Heuristic Is Not Prediction

| by Dr Ray Greek

Vivisection activists frequently commit the fallacy of equivocation in their use of the phrase “animal research.” They begin by pointing out (correctly) that animals can be used as biofactories and a source of spare parts for humans. (I covered this here as well as in numerous books and articles.) The fallacy comes in when they then use the same phrase, “animal research,” to describe a separate area of animal use and subsequently equate the success of the one with the other. Efficacy in one area does not imply efficacy in other areas despite being categorized under the same general heading. Despite the fact that insulin came from pigs and cows, pigs and cows are not predictive for human response to drugs and disease.

The other fallacy present in such conversations with vivisection activists is the false dichotomy: either we do it this way or it cannot not be done. For example, animals are used to produce drugs and vivisection activists cite this as proof that without animals these drugs would not be available. Such is sometimes the case, at least for a while, as when science or society believes it has a solution to a problem, it does not always seek a better solution. For example, insulin from animals resulted in side effects for some patients but science was slow to seek an alternative. Eventually, genetic engineering on bacteria resulted in the production of human insulin, which is well tolerated by diabetics. As was the case with insulin, there are usually other options if someone merely seeks them. Plants and bacteria are being used to produce drugs and algae appear to also be a viable option. Scientists at UCSD have made complex proteins using algae and these proteins could not have been made in bacteria or mammalian cells. The process is also less expensive.(Tran et al. 2012)

Animals can also be used as heuristic devices: to generate new ideas. Scientists are currently studying porcupine's quills in hopes of discovering something that will lead to better needles and adhesives. (Cho et al. 2012) Again, this is not the same as using an animal model to predict human response to drugs and disease.

One reason for the lack of predictive value of animal models is convergent evolution: the same trait being generated by different pathways. Blind mole rats and naked mole rats are both immune to cancer but use different mechanism in order to accomplish this. The blind mole rat causes cell death in abnormally dividing cells by secreting interferon-beta protein. The naked mole rat uses gene p16 to make the cells sensitive to overcrowding, thus stopping cell division when overcrowding is sensed. (Gorbunova et al. 2012) Such differences occur among species but also within species. For example the genetics that allow Tibetans to survive at high altitudes differs from the genetics that allows Ethiopians to do the same.(Alkorta-Aranburu et al. 2012)

Other differences between species invalidate the notion that animal models will be predictive value for human response to drugs and disease. Miller et al (2012) discovered that chimpanzees develop myelination during development much faster than humans do. This may assist in explaining why humans suffer from diseases like schizophrenia while chimpanzees do not. As I have stated, animals can be used for comparative research in order to learn more about evolution, but this does nothing to validate animal models as predictive modalities.

The inability of society to use critical thinking in order to discover the fallacies routinely committed by vivisection activists, together with the capitulation of Congress to the lobbyists that represent animal modelers and others, results in real harm to humans.


Alkorta-Aranburu, G., C. M. Beall, D. B. Witonsky, A. Gebremedhin, J. K. Pritchard, and A. Di Rienzo. 2012. The genetic architecture of adaptations to high altitude in ethiopia. PLoS genetics 8 (12):e1003110.

Cho et al. 2012. Microstructured barbs on the North American porcupine quill enable easy tissue penetration and difficult removal. Proceedings of the National Academy of Sciences of the United States of America.

Gorbunova, V., C. Hine, X. Tian, J. Ablaeva, A. V. Gudkov, E. Nevo, and A. Seluanov. 2012. Cancer resistance in the blind mole rat is mediated by concerted necrotic cell death mechanism. Proceedings of the National Academy of Sciences of the United States of America.

Miller et al. 2012. Prolonged myelination in human neocortical evolution. Proceedings of the National Academy of Sciences.

Tran et al. 2012. Production of unique immunotoxin cancer therapeutics in algal chloroplasts. Proceedings of the National Academy of Sciences.