A huge research project about DNA (ENCODE) has provoked more scientific controversy over just what proportion of that huge molecule plays an active role in making us us. When DNA research first began decades ago, it was thought that only a couple percent of all those millions of pairs of Adenosine (As) and Thymine (Ts), and Cytosine (Cs) and Guanine (Gs), actually do anything that is biologically relevant to humans. The rest was labeled junk (many scientists winced at the imprecision of the term but when one coined it, it stuck). The new research adds to earlier evidence that as much as 80% of DNA might in fact be ‘functional’. Not so fast, argue some experts, who say that while all those A-T and C-G pairs may be functional, they are not functional in ways that are biologically relevant to us being us. (For a richer discussion of the science, see this by computational biologist Sean Eddy)
The disagreement is partly just the nature of science, where healthy skepticism is supposed to challenge ideas to see if they stand up to careful examination. But some of the response to ENCODE – particularly the resistance to the idea that more of the DNA molecule may be functional in relevant ways for humans than has been previously thought - suggests another phenomenon, something basic to human cognition. The brain tends to comfortably stick with, and defend, the way things are initially framed and have always been assumed to be. Because of the way our minds work, there is a built-in challenge to keeping an objectively open mind. This intellectual inertia has a long history in science, with significant costs.
Since the ancient Indians and Chinese and Greeks the belief was that ‘miasma’, bad or vile air, spread disease. In 1847 Ignaz Semmelweis realized that dirty hands were spreading disease at a Vienna obstetrical hospital and had nurses wash their hands, reducing the death toll (earning him the name “The Savior of Mothers). “It’s Miasma”, maintained mainstream doctors, whose intellectual inertia condemned countless millions to illness and death that could have been avoided with simple sanitary procedures that did not become widespread for decades. (Semmelweis died an embittered drunkard.)
Five years later John Snow pioneered epidemiology when he investigated a cholera outbreak in London and figured out that the people getting sick were drinking from one well…that the germ was apparently water-borne. He took it upon himself to remove (steal) the pump handle, and shut off the outbreak. Yet leading English health officials debunked Snow’s finding and clung to the idea of ‘miasma’. After all, they said, note how bad the Thames smells. It was that ‘Great Stink’ more than Snow’s discovery that water carries germs that finally got London to clean up its drinking water.
In the 1890s Dr. William Halstead, a surgical pioneer of great influence at the time, established radical mastectomy as the gold standard of treatment for breast cancer, and despite early evidence that it did little good compared to less traumatic approaches (basically, none of them worked), oncologists refused to abandon Halstead’s approach as late as the 1970’s (see The Breast Cancer Wars), condemning tens of thousands of women to unnecessary suffering and disfigurement.
Consider how this intellectual version of Newton’s First Law…an object at rest tends to stay at rest (an idea once accepted tends to stay accepted)…bears on some huge current health issues. Despite strong evidence questioning the efficacy of the Prostate Specific Antigen (PSA) test, many urologists still cling to it as the established way to detect prostate cancer, and cling to radical treatments rather than “watchful waiting” even for tumors diagnosed as slow growing, condemning tens of thousands of men to sexual impotence and urinary incontinence who need not suffer those harms
A few scientists (Carlos Sonnenschein and Ana Soto among them) are daring to question the fundamental idea of how cancer starts….the somatic mutation theory that cancer is caused from mutations to the genes that control cell growth. They have found tumors with no evidence of DNA mutation, and offer a different idea about carcinogenesis. Many in the mainstream science community are treating them like Semmelweis and Snow.
A fresh way of doing toxicology - the study of poisons - has found strong evidence to suggest that things that are bad for us at high doses may actually either do no harm or even be good for us at low doses. (In one study that compared rats exposed to low doses of DDT to rats not exposed at all, the rats exposed to low doses of DDT had less liver cancer.) You will not be surprised to learn that Ed Calabrese, the main proponent of this theory, known as hormesis, is getting the Semmelweis/Snow treatment.
Because our brain is constantly called on to make choices and decisions - and rarely has all the facts, or all the time necessary to go get the facts, or all the smarts necessary to understand all the facts, what Herbert Simon called Bounded Rationality – human cognition has developed a wonderful range of mental shortcuts for making these judgments on the fly. One of them is to default to the way things are ‘framed’. The way we learn things, especially if we learn them from ‘the experts’ or other trusted sources, establishes The Way It Is, and we tend to fight back against, to resist, information that conflicts with that initial framing. (Pluto will always be a planet to me.) It would take time, attention, effort - literally calories spent by the brain - to keep a completely open mind and think everything through afresh every time some new evidence comes in.
This resistance to new ideas is particularly acute, of course, among people who have a vested interest in The Way It Is, professionals whose careers and funding, and self-identity, depend on having their view of The Accepted Paradigm prevail. This is especially true, of course, for academics and scientists.
But this innate facet of human cognition, that narrows our thinking and causes us to resist new ideas, puts us at risk. Science is not knowledge. Science is the process of methodically testing ideas to see where the bulk of the evidence lies, and requires the effort of an truly open mind, even when new ideas challenge existing beliefs. The ENCODE DNA (See The Story of You for a wonderful animation about the project) evidence offers rich new details about DNA…as some experts have put it, a ‘Google Street’ level of detail of what we formerly only saw at the detail of ‘Google Earth’. But beyond all the physical things it can teach us, the resistance by some to fresh ideas about DNA should serve as another warning that, in the name of human health, and progress, we need a little more humility about what we claim we ‘know’, and a lot more humility about the innate limits on our capacity to think and reason and establish ‘the truth’ in a purely objective way.