamentalist Christians, and their arguments are as much anti-science as they are anti-evolution. The fundamentalists have worked hard through the 20th Century to keep the teaching of evolution out of public schools. In a legal sense they have failed as of 1992. To my knowledge there is no legal or administrative barrier to the teaching of evolution anywhere in the public schools of Utah. Most popular textbooks treat the topic adequately.

Here in Utah evolution is an important segment of the biology curriculum. That doesnt mean evolution is well taught everywhere. Many teachers fudge because of their own inadequate training, personal reservations, or priorities. Encouraging teachers to teach evolution is a worthwhile goal of humanism.

How Evolution Works

DNA is a chemical found in living cells, and has the coded instructions for how to carry on the workings of life, and how to make a new individual in the process of reproduction. DNA is a stable compound, and rarely makes a mistake in copying itself when cells reproduce. Mistakes in copying, and changes in the DNA do occasionally happen. These alterations produce new variations in the organism as the new instructions in the DNA are carried out. These mistakes are called mutations, and most produce debilitating effects. Once in a very great while a new mutation will change the DNA code to make a new trait better than the old one. This prolonged accumulation of beneficial mutations accounts for the ponderous slowness of evolution. Whether a trait is better or not is completely relative to the organism's environment. Traits that aid the ogranism in the struggle for survival are passed on through DNA to their offspring. New traits that are maladaptive are passed on to new generations less frequently because individuals with these traits are less likely to leave as many offspring and consequently these traits disappear. This process, called natural selection, was the discovery of Charles Darwin in the 19th century. The role of mutations and DNA in evolution are 20th century discoveries. Modern science has extended and verified the work of Darwin.

The History of Life on Earth (a very short version) or From Hydrogen to Hamlet.

In the beginning was the Big Bang. It sent the element hydrogen rushing everywhere in the universe. The hydrogen condensed by mutual gravitational attraction into stars. Some stars were unstable and these supernova blew themselves apart. This vast release of energy caused the transmutation of hydrogen into heavier elements. Our corner of the universe is rich in these heavier elements, and our star, the sun, is a second generation star made partly from the exploded bits of supernova. The earth also condensed out of this primordial star dust which explains the presence of the relatively rare elements of sulfur, phosphorus, oxygen, nitrogen, and carbon. Add to these the ever abundant hydrogen, and naming them by their first letters, we have the stuff of life: SPONCH. Scientists have discovered over the last 30 years that SPONCH does interesting things if we put it in the simulated conditions of the primeval earth's environment (or the present conditions of the planet Jupiter). The SPONCH, using the sun's abundant radiant energy, assembles itself into the basic molecules of life: amino acids (the components of proteins), hydrocarbons (the components of fats), sugars (the components of carbohydrates and DNA), Purines and Pyrimadines (the components of ATP, DNA and RNA).

How the first reproducing cell came to existence is speculative since the fossil record from over 4 billion years ago is sparse, and the molecular bits and pieces decomposed long ago. The first undisputed artifact of life to appear in the fossil record is a single celled photosynthetic prokaryote dating back 4 billion years. The progress of life from this time on is documented in the fossil record: an unambiguous history of evolution.

In a layered column of sedimentary rocks - such as the one visible from the rim of the Grand Canyon - the oldest rocks lie at the bottom, and the youngest at the top.

The fossils in the rock layers chronicle that which lived on the earth in each successive period of time. No matter what rock column you observe from any part of the earth, a similar pattern is seen. This sequence of appearances is called the law of faunal succession. The greedy exploration for oil and other minerals has given us extensive data on this matter.

In what order did animal life appear? First there were single celled protozoans; then sponges, jellyfish, worms, tunicates, lancets, lampreys, fish, amphibians, reptiles, mammals, primates, apes; and last of all humans. Each step adds tiny modifications (mutations) slowly moving toward greater complexity. Donald Johanson documents the last step, from primates to humans, in his excellent book, Lucy: The Beginning of Humankind.

What a Journey: We are star-dust that has become aware of itself!

Is Evolution Consistent With Judeo-Christian Theology?

Some of my students attempt a truce between their religion and evolution by saying, "Well, that's how God created us." I generally do not pursue that statement in class; it would compromise that important principle enshrined in the U.S. Constitution that creates a separation of Church and State. As a public school teacher I am on firm ground teaching evolution because it is good science, but I am out of bounds if I attack a students religious faith. The idea that evolution is God's instrument of creation makes sense if you use Albert Einstein's definition of God. He said, "God is the sum total of the laws of the universe." Obviously this is not the personal God most people believe in: one that hears and answers prayers, comforts and supports us in hardship, and consoles us in the death of a loved one.

The personal God of Christianity combines with evolution about as well as oil and water. If God is merciful how can He be the author of evolution with its 4 billion years of suffering and death generated by the struggle for survival? And remember that the adaptable shall inherit the earth, not the meek. If God is omnipotent, why were 99% of His creations doomed to extinction, like the dinosaurs and trilobites? What is the meaning of the dinosaurs? Were they a 175 million year doodle on the drawing board of creation? And why does God like beetles, flies and mosquitoes so much, since He made so many kinds of them?

I also believe it is useless to try to reconcile the book of Genesis with evolution. It says that the Fall of Adam brought death and suffering into an otherwise perfect creation. But evolution shows that death and suffering were here long before Adam. How can we reconcile death and suffering with God's supposed goodness and omnipotence? And did Adam have parents? If so, it is reasonable to presume that they were as human as Adam? Do they qualify for salvation through the redemption of Christ? What about Lucy, that 4 million year old anthropoid from East Africa? What about house flies, beetles and dinosaurs: do they get resurrected too?

Where do you draw the line? I understand that many main line Christian denominations have tacked evolution on to their theology, but I don't understand how they make it consistent.

The Meaning of Evolution

Some people look at the sequence of the appearance of life forms on earth, and conclude that nature from the beginning intended to make a human, the end product and pinnacle of evolution, endowed with power to lord it over all the rest. I believe such a view is teleological, self centered nonsense. It ignores the fact that mutations are random accidents. If we trace the line that leads to dinosaurs, tumbleweeds, house flies, dung beetles, and tape worms, also end products of evolution, would we conclude that they are also the pinnacle of evolution? The metaphor for evolution of a ladder climbing rung by rung toward humankind is poor.

A better metaphor is a single massive tree with millions of end branches, each a present day species, of which humankind is only one tiny twig.

Here lies one of the most profound meanings: all life is one. All humans are brothers and sisters, and even the whales and roses are our cousins. Humankind is not separate from nature: we arose from nature, and are a part of nature and are still governed by the laws of nature. All life is worthy of our respect, and other life forms have as much right to live on this planet as we do.

Evolution is purely opportunistic and unplanned: it uses whatever useful changes that come along. The statement "the survival of the fittest," a phrase coined by the economist and philosopher John Stuart Mill, is misleading because it suggests evolution always provides the best possible alternative. A better description is survival of the fitter, since evolution will use any change, no matter how imperfect, that fosters survival and will discard all others. Richard Dawkins describes these oblivious wanderings of evolution of in his book The Blind Watchmaker: Why the Evidence of Evolution Reveals a Universe Without Design.

Some people encountering the idea of human evolution despair that it demans humankind. It does humble us somewhat, just like the Copernican theory kicked humankind off the center of the universal stage. Others belittle evolution by saying: "How could humankind be just an accident, just a chance permutation?" Some will ponder the future of humankind and conclude that if we appeared by chance we could disappear by chance. These thoughts give rise to feelings of uncertainty and existential anxiety, so it is understandable that many people feel a need to deny evolution, or at least dilute it a bit.

The knowledge of evolution does not diminish my esteem for humankind. We are the same astonishing creature that poets and scientists have always marveled and puzzled about. We are still unique among all the species that evolution produced on this planet: we are the ones who can understand and contemplate the process that gave us life. It is reasonable to believe that evolution elsewhere in the universe may also have given rise to sentient beings, but at present there is not a particle of evidence to support that conclusion. What if indeed we are the most organized form of matter in the universe? What a destiny! What a Responsibility! Evolution suggests to me that there is not an ultimate purpose for my existence, but I have discovered within me a marvelous power: I can create my own purpose for existing, and I'm exuberant with the possibilities!

Getting an accurate picture of who we really are is an important task. The work of anthropologists, paleontologists, sociologists, psychologists, biologists, etc. is essential. Evolution cannot provide a model for human ethics since it is amoral. We need the knowledge culled from the study of humankind to help us wisely construct our ethical systems, erect our institutions, shape our attitudes, sort our values and solve our problems. Our best hope for a system of ethics that will work will be rooted in our experience and our knowledge about human nature.

Is evolution still occurring, some wonder? Most likely, but it is so ponderously slow we cannot count on it to get us out of our present difficulties. Unfortunately, evolution has left us far from perfect creatures. Cultural evolution, the kind of changes we make with our hands and our brains through technology is a much faster kind of evolution. Technology is always a mix of good and bad, and it is moving at an exponentially increasing pace. It is exhilarating, but dangerous, like riding a tiger. Lately, humans have learned to tinker with their own DNA. We may be on the verge of directing our own evolution!

The lesson of the dinosaurs suggests that even if we are the top of the heap for 175 million years, our survival is not guaranteed. We have one characteristic that makes us so successful: our brains. It's a cinch we're out of here unless we use them.

Most humanists do not need a recounting of the multitude of difficulties we must surmount if we are to survive. One of the ways to create meaning is to take on these problems, and do something about them!

--Richard Teerlink