X, the model | Y, the system being modeled | Shared properties between X and Y | Perturbation to the model | Outcome in model | Outcome in system being modeled |
---|---|---|---|---|---|
Animal system (for example, Pan troglodytes) | Human system | Â | Â | Â | Â |
 |  | a. Genes. >90% of nucleotide sequences identical. | Exposure to HIV. | State S1. Mild illness of limited duration. | AIDS. State S1 is not shared despite the presence of shared, relevant properties. |
 |  | b. Immune system. Many commonalities. Constructed on generally the same plan. |  |  |  |
 |  | c. White blood cells present and function similarly. |  |  |  |
 |  | d. Receptors on white blood cells also present and function similarly. |  |  |  |
 |  | e. Shared intracellular components of white blood cells. |  |  |  |