Choosing which animal species to use in research involves ethical trade-offs based on sentience, similarity to human biology, and the availability of alternatives. Better frameworks for species selection can reduce suffering.
Species selection in research is an ethical decision with major welfare implications. Using a more sentient species when a less sentient one would provide equivalent scientific information is an avoidable harm. However, species selection frameworks are often poorly developed and inconsistently applied. Researchers may default to familiar model organisms without adequately considering whether alternatives would serve the scientific purpose. Developing clearer guidelines for when species substitution is appropriate — and providing training and incentive structures to encourage it — could reduce the use of higher-sentience animals. The expansion of legal protection to invertebrates like cephalopods reflects growing recognition that these decisions must be made on evidence rather than tradition.