In this episode of the Behaviorist Book Club podcast, host Matt Harrington delves into a 2023 article by Hagopian and colleagues on applying the evolutionary theory of behavioral dynamics to severe challenging behavior. The discussion begins with an introduction to natural selection and its relation to behavior analysis, emphasizing the importance of both phylogeny and ontogeny. The focus then shifts to the main topic of building artificial organisms through computer codes based on behavior analysis principles to simulate thousands of experiments on behavior change. This concept is illustrated through three simulated studies: functional analysis, functional communication training plus fading, and competing stimulus assessment, showing high matching results between artificial organisms and real clinical scenarios. The episode concludes with reflections on the potential future applications of such artificial organisms in developing new technologies and improving clinical practice, alongside encouragement for listeners to engage with the content and join the ABA Cafe Facebook group for further discussion.   Show notes, links to article, and transcript are available at https://www.behavioristbookclub.com/blog