We hear this all the time in the context of genetics. Over and over and over, we've written about issues that we think are clear, obvious, certainly not secret; problems with genetics that we think explain why we pretty much can't expect to predict phenotype from genotype, or vice versa. Many of the same issues apply to identifying environmental causes of disease. This is the amassed evidence that some defendant (some 'theory' in the case of science) is being wrongly accused (wrongly attributed or applied).
It's more complicated than that, of course. Mendelian genetics had its day, and the cause of many single gene diseases has been identified, but these are largely rare, often congenital conditions, and while these successes are priceless for families with these diseases, the same kind of success hasn't panned out for common, complex diseases. And there are even more seriously troubled waters, if not dangerous rapids, for Mendelian ideas up ahead--as we'll describe in upcoming posts!
The same problems apply to epidemiology -- when infectious diseases were more prevalent in the West, when the field was just coming into its own, infectious agents were readily identified, leading to prevention and cures. Similarly, tobacco was identified long ago as a cause of disease, as was asbestos in buildings, and other chemical toxins.
Our methods work well when the causal agent has a strong effect, that one could see in a dark room while wearing dark glasses. Extensive experimental and observational data show that mutations in the CFTR gene seem to cause cystic fibrosis, inhaling coal dust causes black lung disease. But when multiple genes with small effects, or an interacting network of genes and environmental factors, or a complex diet rather than one component of a single food, or a combination of diet and exercise are the risk factors, identifying cause is harder. Or impossible.
|Courtroom inside Tombstone Courthouse State Historic Park, Photo by Matthew A. Lynn; Wikimedia|
We've blogged a number of times in the last month or so about these issues. About why we think genetics is bogged down with, generally, diminishing returns on ever-larger studies, why its promises of personalized genomic medicine, and the benefits of whole genome sequencing and so on have turned out to be over-promises and won't be attained nearly to their advertised extent.
We're often told that we're too negative. And we're told that if we don't have an alternate model, we should not criticize the status quo. But we believe we've got a positive message, and that is that we've learned a tremendous amount in the last 20 or 30 years about what genes do. The science wouldn't be where it is if we hadn't that knowledge. There's still a lot we don't understand, but we think that at this stage, much of that is because we're constrained in our thinking by a prevailing model that doesn't accommodate all observations. We think new thinking is in order, but, no, we can't personally offer it up. We think about these things all the time, and work with others to explore the issues, but the lesson of history is that the field, or some new young thinker will have to do that.
The positive message is that we have tons of what appears to be reliable knowledge, but knowledge that points to the possibility (or, depending on how you view things, high likelihood) that some very fundamental facts of life are missing, and that current methods are not suited to detect. And the fact that the same sorts of things apply to modern genetics and to evolutionary reconstructions and interpretations, reinforces this: what the current methods can do, and have done, is to show where the confusing, contrary, perplexing, and sometimes paradoxical issues are.
So, it's odd to hear that if we can't produce a new model we should shut up. Or, worse, that by constantly saying these things somebody, like a congressperson, might hear them and wonder if we really need as much money or as many university jobs, as we've been fortunate to have. But maybe such a threat should exist, and clearly! What a stimulus to serious thought!
Imagine a 12 person jury evaluating the evidence on a murder case. Eleven vote to convict, but one juror doesn't, saying that the evidence doesn't add up. She points out the contradictions and the bits of evidence the others have ignored and so on. No, she doesn't know who did commit the murder, but she's convinced the defendant didn't. But the others don't budge. They tell her that if she can't tell them who did do it, they won't change their vote. Hang the accused!
There are problems in genetics....and to press this point is to do a service, not a disservice, to the elusive truth that confronts us. Whether or not anybody cares to listen, we will continue to express our message, fallible as we are, as we see it.
But we're also trying, within our poor powers to add or detract (to paraphrase the Gettysburg Address), to find better ideas.
[This post contributed to equally by both Ken and Anne.]