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On the (Divine) Origin of Our Species

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By Darrel Falk

Part I. God is Love

We humans are primates. Although our bodies may be like other primates, we alone are the species of music, art, poetry, drama, laughter, teaching, science, reason, and mathematics. What makes this possible is our communal mindset. We have developed a remarkably sophisticated, highly communicative way of life not found elsewhere in the animal world.

Chimpanzees are our closest living relatives. Our respective lineages each stem from a single ancestral species which lived in Africa about six million years ago. Based on the similarity of the many traits we share with chimpanzees, we can assume that in some ways very little has changed. We each have the same set of bones and muscles, and they are all arranged in much the same way. We share the same physiology, and our cellular biochemistry is almost identical. However, behaviorally we live in two different worlds. Something happened on the way to becoming human. Many scientists think it was our effectiveness at teaming up—our skill at understanding each other’s mindsets and thinking together as a unit—that set Homo sapiens on a new course. It proved to be stunningly successful.

Two hundred thousand years ago as our species was coming into being, we shared space on the planet with at least five other closely related hominin species (hominins are all members of the related set of species on the lineage that includes us). Indeed, the presence of multiple closely related species on our family tree has been the rule, not the exception, for most of the past six million years. It is only in the last 40,000 years (less than one percent of our family tree’s existence) that it has been winnowed down to just one. Why just one, given that the others shared most of the same physical characteristics? They could run long distances and had brains at least as large and dense as ours. They were successful hunters, had fire, and could use it to cook meat. The growing consensus is that members of our species were becoming master-communicators. We were connected to each other in a way never-before realized. But that just raises one more question—how in the world did this come about?

Many scholars think that one of the most remarkable characteristics that sets humans apart from other animals is our full theory of mind. We alone have the capacity to fully appreciate the enriching ramifications of others having a mind like our own. Investigators don’t know when this happened in our lineage, but it likely came to full fruition only in our species. To catch a glimpse of what a difference this would have made, consider the stages of development that our own children go through as babies become toddlers and then on into childhood. It is not until the ages of four to five that children really start to think about the thoughts and feelings of others. (This essay provides a nice summary of the various stages.) Evolutionarily speaking, something analogous to our children’s acquisition of a full theory of mind happened in our own ancient ancestral lineage eventually reaching its zenith in Homo sapiens.

As parents we deeply love our children from the moment they are born, but we express that love differently for babies, who understand little, than we do for ten-year-old children, who are becoming socially aware. The latter understand the consequences of their actions, and parents can lovingly encourage them to make wise choices that are considerate of others. Babies don’t understand that at first—they don’t even have a concept of others having a mind too. But as they begin to understand the social dynamics of their existence, our love for them takes on a new dimension, one oriented towards helping them to thrive in a world where others have needs and desires too. Throughout the development of our babies and children, our love is a constant presence, but how we exercise that love changes, as it seeks to keep in step with their changing minds.

Let’s think about this theologically as it relates to God’s parental love in the development, not of babies into children, but of members of our ancestral lineage becoming human. As they moved into an increasingly mature and fuller understanding that others have a mind and feelings just like their own, God’s love for them reflected that. Scripture emphasizes God’s parental love. In Isaiah 49:15, God’s love is put into a maternal framework: “Can a woman forget her nursing child or show no compassion for the child of her womb? Even these might forget, yet I will not forget you.” Jesus, reflecting on Jerusalem, declares: “How often have I desired to gather your children together as a hen gathers her brood under her wings, and you were not willing!” (Matt. 23:37) God yearns for relationship. Perhaps the most-defining parable Jesus ever told is that of a longing parent, the father, who runs out to meet and joyfully welcome his lost son back into his home. Jesus is showing us in the most profound way imaginable that this is what God’s parental love for humankind is like.

John Wesley, who knew nothing of evolution of course, believed that “there is no human being who has ever existed who was not deeply loved…Thus no human being lives without the Spirit wooing to live compassionately and justly with (all) others” (taken from p. 82 of Michael Lodahl’s Matthew Matters). Just like the love we have for each of our children begins even before the moment of birth, so too we can anticipate that God’s love for members of our ancestral lineage was always present. Just like we parents love our infants more than we thought humanly possible, so it would have been with God’s love regardless of the primitive nature of those early hominin minds.

God’s love was constant, but there was something that was changing over the millennia: The capacity of individuals to understand the hopes, needs, and desires of other persons was undergoing a dramatic shift. Their increasingly social mindset was enabling them to knowingly choose between a disposition focused only on gratifying their own immediate self-centered desires, and one focused on the needs and desires of their immediate neighbors too. They were gaining the capacity for empathy. They could choose to be sympathetic—or not.

The process of developing a full and increasingly sophisticated theory of mind likely stretched out over tens of thousands of years, but if God is love and if that love is parental, surely God would have been seeking to nurture God’s kind of love into their little communities. God would have wanted them to experience the joys of harmonious living as they faced the wild challenges that existed on those open savannas and elsewhere in Africa. James 3:17 states, “The wisdom from above is first pure, then peaceable, gentle, willing to yield, full of mercy and good fruits without a trace of partiality or hypocrisy. And the fruit of righteousness is sown in peace by those who make peace.” That’s what God would have wanted for them.

What if there was at least one community—one small group of individuals who actually lived this way for multiple generations? Regardless of what they understood about the ongoing “wooing of the Spirit,” let’s say that the individuals in this group chose to live according to the Spirit who was prompting them to always act lovingly. What would happen? Computer simulations have clearly demonstrated that as long as there exists something that effectively keeps selfishness in check, the existence of such a group is a much more successful evolutionary strategy than a group where individualism is not kept in check.

Our ancestors were never alone. They were always deeply loved. If there was a small group that sensed this in some way and chose to live into that love, that group would thrive and be an evolutionary success story. Would geneticists predict that such a lifestyle could over time bring about a set of gene-changes that would facilitate this lifestyle even more? That’s the question we approach in the next article.

Part II: Responding to God’s Love (or Not)

As we saw in Part I, computer simulations can tell us a lot about successful strategies in evolution. For example, they show that when two small groups are competing for survival, a unit of fully cooperative individuals will outcompete a comparable unit where selfishness is present. Now in Part II, we will examine this concept with living animals rather than simulated ones.

Consider a set of experiments by William Muir at Purdue University. He ran two different selective breeding regimens to determine how best to improve egg laying in chickens. In the first, he selected the most productive egg-laying hen in a cage of about seven chickens. He then bred from her and selected her most productive daughter. Placing her in a cage with seven of her sisters, he repeated this, and continued to repeat the procedure for several more generations—always choosing the most productive daughter in a cage. In the second experiment, he bred for the most productive group of hens. From a whole set of cages each with about seven hens, he chose the group that produced the most eggs. He then bred from the winning group, and divided up all the daughters into a new set of cages—each with about seven sisters. Again, he chose the most productive cage. After repeating this for several more generations, he had a highly successful group.

The difference in results between the two experiments was remarkable. In the first, the overall productivity of a cage went down even though it contained a “super-hen.” In the second, where selection was based on the most productive group of hens, productivity went up 160 percent. The two figures say it all. By selecting for the most productive individual, the end result is a line of bullies. These individuals succeed by harassing, pecking at, and even murdering other hens in the cage. Apparently when selecting for the most productive individual, the winning strategy was to have a set of genes which cause really selfish behavior. When selecting for the most productive group, the winning strategy stems from having a set of genes that bring about harmony, not discord. These really were changes in the genetic constitution of the hens: they were heritable from one generation to the next.

Here is another example. In 1959, a Russian geneticist began an attempt to tame red foxes. To produce this line, he chose to breed only from the individuals that were the least aggressive in their interactions with humans. Year after year he repeated this breeding procedure. By the 1970s the foxes in the selected line were wagging their tails in excitement as their caretakers approached. In complete contrast, individuals in the unselected control line barked and nipped in dismay as humans drew near to their cages (see a video showing the difference, starting at 4:38). A whole new type of fox had been created, one that now had a set of genes expressed in a way that enhanced friendliness and suppressed aggressiveness. It wasn’t a new species by any means, but it did have a significantly different genetic makeup.

In Part I, I mentioned that many investigators think that what set Homo sapiens apart from its cousin hominin species was that individuals were successfully functioning as a unit. I ended with the question: What would happen to the genes in a small population if they lived harmoniously for multiple generations? In other words, would there be a heritable difference in characteristics in a group that lived in accord with the “wisdom that comes from above?” Based on the sorts of experiments discussed above, I think we can say that gene expression favoring increased sensitivity to others would come to predominate in this type of population.

With all of this in mind, here are a set of principles which I think illustrate how the activity of God’s Spirit brought our species into existence.
Principle 1: God is love and God’s Spirit is the source of all genuine love.
Principle 2: Regardless of whether they knew its actual source, a population where love flourished started to respond to the ongoing activity of God’s Spirit.
Principle 3: That population started to thrive.
Principle 4: The population lived like this for at least a few hundred years.
Principle 5: Heritable changes in gene expression which facilitated harmony increased in the population.
Principle 6. The Spirit of God, in partnership with members of the population brought a whole new way of being into existence.

I am not suggesting that this happened only once. It may have happened multiple times and even in different places as our species was coming into existence. What I am suggesting is that core precepts of evolutionary genetics predict that this is what would happen under the above conditions.

Let’s examine the genetics just a little further. Darwin began his book on the theory of natural selection with an extensive discussion of how humans had been able to produce new strains of pigeons by artificial selection. His point was that if humans could select for and produce all sorts of different pigeon lines, natural forces could do much the same thing to living organisms in general. Indeed, given a long enough time, whole new species could be produced through natural selection.

In building his case for the power of selection, Darwin went on to suggest another example of how he thought humans had likely brought about evolutionary change. This next example pertained to the origin of dogs. He didn’t know the details then, but today, through genomic investigations, we know quite a bit. All dogs arose from two different wolf populations. The wolves probably lived by scavenging whatever food they could get from the human communities near which they lived. Given such a lifestyle, there would have been a clear advantage to any wolves who were tamer. Gradually, by becoming tamer and tamer over the generations, wolves evolved into dogs. A whole new species and, indeed, a whole new way of living developed. Dogs had become humans’ “best friends.” Given the above principles, something analogous to this can account for the origin of our species as well. If one or more small populations chose to respond positively to the gentle nudges of God’s Spirit for a long enough time, we would expect a new way of being to emerge.

The bottom line is that living in synchrony with the Spirit of God for many generations would foster genetic change. That change would be analogous to what happens to gene expression in animals as their genetic constitution is altered by human activity. This, were it not for adding in the activity of the Spirit of God, is the equivalent of “Evolutionary Biology 101.” But, if the God of Christian theology is real, it is what the science of Genetics teaches us would happen.

Part III: A New Way of Being

In Part II of this series, we saw that a set of principles grounded in both theology and evolutionary biology could explain the origin of our species. The most noteworthy quality that characterizes our species is our ability to understand and communicate effectively with one another. It is not hard to envisage what sort of genetic changes would enable us to become more attuned to one another’s minds. Here are a few examples of what has happened to enable members of our species to break into a whole new realm of being:

  • Genetic alterations have occurred that have enhanced the ability of facial expressions to reveal one’s emotional state. Thick brow ridges, for example, are largely gone and facial bone structure is finer compared to that of our ancestors. These are among the facial changes that led to an increased ability of individuals to understand what the other person is thinking.
  • Genetic changes took place which dampened aggressiveness and reduced hurtful emotional outbursts. These genetic changes altered the adrenal gland and the brain. Tweaking of this sort facilitated our ability to function well in group activities.
  • Genes were changed in a manner that expedited language development. This included changing the shape, musculature, and nerves of the vocal tract. These alterations improved the ability to communicate one’s thoughts, in addition to helping understand the thoughts of others.
  • Genetic changes altered the brain in a manner that led to improvements in generating specific sounds and enhancing our ability to discern subtle differences in speech enunciations.

This is not an exhaustive list by any means, but it gives you a feeling for how our species has changed to enhance social cohesiveness. What follows is one more example that I want to discuss in a little more detail.

Thanks to the work of Francis Collins and many others, we know the coding (DNA) sequence of all the genes of our species. We also know the sequence of our most closely related extinct cousin species—the Neanderthals and Denisovans. Studies are underway to pinpoint many of the specific coding changes which have led to our unique lifestyle. It is now apparent that those changes will largely turn out to be alterations in the regulation of gene expression. In other words, the primary changes have altered where, when, and how frequently particular genes are expressed (see a two-paragraph primer on gene expression in this BioLogos article). It is going to be very interesting to know the specifics, but we now know enough about what we can expect, that I’d like to give you a little feeling for what is on the horizon.

Much of what we know about the nature of gene expression comes from studying what happens to body or mind when a gene functions abnormally. What follows is an insightful example of how fine-tuning of gene expression can affect human sociality. About 200 babies are born each year in the United States with a genetic abnormality called Williams Syndrome (WS). These individuals carry a tiny deletion of about 26 of the 1,000 or so genes on Chromosome #7. Except for the sex chromosomes of males, we normally have two copies of each gene (one from each parent). Persons who carry this deletion, however, have only one copy of the 26 genes. That reduction from two to one means that each of these 26 genes is expressed at only about fifty percent of its normal level. This lower level of expression has a variety of consequences. For example, WS individuals are outgoing, have engaging personalities, and tend to take an extreme interest in other people. Sadly, they also frequently have attention deficit disorder (ADD), problems with anxiety, and phobias. Likely one of the 26 genes functioning at the 50% level is the cause of these changed social attributes.

Often in human genetics, an investigator needs to turn to a model organism in order to understand more fully what a particular gene is doing. Frequently the laboratory mouse serves this purpose. Mice have the same set of 26 genes all linked side-by-side. Behavioral studies show that when mice carry only one copy of these 26 genes rather than the normal two, they become hypersocial, much like humans. Indeed, it’s been possible to identify which one of the 26 genes is responsible for that hypersociality. It turns out that this same gene has also been altered in the evolution of dogs from wolves. Hence, this change may have played a role in the increased friendliness of dogs as well.

In humans, sometimes an individual is born who has three copies of this 26-gene region instead of the normal two. Such individuals, likely expressing the gene at 150 percent of the normal level, have the opposite personality compared to the highly social WS individuals. They are frequently anti-social and autistic. Here is the point I want to make: In this tiny region of Chromosome 7, there is a gene, the expression of which is normally set at a level for optimal sociality. If it is expressed at too low a level individuals may be overly sensitive in their interactions with others, often in a way that leads to ADD and anxiety. On the other hand, if the expression level is too high, an anti-social disposition is the result. So, the evolutionary process has likely set the expression level of this gene at an optimal level. Given that this is just one of the genes affecting sociality and there are likely many more, we can picture a selective process at work influencing the level of expression of all of them.

In my book, On the (Divine) Origin of Our Species, on which this series is based, I discuss more of the nuances of these scientific claims, and then outline some of the theological ramifications of the view of human origins I have described here. Fundamental concepts such as the Fall and Original Sin remain intact. Indeed, I think they are actually augmented as we understand the concepts within the context of this melding of evolutionary science and theology. In one of my favorite books on science and theology, Darwinism and the Divine, Alister McGrath makes a point that I think is highly relevant to this work. He writes that Christian theology provides a set of “theoretical spectacles which allow us to behold things in such a way that we are able to rise above the observable and move into the richer realm of discerned meaning and value” (p. 289). Never has the science of human evolutionary biology provided greater potential for the “beholding” of which McGrath speaks. Moreover, since the “spectacles” have largely been ignored or deemed fantasy by almost all human evolutionary biologists, I think the “beholding-task” has become urgent. It is important for us to put our spectacles on and see humankind for who we really are. We are not the product of an impersonal process. We were nurtured into existence through the enduring and empowering love of God. The study of God’s Word provides timeless theological truths. But the study of God’s world ensures that these timeless theological truths are providing 21st century answers to 21st century questions.