Why Darwin Matters (21 page)

Consider the biblical command to “love thy neighbor.” In the Paleolithic social environment in which our moral sentiments evolved, one’s neighbors were family, extended family, and community members who were well known to everyone. To help others was to help oneself. In chiefdoms, states, and empires, the decree meant one’s immediate in-group. Out-groups were not included. This explains the seemingly paradoxical nature of Old Testament morality, where on one page high moral principles of peace, justice, and respect for people and property are promulgated, and on the next page raping, killing, and pillaging people who are not one’s “neighbors” are endorsed. Deuteronomy 5:17, for example, admonishes, “Thou shalt not kill,” yet in Deuteronomy 20:10–18, the Israelites are commanded to lay siege to an enemy city, steal the cattle, enslave those men who surrender, and kill those who do not.

The cultural expression of this in-group morality is not restricted to any one religion, nation, or people. It is a universal human trait common throughout history, from the earliest bands and tribes to modern nations and empires. Christian morality, like that of many other religions, was designed to help us overcome these natural tendencies.

Much of Christian morality has to do with human relationships, most notably truth telling and sexual fidelity, because the violation
of these causes a severe breakdown in trust, and once trust is gone there is no foundation on which to build a family or a community. Evolution explains why. We evolved as pair-bonded primates for whom monogamy is the norm (or, at least, serial monogamy—a sequence of monogamous relationships). Adultery is a violation of a monogamous bond, and there are copious scientific data showing how destructive adulterous behavior is to a monogamous relationship. (In fact, one of the reasons that “serial monogamy” best describes the mating behavior of our species is that adultery typically destroys a relationship, forcing couples to split up and start over with someone new.) This is why most religions are unequivocal on the subject. Consider Deuteronomy 22:22: “If a man is found lying with the wife of another man, both of them shall die, the man who lay with the woman, and the woman; so you shall purge the evil from Israel.”

Most religions decree adultery to be immoral, but this is because evolution made it immoral. According to evolutionary psychologist David Buss, sexual betrayals are primarily a biologically driven phenomenon encoded over eons of Paleolithic cuckolding. Buss argues that there are differences between men and women in this tendency, and that these differences hold across different cultures; thus, they are primarily driven by our genes. In one study by psychologists Russell Clark and Elaine Hatfield, an attractive member of the opposite sex posed one of three questions to fellow single college students:

1. “Would you go out on a date with me tonight?”

2. “Would you go back to my apartment with me tonight?”

3. “Would you sleep with me tonight?”

The results were revealing. For women, 50 percent agreed to the date, 6 percent agreed to return to the apartment, and not a single one
of them agreed to have sex. By contrast, for men, 50 percent agreed to the date, 69 percent agreed to the apartment, and 75 percent agreed to the sex! No wonder most religions have strict codes of sexual restraint against men and repeated warnings to women about the power of the sex drive.
⁸

As for the act of adultery itself, its evolutionary benefits are obvious. For the male, depositing his genes in more places increases the probability of his genes making it into the next generation. For the female, it is a chance to trade up for better genes, greater resources, and higher social status. The evolutionary hazards of adultery, however, often outweigh the benefits. For the male, revenge by the adulterous woman’s husband can be extremely dangerous, if not fatal—a significant percentage of homicides involve love triangles. And while getting caught by one’s own wife is not likely to result in death, it can result in loss of contact with children, loss of family and security, and risk of sexual retaliation, thus decreasing the odds of one’s mate bearing one’s own offspring. For the female, being discovered by the adulterous man’s wife involves little physical risk, but getting caught by one’s own husband can and often does lead to extreme physical abuse and occasionally even death. So evolutionary theory explains the origins and rationale behind the religious precept against adultery.

Likewise for truth telling and lying. Truth telling is vital for building trust in human relations, so lying is a sin. Unfortunately, research shows that all of us lie every day, but most of these are so-called “little white lies,” in which we might exaggerate our accomplishments, or lies of omission, in which information is omitted to spare someone’s feelings or save someone’s life—if an abusive husband inquires whether you are harboring his terrified wife, it would be immoral for you to answer truthfully. Such lies are usually considered amoral. Big lies, however, lead to the breakdown of trust in
personal and social relationships, and these are considered immoral. Evolution created a system of deception detection because of the importance of trusting social relations to our survival and fecundity. Although we are not perfect lie detectors (and thus you can fool some of the people some of the time), if you spend enough time and have enough interactions with someone, their honesty or dishonesty will be revealed, either through direct observation or by indirect gossip from other observers.
⁹
Thus, it is not enough to fake doing the right thing in order to fool our fellow group members, because although we are good liars, we are also good lie detectors. The best way to convince others that you are a moral person is not to fake being a moral person but actually to
be
a moral person. Don’t just pretend to do the right thing,
do
the right thing. Such moral sentiments evolved in our Paleolithic ancestors living in small communities. Subsequently, religion identified these sentiments, labeled them, and codified rules about them.

Political conservatives can also find explanations—and foundations—in the theory of evolution. Charles Darwin’s theory of
natural selection
is precisely parallel to Adam Smith’s theory of the
invisible hand
. Darwin focused on showing how complex design and ecological balance were unintended consequences of individual competition among organisms. Smith focused on showing how national wealth and social harmony were unintended consequences of individual competition among people. The natural economy mirrors the artificial economy. Conservatives embrace free market
capitalism, and they are against excessive top-down governmental regulation of the economy; they understand that the most efficient economy emerges from the complex, bottom-up behaviors of individuals pursuing their own self-interest without awareness of the larger consequences of their actions.

Adam Smith was a professor of moral philosophy who posited a theory of human nature with competing motives: We are both competitive and cooperative, altruistic and selfish. There are times of need when we can count on the humanity of strangers to help us, but daily trade in a marketplace is founded on the lesser angels of our natures. As Smith explained in
The Wealth of Nations
, “It is not from the benevolence of the butcher, the brewer, or the baker that we expect our dinner, but from their regard to their own interest. We address ourselves, not to their humanity but to their self-love, and never talk to them of our own necessities but of their advantages.”
¹⁰
By allowing individuals to follow their natural inclination to pursue their self-love, the country as a whole will prosper, almost as if the entire system were being directed by . . . yes . . . an invisible hand. It is here that we find the one and only use of the metaphor in
The Wealth of Nations:

Every individual is continually exerting himself to find out the most advantageous employment for whatever capital he can command. . . . He generally, indeed, neither intends to promote the public interest, nor knows how much he is promoting it. He intends only his own security; and by directing that industry in such a manner as its produce may be of the greatest value, he intends only his own gain, and he is in this, as in many other cases, led by an
invisible hand
to promote an end which was no part of his intention. By pursuing his own interest he frequently promotes that of the society more effectually than when he really intends to promote it.
¹¹

Compare this to Darwin’s description of what happens in nature when organisms pursue their self-love with no cognizance of the unintended consequences of their behavior:

It may be said that
natural selection
is daily and hourly scrutinising, throughout the world, every variation, even the slightest; rejecting that which is bad, preserving and adding up all that is good; silently and insensibly working, whenever and wherever opportunity offers, at the improvement of each organic being in relation to its organic and inorganic conditions of life. We see nothing of these slow changes in progress, until the hand of time has marked the long lapses of ages, and then so imperfect is our view into long past geological ages, that we only see that the forms of life are now different from what they formerly were.
¹²

Evolution provides a scientific foundation for the core values shared by most Christians and conservatives, and by accepting—and embracing—the theory of evolution, Christians and conservatives strengthen their religion, their politics, and science itself. The conflict between science and religion is senseless. It is based on fears and misunderstandings rather than on facts and moral wisdom. Indeed, for the benefit of our society, the battle currently being played out in curriculum committees and public courtrooms over evolution and creationism must end now, or else, as the book of Proverbs (11:29) warned:

He that troubleth his own house shall inherit the wind: and the fool shall be servant to the wise of heart.

There are known knowns. There are things we know we know. We also know there are known unknowns. That is to say, we know there are some things we do not know. But there are also unknown unknowns, the ones we don’t know we don’t know.

—Donald Rumsfeld, United States Secretary of Defense, press conference statement on February 12 (Darwin’s birthday), 2002

On September 18, 1835, H.M.S.
Beagle
dropped anchor in the Galápagos archipelago at the base of Frigatebird Hill on Chatham Island, now known as San Cristóbal. Blue-footed boobies circled about the bay, and at the appropriate moment tucked their wings back and sliced into the shallow sea to scoop their prey from schools of thousands of tiny fish. Earning their moniker, the frigatebirds perched high on the cliffs above, poised like pirates to pounce on the boobies and steal their catch.

Charles Darwin’s first impression of this island was “what we might imagine the cultivated parts of the Infernal regions to be.” Vast swatches of black volcanic rock and countless extinct cinder cones were punctuated with scrappy life forms suited for here and
nowhere else. Most striking to Darwin were the marine iguanas that swarmed the rocky beaches of the northern regions of the island:

The black Lava rocks on the beach are frequented by large (2–3 ft) most disgusting, clumsy Lizards. They are as black as the porous rocks over which they crawl & seek their prey from the sea.—Somebody calls them “imps of darkness.”—They assuredly well become the land they inhabit.
¹

When Frank Sulloway and I hit the beaches of San Cristóbal 170 years later, we searched in vain for Darwin’s imps. In their stead we spotted feral cats darting in and out of the black boulders, the largest, fastest, and stealthiest cats imaginable. The adult marine iguanas are too large and leathery for the fugitive felines, but the juveniles make easy targets. Without a juvenile cohort to maintain a viable breeding population, the iguanas suffered geographic extinction.

Frank and I reported this glum news to our colleagues at the 2005 World Summit on Evolution that was being held on a coastal outskirt of the lively little fishing town of Puerto Baquerizo Moreno, adjacent to Frigatebird Hill.
²
With 210 of the world’s leading evolutionary biologists in attendance, the conference illuminated the greatest unsolved mysteries of evolution.