This year marks the 99th anniversary of the (in)famous Scopes Monkey Trial. In early 1925, the Tennessee Legislature passed a law prohibiting the teaching of any theory in public schools that contradicted the biblical account of human origins. The new law soon stirred controversy. The ACLU ran an ad looking for someone who would deliberately break the law. John Scopes, a young football coach and substitute teacher, was pushed by Dayton, Tennessee, leaders to volunteer. (One of the many ironies of the whole ordeal was that Scopes privately expressed uncertainty as to whether he had ever actually taught evolution.) His indictment jump-started what would later be called the “Trial of the Century.”

As the courtroom drama unfolded in the sweltering heat of July 1925, one young high school student testified under oath: “I believe in part of evolution, but I don’t believe about the monkey business.”

Samuel Wilkinson of the Yale School of Medicine.

As the trial drew to a close, defense attorney Clarence Darrow made the highly unusual move of calling the prosecutor, William Jennings Bryan, to testify as a biblical expert. Bryan, a well-known politician and three-time presidential candidate, was happy to oblige, confident in his ability to defend his faith even under oath. He viewed the trial — as did many — as a broader argument of science versus religion.

The examination of Bryan resulted in a painful legal renunciation of biblical literalism. From a purely intellectual standpoint, Darrow clearly bested Bryan. But he did so in a way that was mean-spirited, and the immediate media response suggested that most of the public sympathized with Bryan.

After 11 days of tense courtroom proceedings, a guilty verdict was returned. The jurors deliberated for only nine minutes (most of this time was used simply to leave and reenter the crowded courtroom). Scopes was convicted and fined $100. Bryan and the prosecution had won the trial but were humiliated in the process.

Within a week of the trial’s conclusion, Bryan unexpectedly died in his sleep. H.L. Mencken, writing for the Baltimore Sun, quipped: “God aimed at Darrow, missed, and hit Bryan instead.” Inscribed on Bryan’s headstone: “He kept the faith.”

Perhaps more than any other time in Western history, the Scopes Monkey Trial has epitomized the tension between science and religion. Many have compartmentalized how we view the world into two main categories: a scientific worldview and a religious one. When we ask ourselves how and why things behave the way they do, we invariably turn to science. When we search for answers to the deep questions of the soul, most find that science as yet provides no satisfying answers.

From subsequent study and reflection, I came to conclude for myself that evolution did not pose the challenges to orthodox religion that I once assumed it did.

This tension was thrown into stark relief in a very personal way for me. As a medical student at Johns Hopkins, I was deeply troubled by the apparent contradiction between evolution and what I had been taught in Sunday School about human nature and origins.

I remember studying, reading, reflecting and praying with great earnestness to know what was true and to be reminded of what I thought I had once believed. I still have many questions. But what I’ve learned since that time has been incredibly satisfying, both from a spiritual and an intellectual perspective. From subsequent study and reflection, I came to conclude for myself that evolution did not pose the challenges to orthodox religion that I once assumed it did.

So, here’s my best attempt to explain how, at least from my perspective, not only are evolution and traditional religious claims not in conflict, but that the way evolution has shaped our nature reflects the purpose and meaning of our existence.

Initially, there were two key dilemmas from evolutionary theory that I struggled to understand. The first is what might be called the doctrine of randomness. If evolution, as is commonly perceived, was a random and haphazard process, then it would follow that we are merely intricate molecular accidents. This view of evolution seemingly obliterates any sense of universal purpose and is hard to square with a God who intentionally created us.

A Yale doctor’s wrestle with evolution and faith

But as I studied the data, I realized that a huge amount of evidence points to evolution as a process that was not random. This line of argument comes from the way that so many creatures developed the same structures independently. For instance, birds, bats and butterflies all have wings and the capacity for flight. But biologists tell us that, through the long course of evolution, each of these creatures developed wings independently.

Remarkably similar body forms have also evolved separately. Sharks and dolphins look very much alike — they each have streamlined bodies, dorsal and pectoral fins, and countershading that makes them more difficult to detect (dark on top and light on the bottom). Yet the dolphin is a mammal with a skeleton of bone; the shark is a fish with a skeleton of cartilage. Biologists tell us that the ancestors of dolphins were land-dwelling and somehow returned to the water; the ancestors of sharks never left the water. Each evolved an eerily similar body form independently to solve the problem of how to swim fast.

Another extraordinary example of this phenomenon is the eye. Our eyes have several remarkable features: a transparent outer cover that can refract light, a lens with the ability to focus light, a diaphragm that contracts or dilates to adjust to the ambient level of brightness, and muscles that move in precise harmony with those of the other eye and adjust instantaneously to the fine tunings of the gyroscope of the inner ear. Human eyes are astonishingly similar to those of the squid. Yet, we each developed these remarkable structures independently. Altogether, biologists tell us that eyes in some form evolved over 40 times. Was this really an accident?

Given the natural laws by which the universe is governed, life as we know it may well have been inevitable.

Lest the skeptic think I am cherry-picking the best examples, it turns out that pretty much everything in biology has followed this pattern. Simon Conway Morris, a preeminent evolutionary biologist at the University of Cambridge, has remarked on this phenomenon: “I can’t think of anything which has evolved only once — or very, very few exceptions.” Even Richard Dawkins, our generation’s most outspoken atheist, recognizes that there are patterns in nature pointing to a nonrandom view of evolution. Dawkins once made this point by challenging a colleague at Oxford to name some biological features which had evolved only once. His colleague could only think of a few. Roger Thomas and Wolf-Ernst Reif phrased it this way: “While chance plays a preeminent role in setting the course of evolution, it contributes much less to the determination of its outcome.” Given the natural laws by which the universe is governed, life as we know it may well have been inevitable.

A huge amount of literature in evolutionary biology reveals higher-order principles have guided evolution to go in certain directions and to produce the same forms over and over again. There’s a lot we still don’t understand about this, and it’s important to note that the nonrandomness of evolution doesn’t definitively reconcile the theory of evolution with a belief in God and a higher purpose to our existence. But it does bring these two worldviews closer together. For me at least, it’s much easier and more satisfying to imagine a God who shaped and guided evolution through higher-order principles than a God who left the creation entirely up to chance.

If there is a universal purpose to our existence and science can offer any framework to help us deduce what it is, we need to delve into what we know about how evolution shaped human nature. This brings us to the second dilemma with which I once struggled, which is what evolution implies about humanity. In the minds of so many people, if we are really the products of evolution, then this implies that at our core we’re greedy, aggressive and self-serving.

Given the principle of natural selection (survival of the fittest), it’s easy to understand why people would assume that evolution emphasizes the darker propensities of humanity. It became advantageous for the developing human (or hominin) to hoard resources. If he wasn’t selfish enough, he risked starvation and death, while a more selfish hominin survived and propagated the trait of selfishness. Aggression can be treated in a similar manner; the evolving hominin who was too weak or passive to defend himself perished, while a more aggressive peer survived. And so we could continue with many of the negative dispositions of human nature; greed, jealousy, disloyalty, arrogance, thievery and sexual promiscuity all have their origins in the operation of natural selection. An account in the late 1800s — now thought to be apocryphal but wonderfully expressive of the sentiment felt by many — tells of a woman who, upon first hearing of the theory of evolution and its implications, exclaimed: “My dear, let us hope it is not true; but, if it is true, let us hope it will not become widely known!”

Yet over time, scientists have realized that human nature is complex. For example, even before they are able to communicate verbally, infants show a remarkable tendency to help others in need. Dozens of experiments show not only that humans are remarkably altruistic, but that we find altruism rewarding. In an experiment with children as young as 22 months, those who gave away candy were happier than those who received candy. But where does this propensity for altruism come from? How does evolution create beings who are prone to give, even to the point of self-sacrifice in extreme circumstances?

It’s complicated. But there are several evolutionary mechanisms that have pushed and pulled us in different directions. As a result, selfishness, aggression, cruelty and sexual promiscuity are unfortunate parts of human nature. But so too are altruism, cooperation, kindness and the capacity for monogamy. This is what I call the dual potential of human nature. When we combine this framework of human nature with the empirical observation that we possess free will, the purpose of our existence comes into focus with remarkable clarity. This purpose is to choose between selfishness and altruism, between aggression and cooperation, between love and hate, between promiscuity and committed pair-bonding. A fundamental purpose of our existence is to choose between the good and evil inherent within each of us. Life is a test. This is a truth, as old as history it seems, that has been espoused by so many of the world’s religions. From a certain perspective, these aspects of human nature — including how evolution shaped us — are evidence for the existence of a God, not against it.

Selfishness, aggression, cruelty and sexual promiscuity are unfortunate parts of human nature. But so too are altruism, cooperation, kindness and the capacity for monogamy.

There are several fascinating implications of how evolution has shaped our nature that are worth further consideration. One important example has to do with relationships and happiness. There is a growing consensus in the psychological community that, more than any other factor, strong relationships drive happiness and well-being. Professor Martin Seligman, the founder of the field of positive psychology, puts it this way in his book “Flourish”:

“When was the last time you laughed uproariously? The last time you felt indescribable joy? The last time you sensed profound meaning and purpose? The last time you felt enormously proud of an accomplishment? Even without knowing the particulars of these high points in your life, I know their form: All of them took place around other people. Other people are the best antidote to the downs of life and the single most reliable up.”

So where does the rewarding and satisfaction-inducing characteristic of relationships come from? I argue that, at least on some level, it must come from our evolution. In part, it’s most likely an extension of the necessarily deep and loving relationships that human parents have had to develop with their young children to ensure their survival. It’s also surely because strong social connections have always served us so well. Our ancestors likely faced a range of unpredictable challenges. Rapidly changing weather, injury and attacks from wild animals all made life extremely dangerous. Those groups and families that formed strong social connections were more likely to survive. As a consequence, deep relationships became extremely rewarding.

In sum, a great body of evidence demonstrates that relationships are the most important factor in our happiness and well-being. If evolution is responsible for this, then the closest of our relationships — our family — should have the most bearing, for better or worse, on our mental health and happiness. This is the way we have been psychologically and evolutionarily engineered. This is the way we were created.

Samuel Wilkinson is an associate professor of psychiatry at Yale University. This essay is adapted from his new book “Purpose: What Evolution and Human Nature Imply About the Meaning of Our Existence.”

This story appears in the April 2024 issue of Deseret Magazine. Learn more about how to subscribe.