New research shows that a unique strain of laboratory mice characterized at Penn State University has behavioral, hormonal, and neurochemical characteristics that are similar to those of human patients with drug-resistant forms of depression. The mice -- which have a defect in a gene -- are expected to be useful as a new model organism in the effort to develop more effective medications for specific forms of depression.
As I stated in my blog Spinal Cord Regeneration in Mice, genes work in complex systems that are robust. Robustness means that the system is adaptable and has backups, for example one gene can perform more than one function, and thus the system is at least somewhat resistant to change. Genes are also affected by background genes. This, in part, explains why genetically modified mice have been such failures at predicting human response. (See Spinal Cord Regeneration in Mice and Animal Models in Light of Evolution for references.)
So why does this practice continue? The following from Michael Shermer writing in Scientific American is worth considering:
Unfortunately, says Feynman’s Caltech colleague David Goodstein in his new book On Fact and Fraud: Cautionary Tales from the Front Lines of Science (Princeton University Press, 2010), some scientists do try to fool their colleagues, and believing that everyone is conventionally honest may make a person more likely to be duped by deliberate fraud. Nature may be subtle, but she does not intentionally lie. People do. Why some scientists lie is what Goodstein wants to understand. He begins by debunking myths about science such as: “A scientist should never be motivated to do science for personal gain, advancement or other rewards.” “Scientists should always be objective and impartial when gathering data.” “Scientists must never believe dogmatically in an idea or use rhetorical exaggeration in promoting it.” “Scientists should never permit their judgments to be affected by authority.” These and many other maxims just do not reflect how science works in practice.
Knowing that scientists are highly motivated by status and rewards, that they are no more objective than professionals in other fields, that they can dogmatically defend an idea no less vehemently than ideologues and that they can fall sway to the pull of authority allows us to understand that, in Goodstein’s assessment, “injecting falsehoods into the body of science is rarely, if ever, the purpose of those who perpetrate fraud. They almost always believe that they are injecting a truth into the scientific record.” Goodstein should know because his job as the vice provost of Caltech was to investigate allegations of scientific misconduct. From his investigations Goodstein found three risk factors present in nearly all cases of scientific fraud. The perpetrators, he writes, “1. Were under career pressure; 2. Knew, or thought they knew, what the answer to the problem they were considering would turn out to be if they went to all the trouble of doing the work properly; and 3. Were working in a field where individual experiments are not expected to be precisely reproducible.” (Shermer 2010)
Studies on animals are not always precisely reproducible as they vary from lab to lab and from strain to strain and biomedical research scientists are always under career pressure. While the situation Shermer and Goodstein describe above is not identical to scientists using a research modality that is known to be a failure, both from empirical evidence and theoretical concerns, the similarities are, in this case, close enough.
Shermer, Michael. 2010. When Scientists Sin. Scientific American (July):34.