This study investigated seventh grade learners' decision making about genetic engineering concepts and applications. A social network analyses supported by technology tracked changes in student understanding with a focus on social and conceptual influences. Results indicated that several social and conceptual mechanisms potentially affected how and why ideas were taken up in the learning system of the classroom. Mechanisms included copying or memetic processes such as "do as the smart students do" and friendship selection. Study outcomes are compared with the broader literature on memes and memetic processes to reveal general evolutionary ideas such as the development of prestige, identity versus problem-solving strategies, extended phenotypes, and memeplexes. Educational implications for this research are also addressed. (Contains 2 figures, 5 tables, and 1 note.)