Did Scripture Change Human DNA?
It may seem like I’m obsessed by the new Karen Armstrong book, The Case for God (the subject of my last post), but when I innocently clicked on a link at Arts & Letters Daily I didn’t know it would take me to a double review by Jack Miles in the L.A. Times of the Armstrong book and Robert Wright’s The Evolution of God.
As Miles begins his review he cites a recent book by Nicholas Wade about human evolution, including the process of domestication or “taming” of homo sapiens thousands of years ago. In the evolutionary chicken or egg game it’s hard to say what causes what, right? So here is the paragraph by Miles that caught my eye:
Perhaps the “Epic of Gilgamesh” crystallized memories of the long human self-domestication that Wade writes of, but of equal interest is the possibility that rather than merely recalling the change, this and kindred myths may have contributed to it. If such a literary work were recited repeatedly, honored as supreme truth, taught to the young and this over centuries of time — if, in short, it were turned into sacred scripture, then could it not create social pressure, then behavioral changes and, finally, over a sufficiently lengthy period, even genetic modification?
As a literary guy, you know I have to love this.
By the way, when he gets to Armstrong, he strongly endorses her valorization of apophatic theology (the more mystical approach that tends to emphasize what God is not because it is impossible for us to grasp what God is) over the more rational, cataphatic approach to theology.
Von Balthasar and other Ressourcement theologians on the twentieth century made a similar point — that the poetry and mysticism of apophatic theology departs from the West in the late Middle Ages, to the detriment of Church and society.
But I think they would have embraced a Both/And approach rather than an Either/Or approach.Reason at its best understands its limitations.
The appeal of apophatic theology is intense — it’s why some of my Protestant friends are becoming Orthodox. But I want my cake and simultaneously like to wolf it down.
OK, I’ll stop here while I’m in way over my head on scripture, DNA, and apophatic vs. cataphatic theology.
I just find those subjects much, much easier than Afghanistan and health care. I guess I embrace an apophatic politics: I can say what things are not politically good better than I can say what things are….
E. O. Wilson has written a lot about this concept. It is called gene-culture coevolution. Here’s my layman’s understanding of the concept:
Evolution occurs through the interplay of random genetic mutations with changing environmental factors. A sudden (or even slow) change in the environment in which an organism lives can shift which genetic traits help or hurt the organism’s chances of passing on its genes. For example, imagine a species of animals in which there is a genetic subset with an especially think coat of fur. An environmental event that caused an increase in the average temperature where this species lived would hurt the chances of this particular genetic trait from being passed on. On the other hand, an environmental event that caused a decrease in temperature would improve the chances of the genetic trait becoming more widespread in the species.
Now, for humans, our cultural forms very much affect our daily life environment. In hunter-gatherer societies Attention Deficit Disorder may have been a beneficial trait because it would have allowed humans to be more attentitive to sensory information that could help one catch a meal or avoid danger. But in a modern environment where long periods of focused attention to the written or spoken word is an eductional (and so also and economic) advantage, ADD is considered a maladaptice trait.
As religion impacts the shape of our culture, so too will it effect which genes have a higher/lower advantage of being passed on. But this is a two-way street (hence the CO-evolution): our genetic code determines to a great extent which cultural forms have a greater or lesser chance of enduring. (For instance, our instinctive selfish tendencies make it unlikely that large scale systems of communal ownership will last long on the cultural level.)
I think the whole topic is fascinating to think about, but I find that Wilson and many others in the field of sociobiology tend to use the theory in a reductionistic and deterministic way. Wilson contends that religion is in fact nothing more than an adaptive trait that has been preserved because it helps us pass on our genes.
David–
I’ve heard Wilson talk about sociobiology on TV, and I’ve read some of his writing on the subject, but I’m still have my doubts about the scientific bona fides of sociobiology.
For example, in your hunter-gatherer ADD example, which I’m assuming you drew from Wilson, I think we would need much more information, likely not readily available, before we could conclude that ADD had or has a sociobiological impact. There is a general consensus among researchers I think that the majority of instances of ADD (and ADHD) in the general population today have a genetic component. Research has focused I believe on genetic defects in the production of neurotransmitters such as dopamine, However, there are cases of ADD and ADHD where a genetic defect cannot be pinpointed, and scientists think that environmental factors such as diet, exposure to lead, and prenatal exposure to alcohol or tobacco smoke may be the cause of the disorder. Many scientists also think that the disorders may result from a combination of genetic and environmental factors. It seems there may be a very complicated etiology for these disorders.
Let’s assume, however, that ADD is 100% the result of genetic defect. Before we can know if ADD provided an adaptive advantage in hunter-gatherer societies, we would have to know what the incidence of ADD was in that society–was it 1%, 10%, 70%, etc.? Equally important, we’d also have to know what degree of competitive advantage, if any, ADD afforded hunters with the “disorder”. Were large numbers of non-ADD hunters dying out because ADD hunters were markedly more adept at capturing prey and better at not becoming prey? Unless there was some distinct advantage to being an ADD hunter, such that ADD hunters thrived while non-ADD hunters died out, then the genetic transmittal of the ADD defect would not have had an appreciable effect on human evolution. The picture is no doubt more subtle and complicated than I’ve set forth, but, at a minimum, I’m unaware of any empirical information about ADD in the hunter-gatherer epoch that could lead one to conclude that it provided a sociobiological advantage.
On the issue of Scripture possibly altering our DNA, I think that’s far-fetched. Our evolving genotype has certainly resulted in the increase in our capacity to reason, but I think it’s a stretch to say that Scripture or any other non-genetic, non-environmental factor can alter our DNA. We share approximately 96% of our genotype with our cousins the apes, but it is in that 4% genetic variance where our capacities for speech, reasoning, and a host of other abilities unique to humans are found. I could be wrong, but I don’t think there’s any empirical data that supports genetic mutations as a result of devouring literature (unless someone literally ate the printed page itself).
There are several threads that need to be untangled in this question, since writing and religion have effects that may be different from a particular written religious text.
Has writing changed our DNA? Almost certainly, since it has enabled rapid communication and so dissemination of information that affects survival. Have you gotten a flu shot yet? This alters who is most fit by eliminating the need to adapt to many physical influences.
Has religion changed our DNA? Seems likely, since most religions counsel countering nature’s efforts to eradicate the ‘unfit’. Then there is the missionary impulse that is so strong in Christianity and Islam, and has led to intermingling of people from around the world, fashioning varieties of DNA that otherwise would not exist today, eg Korean Scotsmen.
Has any particular scripture changed DNA? I would think Confucius is the most likely, followed by the Bible and the Koran. Hindu scripture might fit in there somewhere, while Buddhist have traveled more widely than the Hindu, making Buddhists more fit than Hindus maybe.. Something like the story of Isaac may have discouraged the sacrifice of children, which may have an impact on who survived, and so on who is fit. (If you are a descendant of Isaac, and have, in your ‘old age’ of 40, a child with Down’s syndrome, would you be as likely to abandon him if you were not Isaac’s descendant? something similar may happen transmittal of genetic defects; I mention Down’s only as something more likely in older individuals.)
The ADD example actually wasn’t from Wilson. It was simply meant as a hypothetical example to show how a single trait could be beneficial in one cultural setting and not in another. There are probably better examples. Basically the point is that culture is an environmental factor that shapes the rate at which specific genes are or are not passed on.
I’m actually skeptical about the bible shaping human genetic development too, but mainly for the reason that the bible has not been around long enough to have had a significant impact. Except in situations of extreme environmental stress evolution happens very slowly. 3,000 years isn’t nearly long enough to make a big difference.
What I find most intriguing about Wilson’s ideas is his contention that our genetic make-up and even many of our cultural forms are carry-overs from the 98% of human history that was spent in hunter-gatherer societies, and that this gentetic legacy has given us instincts and inclinations that are not well suited to our present circumstances. Our tribal nature, our short-term thinking, our strong proclivity for reproduction, and other such traits were aids to survival in our hunter-gatherer past, but they are a threat to our continued existence in our globalized, industruliazed and nuclearized present. I find some aspects of this argument undenialble, but I get very leary when I hear him suggesting that we ought to use our knowledge of evolutionary biology to try to take control of human nature rather than waiting for the long cycle of evolution to weed out these bad traits.
Wow. I am so grateful for these incredibly thoughtful, provocative reflections. Wish I knew enough to fully participate in this conversation but I’m learning a lot. Thanks.
“Has writing changed our DNA? Almost certainly, since it has enabled rapid communication and so dissemination of information that affects survival. Have you gotten a flu shot yet? This alters who is most fit by eliminating the need to adapt to many physical influences.”
I have to respectfully disagree with Jim on this. I admit to not being well-versed in sociobiology, but the (former) biology teacher in me can’t resist what I hope is a well-meaning synopsis of natural selection. Perhaps the best way to explain it is to raise the “short-neck giraffe/long-neck giraffe” example often used in biology classes to explain why we have long-necked giraffes today. Let’s assume that 100,000 years ago there were short-necked giraffes living on the African savannah, and that they ate exclusively the leaves and fruits on a particular species of tree (X) that was within their reach. Let’s also assume that tree X had a variant (Y) a few feet taller than X with fruits and leaves the short-necked giraffes would also have found delectable if only they could have reached them. An environmental change occurs that begins to kill off the X trees over a 10-year period, but the Y trees are left unharmed. As more and more of the X trees wither and die, the competition for the dwindling food source becomes more and more intense.
Jean-Baptiste Lamarck posited an evolutionary theory for long-necked giraffes that was very popular in the early nineteenth century. His theory became known as “soft inheritance.” According to Lamarck, a significant number of the short-necked giraffes would turn to the Y trees for food as the X trees became scarcer and scarcer. The giraffes would strain to reach higher and higher to such a degree that they would actually stretch their necks to a point where they could reach the low-hanging leaves and fruit on the Y trees. Lamarck believed that the giraffes’ necks would actually become physically elongated and that this acquired trait could be passed to successive generations. Put another way, Lamarck believed that evolutionary adaptation is driven by an organism’s survival efforts during his or her lifetime.
Darwin comes along in the late nineteenth century with his theory of natural selection, and he shows convincingly that giraffes today are long-necked because (1) purely by chance (that’s the key), there must have been at least a few mutant (i.e., long-necked) giraffes in existence at the time the environmental change starting killing off X trees, or (2) purely by chance, at least a few mutant giraffes were born during the die off. For Darwin (and I think he’s right), evolution is a very cold-blooded and dispassionate process. If there hadn’t been any mutant giraffes in existence when all of the short-necked giraffes had died off, then giraffes would have become extinct. There have been countless species over evolutionary history (even well before homo sapiens acquired the ability to drastically alter the web of life over the last 500 years or so) that have disappeared because there were no variants among their members that could withstand a deadly environmental stressor.
Darwin didn’t know the molecular details underlying mutations, but he knew enough to know that the mutations that guaranteed a specie’s survival had to have become embedded in the sex cells of the plant or animal species so that they could be transmitted to future generations. Today we know that mutations are biochemical alterations in an organism’s DNA, and that many are not in fact beneficial (e.g., Down’s Syndrome, sickle cell anemia, Kleinfelter’s Syndrome).
Jim mentions flu shots as altering who is most fit by eliminating the need to adapt to many physical influences. I think that is very Lamarckian. :) A flu shot can certainly be very beneficial to the individual who receives it, but unless that shot produces a mutation–a biochemical change– in the structure of an individual’s DNA that will be beneficial to survival, then the benefit of that flu shot to the individual will not be passed on the individual’s offspring. Flu shots don’t work that way; the vaccine does cause biochemical change in the body, but the change involves enhancement of the recipient’s immunological system. While it’s true a flu shot may save an individual from death and allow him or her to reproduce, the molecular benefit to that person is not the kind of adaptive change that gets passed on to a person’s future offspring. Evolutionary adaptation, by contrast, involves biochemical change that is trans-generational.
(Apologies for the length…)
This reminds me of of Neal Stephenson’s Snow Crash. In short, Enki (a Mesopotamian priest) endows all humanity with consciousness using a kind of linguistic virus. Prior to this, only rare, genetically fortunate individuals possessed true self-awareness. It’s science fiction, of course, but I couldn’t help noticing a passing resemblance.
William, the disagreement may be in what we mean by change. To continue your analogy, insulating from the environment means that both short necked and long necked giraffes would continue to exist. Something comparable happens with a flu vaccine, which prevents elimination of those most susceptible to the flu. The evolutionary process is interrupted, meaning the genome stays the same rather than changing in response to environmental stresses. I never meant to suggest that short necked giraffes somehow gained long necks, only that both short and long necked giraffes would continue to thrive despite environmental changes.
This change from a dynamic evolutionary process, to a static, unchanging population is not a “change in DNA” exactly. But it will have an effect ultimately on what our DNA is. Given enough time of course, which has not been the case thus far for cultural influences.
Jim–
Thanks for your response. I see your point now. With scientists on the verge (i.e., over the next couple od decades) of developing clinical treatments (e.g., replacement gene therapy) derived from the manipulation of the building blocks of life, there could be significant impact on the human genome. I think humanity will be at a crossroads in the not too distant future. Repairing genetic defects at the molecular level will of course be beneficial to the afflicted, but as scientists become more proficient at, and, even more worrisome, more comfortable with, tinkering with the essential stuff of life, who knows what biological Lego creations may be in store (e.g., designer children, animal-human hybrids)? The implications for the human genome could be far-reaching. At a minimum, bioethicists will very likely have job security, and they hopefully will become society’s canaries-in-the-mine regarding the ethical ramifications of the genetic breakthroughs that are just over the horizon.
As I understand Darwin, evolution is shot through with randomness, andas Biil points out, to assume that any particular mutation is a change for the better is unwarranted. A mutation benefits a species only if it allows the species to adapt to the de facto environment. pHowever, environments themselves sometimes change rapidly, and are thus themselves in effect randomly related to any given species. To assume that ADD has been determined by biological forces to some benign biological end is thus unwarranted. In fact, this is the sort of reasoning the creationists do: they assume that biological processes have been directed to this superior species, man.
If our “way of thinking” can be affected by dramatic influences then perhaps scripture could have a lasting effect. Even if this was the case though, would people be sufficiently affected by scriptures and how would those changes be preserved? Some reincarnationists profess evolution of the “soul”. If anything, it would seem that this would be the most logical candidate.
D J Wray
http://www.atotalawareness.com
“Everything has now changed except for our way of thinking. ” – Albert Einstein