Animal models

Animal models are living organisms—typically mammals, birds, or other vertebrates—used in scientific research to study diseases, test treatments, and understand biological processes relevant to humans or other species. They serve as stand-ins for studying phenomena that would be unethical or impossible to observe directly in people.

The choice of model organism depends on the research question. Mice and rats dominate biomedical research due to their genetic similarity to humans, short lifespans, and established laboratory protocols. Zebrafish excel in studying neural development and gene expression. Fruit flies revolutionized genetics. Non-human primates provide closer behavioral and physiological parallels to humans but raise significant ethical concerns.

Animal models have enabled breakthroughs in understanding cancer, neuroscience, drug development, and immunity. However, they come with limitations: biological variability across species means findings don't always translate to humans. This has driven growing interest in alternatives—cell cultures, organs-on-chips, and computational modeling—that reduce reliance on living creatures while maintaining scientific rigor.

Related

In vivo, In vitro, Preclinical testing, Ethics of animal research, Laboratory animal welfare, Translational medicine