Animal Experimentation - Frequently Asked Questions: Isn't it true that animals are just like people on a cellular level?
An Animal Rights Article from


AFMA Americans for Medical Advancement
March 2006

Isn't it true that animals are just like people on a cellular level?

Whereas all animal cells have properties in common - a nucleus, ribosomes, mitochondira and so forth - we now know that even smaller idiosyncrasies distinguish the way the cells of different species react to food, environment and medications. These idiosyncrasies, visible only through an electron microscope, are both the cause and the result of the evolution that created dissimilar creatures.

Failed animal experimentation has irrevocably proven that tiny differences can prevent or enable disease. White blood cell surface receptors, for example, leave humans vulnerable to AIDS. Among primates, only humans have sialic acid, a glycoprotein molecule on the cell surface. Scientists now suggest that this explains why other primates are so immune to diseases like malaria, prostate cancer, and cholera.

In struggling to learn why animal experimentation does not lead to the same results, scientists are slowly defining the microscopic factors - such as enzymes, glycoproteins receptors, and beta-chemokines - that create variability between human and non-human cells. All cells do not act alike because they are different. And very small differences between humans and animals lead to lethal errors when applying animal data to humans.

Even the book widely regarded as a sort of Bible for animal experimenters, The Handbook of Laboratory Animal Science, states,

It is impossible to give reliable general rules for the validity of extrapolation from one species to another. This... can often only be verified after the first trials in the target species (humans)... Extrapolation from animal models... will always remain a matter of hindsight....

Go on to Animal Experimentation: Frequently Asked Questions: Don't surgeons train on animals before operating on humans?

Return to Animal Rights Articles
Read more at Alternatives to Animal Testing, Experimentation and Dissection