Question

Below are experimental and control groups for an experiment that is seeking to determine if testosterone has an organizational effect on the production of color in a fence lizard. Critique this experimental design and suggest any changes that might improve the design.

Group 1: Adult male lizards who are castrated

Group 2: Adult male lizards who are castrated implanted with testosterone pellets that release a daily dose of testosterone similar to that in a normal adult male

Group 3: Adult male lizards who received the same surgical procedure as lizards in group 1 except the castration