Genes, Human Evolution, and the Coming of Civilization

There's a fascinating new series on Slate: Blogging the Human Genome. It's surprisingly good. It considers some things like whether men will go extinct , whether an STD-like virus drove human evolution, and how close the human race came to going extinct (evidence says maybe down to a few thousand adults).

This entry begins talking about the fact that perfect pitch is more prevalent among the Chinese whose language is tonal - the pitch changes the meaning of the word. Because children grow up in that culture, the genetic basis of perfect pitch is activated more often than it is in European cultures where pitch is less important, at least to those who do not wind up studying music at an early age. It then goes on to talk about how the cultivation of yams gave rise to sickle-cell anemia. In the process, it makes a larger point about how human genes have been transformed over the last few thousand years of human cultural adaptations:

One profound example of co-evolution involves chromosome 11. Thousands of years ago, various tribes in West Africa began clearing out the dense, ancient forests near their homes and cultivating plots to grow yams and other crops. Their strategy worked well—the yams thrived, becoming a dietary staple—but had an unintended side effect. The old forests had slurped up excess rain quite well; the bare farmland did a poorer job, and left standing pools of water that attracted hordes of mosquitoes.

Mosquitoes harbor diseases, especially malaria, which became endemic among Africans there, and the tribes had to come up with genetic defenses to survive. One mutation in particular seemed to help, an A→T swap on the hbb gene on chromosome 11. This mutation changed the shape of some red blood cells, making them less like a disc (the normal shape) and more like a crescent. This in turn helped prevent malaria, which parasitizes red blood cells, from getting a foothold. As a result, the mutated hbb gene began to spread in the region, following the clear-cutting yam farmers wherever they expanded.

Unfortunately, when the mutated, crescent-cell-producing gene became relatively common, people started having children with two copies of it. And while having one copy still provided resistance to malaria, having two copies proved deadly, since the crescent, or sickle-shaped, blood cells died off prematurely, and also jammed up inside small blood vessels. Today we call this condition sickle-cell anemia. The hbb mutation never would have wreaked such havoc among these tribes if not for the ancient decision to farm yams so intensely.

Cultural choices have expanded or contracted many other genetic traits as well. Different prehistoric diets (including the introduction of cooking) probably changed our teeth and jaw structures, farming starchy foods probably intensified the concentration of certain enzymes in our saliva that digest starch, and domesticating cattle and other milk-producing animals probably led to what by all rights should be called lactose tolerance (not lactose intolerance, since adults who can digest milk are the mutated weirdos). Many superficial human features, like eye color, also responded strongly to cultural cues about what different groups found attractive. In fact, modern civilization has curbed the ancient threats to our survival—exposure, droughts, starvation, predators, parasites—so well that culture probably shapes our genes as much or more than anything else nowadays.

Blogging the Human Genome. Entry 14: How yam farming contributed to the rise of sickle-cell anemia. (Slate)

And this leads me to articulate a theory I've been working on for a while, but have been unable to articulate. But since the above article directly related to it - specifically how society shaped human genetics, I will try and articulate it now, even though it's not very well-formed and in rough sketches. Sorry in advance for the choppiness and incoherence.

We must first accept that there is a strong genetic component to authoritarianism. By authoritarianism, I simply mean the fact that we listen to what “they” say. The fact that we are forced to act against our own will because everybody else is. We are forced to go with the herd – because we will be sanctioned if we do otherwise. But why is there a herd at all, in other words, why do human beings engage in this bizarre behavior that seems so against their self-interest? How could city-states form when people could just reject it in favor of a better alternative? Why do we see the rise of leaders being worshiped as gods and hard-earned grain taxes paid to temples because some distant priesthood “commands” them to do so? And why do we see this behavior even in the absence of direct military compulsion (you would need as many soldiers as subjects)?

My theory is that civilization formed from the bottom up – when authoritarian genes became dominant in the population. This occurred because cultures with large number of authoritarian followers were able to act coherently – in a “hive mind” so to speak, and militarily conquer peoples whose members were more able to reject hierarchical authority and think for themselves.

The Bible is practically a narrative of this dynamic – the Semitic Hebrew tribe conquers people after people in Iron Age Palestine, slaughters all the men and children and impregnates the women. They are told to do this by their God (the same God worshiped by Christians today, incidentally), who rules over them in a rigid class hierarchy. Thus they are able to pass along their authoritarian genes and eliminate the genes of the societies less able to resist their military onslaught for whatever reason (less cohesion, less institutions, less martial farvor, etc.). This process probably happened even earlier among the ancient city-states of Mesopotamia, where the Hebrew tribe and the stories of the Bible got their origin.

Essentially, man self-domesticates. Man is domesticated the same way any other animal is – by selective breeding. This is done by culling specific traits and selecting for others. They key is – and this is essential – it is human society which has done this, not a higher intelligence with a specific intent in mind such as man’s domestication of the cow or the dog. While the cow was designed by man for docility and the dog for submission and loyalty, civilization domesticated man to be a follower, with all of the cognitive blind spots this entails.

Human culture has transformed humans into herd animals, or sheeple – docility accepting the will of the alphas and accepting whatever unjust social systems exist, no matter how ridiculous or absurd. It took several thousand years for this process to occur, which explains why settled domesticated life began about fourteen thousand years B.C., but city-states and large-scale societies only begin to emerge about 4000 B.C., and spread rapidly from there. This is how long it took for authoritarians to become the dominant form of humanity and individualist genes to be sufficiently purged. Early agricultural villages like Catal Huyuk and Goblecki Tepe in Turkey show little signs of hierarchy. A few millennia later in places like Ur and Babylon, man’s spiritual inclinations had been hijacked by a dominant priesthood interceding between man and his tribal gods, and we see the emergence of kings, slaves, temples, taxes, and armies.

The Bible is practically a documentation of this effect. Consider the story of God ordering Abraham to sacrifice his son Isaac. Here Abraham is so dedicated to following his invisible sky God that he is willing to cut his first-born son into little tiny pieces. In the end it’s just a test – God is making sure that man is the unquestioning follower he needs to command to bring about the success of his “chosen” people.

People who thought for themselves were less able to form armies and thus resist the onslaught of the authoritarian tribes who blindly followed the leader, essentially always on the basis of a religious affiliation. Such people were culled in the domestication sense – their genes were not passed on. The authoritarians, by contrast, were able to breed prodigiously. They were allowed to breed because they followed orders. It makes sense – how many people who went against the grain in history were rounded up and tortured or killed for their beliefs, while people who sided with the majority stayed out of trouble? Certainly following the pack was a better way to get your genes passed along.

Authoritarian societies were not better in any sense- but their members were more reproductively successful. Even before the military invasions, it’s likely that authoritarians, with their combination of fundamentalist religious belief and unquestioning acceptance of hierarchy were able to outbreed more lackadaisical tribal members. Even today authoritarianism and religion are tightly linked. It is also known that religious people tend to breed more (hence the baby fetishism prominent among Evangelical Christians even today). Once their genes became the majority – these societies were able to militarily conquer everything in their path. The use of religion to ensure tribal cohesion and divide groups into “us and “them – which also continues even today – helped increase the success of such tribes and their gene pool, ensuring that more and more people shared this world view.

The downside is that people were essentially enslaved by their minds – bound to serve and obey no matter what. The kind of bizarre and disordered thinking that characterizes authoritarianism – the belief in leaders so intense as to deny reality – is a genetic feature that seems to have spread through populations over thousands of years, and it is such behavior that makes hierarchical civilization possible. Simply put, authoritarians are more reproductively successful.

These beliefs were probably combined with the cocktail of other beliefs that have come to define civilization – a belief in dominance over nature, a removal or all checks on reproduction and a desire for permanent growth, a worship of military dominance, a desire to win at all costs and see all of society as a competition, a disdain for equality, etc. Again, look to the Bible – man is given dominion over the earth and everything in it. The Epic of Gilgamesh begins with Gilgamesh chopping down the forest to build a city.

From these origins, civilization spread not because people loved the idea. Civilization has always been spread by force. But what has maintained it? When civilized people took over other tribes, they practiced selective breeding to transform the gene pool into a mirror image of their own. This is what made civilization “spread.” Even today “primitive” tribes are wiped out.

Most of us are probably descended from these Semitic tribal peoples. Their authoritarian genes are the glue that holds modern society together even today. And even today people who object to the dominant social order are culled – prevented from reproducing, either through poverty or outright violence. Thus our genes continue to change – continue to get more and more authoritarian.

The other possibility is that modern American society is changing us genetically to be more cruel, selfish and less empathetic. Cultures are shaped by female preference. American woman seem to prefer the smarmy, glad-handling, garrulous, back slapping corporate salesman-type with the elevated mood. Plus, success is increasingly determined by your ability to navigate the Machiavellian world of corporations, meaning such people are able to have more children. Studies have conclusively shown that empathy is significantly declining among college students. And it is also known that empathy is associated with certain brain structures which are likely genetic in origin. is it possible American society, with it's promotion of the most selfish and sociopathic individuals, is breeding out human qualities like empathy and compassion? As an immigrant society, Americans are already self-selected for traits such as optimism, religiosity, greed, etc.

It is not surprising that the social revolutions of the Enlightenment in Europe began after the colonization of the New World. Simply put, the authoritarians were all shipped to the Americas. Most of them self-selected on the basis of religiosity. The populations remaining behind in Europe had a higher percentage of people less accepting and more critical of the social order, allowing revolutionaries to gain a toe-hold and gain enough popular support to topple the social order. That may seem paradoxical considering the American Revolution, but remember that was a top-down revolution led by aristocrats who were not supported by the majority of the population. today we see America devolving into an almost medieval feudal social order ruled by ignorance and superstition, and with more rigid hierarchy and less class mobility than Europe.