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Semantics matter

LifeScientist has taken me to task for the last essays so I will respond to his essay here.

In these essays I have said several times that what Dr Shanks and I maintain is that animal models cannot predict human response to drugs and disease. That is what I am writing about. To qualify every sentence with that phrase is not necessary provided the reader is honestly trying to understand the issue and my essays. (I have gone into detail about how animals can be studied to learn about, among other things, conserved processes.)

LifeScientists wrote: “Predicting that a gene may have a particular role is very different from predicting a response to a drug or disease.” This is true. As long as what he means is predicting what the role will be in that species. Shanks and I have said several times that if you want to learn about rats then study rats. Basic research makes no claim to prediction in the way applied research does. That is a fact. To say basic research contains within it prediction about what it is studying is a meaningless tautology.

But even that gets tricky. The role of genes is a good example. Genes that have certain effects in one strain do not have those effects in a different strain (1). So even extrapolation within species may be problematic. Furthermore, men and women do not respond the same to drugs and disease and so forth and there is also variation among ethnic groups, age groups and so forth. So again, one must be careful when using words.

My defintion of predict is the one used in biomedical science as we support in the book.

LifeScientists states:

You're arguing that:

1) Animal researchers use predictivity (as you narrowly define it) as the main argument for animal research

2) Animal models don't predict human responses as well as they should.

3) therefor the sociopolitical basis for funding/permitting animal research is flawed.

Number 1 is correct, although the defintion as I stated it is correct. If LifeScientist disagrees then he needs to produce references backing up the claim. Number 2 is wrong and reveals a misunderstanding about what predict means. There is no such thing as a little predictive otherwise astrology would be predictive. Number 3 is not really correct either. The science influencing the political process is being misrepresented.

LifeScientist states Animal experimenters do not justify their research in such terms. They do. As I said in the last essay, see Animal Models in Light of Evolution (specifically Appendix 3) for more on this.

Life Scientist continues:

Sure there are occasions when we can state that an animal model can be used predict the human response or disease state but more often scientists are clear that their models only partially predict what is going on in humans.

Nope! No such thing as partial prediction. (See previous essay on NPV and PPV.)

LifeScientist continues:

We may state that we can learn from models (animal or otherwise) about a disease or predict (in a hypothesis generation kind of way) what might be happening in a particular biological system in humans, but that is very different to stating boldly that "this is what we see in the model...this is what exactly what we expect to see in humans". You don't even see such claims in newspapers much anymore.

We must be reading very different newspapers. I refer the read to the Foundation for Biomedical Research’s daily email called Total e-Clips for conformation of this (for subscription requests, please e-mail Please subscribe. It is very enlightening.

LifeScientist mentions the role animals have played in HIV research. He again conflates the advance in knowledge in general with knowledge needed for treatments or vaccines. (See the book for more on HIV research and animals.) He continues this theme saying that basic research is directed at developing cures for humans. I again quote Kornberg: “We are urged: Do strategic basic research! Do targeted basic research! How can we make clear the oxymoronic nature of these terms?” Basic researchers must justify their use of animals by promising cures and LifeScientist’s essay is an excellent example of this. There can be no doubt that some basic research will have implications for humans but the probability of this is very contentious. As to LifeScientist’s example of the Human Genome Project being an example of the good that can come from basic research: It was human-based so there should be no surprise that it will benefit humans.


1. Pearson H. Surviving a knockout blow. Nature 2002;415:8-9.


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