On November 4, 2011. Dr Ringach posted a blog titled: Predictions and Animal Models of Human Disease. I will address his issues in this essay.
Dr Ringach: “Some animal activists argue human disease cannot be modeled in animals. They think physiological differences between species imply that treatments developed by means of animal research will not translate to humans.”
The above is not my position. As I have stated many times, the probability that animal-based treatments will translate is very low. This is supported by the scientific literature.(Crowley 2003; also see Greek and Greek 2010) By making the argument appear all-or-none Dr Ringach hopes the reader will commit the fallacy of composition equating a single success with the success of the modality as a whole.
Dr Ringach: “This language delicately nudges one to equate different concepts, namely theory, hypothesis, modality and method. In this deceptively innocuous equation, resulting from either an honest misunderstanding or mischievous intent, lies the foundation to a seriously flawed argument.”
Actually, it is Dr Ringach that confuses hypothesis with theory as I pointed out in the lecture at Toronto and in my abbreviated response to his diatribe in the American Journal of the Medical Sciences. For more on his article see my blog titled Why Debate When You Can Publish Unopposed Nonsense? where you can access his AJMS article. I again suggest everyone read it as there are so many logical and scientific mistakes that it could be used in a class on critical thinking and science. He continues to confuse hypothesis with theory below.
Dr Ringach: “Consider the domain of physics. Here, physicists put forward mathematical theories of some natural phenomenon which, in turn, generate testable predictions. If a prediction is falsified, so is the theory. When this occurs, scientists seek to understand how the data depart from the prediction and use prior knowledge and intuition to develop a new working hypothesis, which is embedded in a new theory. Mathematics is the language of physics — its methodology. Obviously, by using mathematics one can create many different theories. The overwhelming majority of them will be false. Science is difficult because most of the time our ideas turn out to be wrong.”
No. Scientists generate hypotheses that make predictions that can be tested and the hypothesis revised accordingly. A theory is based on a long history of correct predictions, consilience, and a vast amount of evidence. It is no wonder that creationists criticize evolution as just a theory when an NIH grant recipient and UCLA science faculty do exactly the same thing. (I have a publication addressing this exact topic in the review process. If published, it will be open access and I will notify everyone when it is available.)
Dr Ringach goes on to discuss models and most of what he says is correct. But again he commits a fallacy, this time bait and switch. Dr Ringach and I agree that animal models can be used as heuristics. I do not know of anyone that disagrees with this. But while Dr Ringach nicely outlines such a use, he then equates that use with the use of animal models to predict human response to drugs and disease. These are two completely separate uses of animal models. I have gone to great lengths in all the books and article and in most of these blogs to distinguish between areas of science where animal models are valid and areas where they are not. This is simply good scholarship. Conflating such uses is done by people that are purposely trying to confuse the reader or by those who are ignorant of the relevant science.
Dr Ringach: “There is an interesting part of the exchange where Dr. Novella attempts to explain [t]hat some models have indeed been extremely predictive of human response.”
The foundations of a position are important and here again Dr Ringach demonstrates that his lack of knowledge, be it purposely or not, of the foundations of science inhibits his understanding of the issue. As I have stated many times, animals and humans share attributes. It should come as no surprise that for almost every adverse drug reaction, for example, an animal species or strain will eventually be found that reproduces the reaction. This is not the same as saying that the modality of animal models is predictive for human response or that that single species predicted human response. In order for a modality or practice or test to be predictive it must have, among other things, a history of success. One right answer does not make a theory or hypothesis correct nor does it make a paradigm or practice predictive. There are ways these things are calculated in medical science and I have described them in our books and articles and in many blogs (for example, see here and here). To say: “Hypotheses generate predictions” is a very appropriate use of the word. But to say that one correct answer, be it generated from a hypothesis or test or some other practice, means that the hypothesis or test or practice in general is predictive is not scientifically correct. This is not controversial among honest and knowledgeable scientists.
Dr Ringach: “In the eyes of Dr. Greek and the animal rights activists that adhere to his views, the type hard scientific work that leads to the development of a predictive model of human disease boils down to a mere chance discovery.” Once again this is a not what I have said but it is close. Studies have shown that the probability of animal-based basic research leading to new treatments is around 0.004%.(Crowley 2003; also see Greek and Greek 2010.) That is close to what would be expected from mere chance. Moreover, the pharmaceutical community in general has acknowledged that animal models cannot predict human response to drugs. If animal models fail to predict outcomes from drugs one must wonder how vivisection activists explain explain the fact that the Theory of Evolution must have changed in order to allow animal models to predict disease response. It is all the same science.
There is a more general issue here and that is the apathy of the scientific community to correct errors from its own ranks. There are many scientists out there who could correct Dr Ringach on the above issues but they will not speak out. Theory versus hypothesis is not high-level science, neither is the distinction between the use of predictions in hypotheses and the predictive value of a practice or test. However, there is an unfortunate attitude that any criticism of scientists is a criticism of science in general. This is a self-defeating attitude but not one that I think is likely to change. Combine that with the fact that animal-based research funds many university activities and there is a very real disincentive for honest scientists to speak out on this issue. When scientists bemoan the fact that society in general does not accept scientific principles, they need look no further than inconsistencies like this to explain why.
In the final analysis, Dr Ringach was offered the opportunity to debate this issue in the scientific literature. He refused. That pretty much settles the issue for many.
For a fuller explanation of these concepts see:
Crowley, W. F., Jr. 2003. Translation of basic research into useful treatments: how often does it occur? Am J Med 114 (6):503-5.
Greek, R., and J. Greek. 2010. Is the use of sentient animals in basic research justifiable? Philos Ethics Humanit Med 5:14.