The oral arguments of 12th grade students while solving tasks related to evolution are examined. Two groups (N = 45), taught by the same teacher, were studied during a complete teaching sequence. The paper focuses on data from the last sessions, devoted to solving problems in small groups, problems related to different dimensions of the evolutionary model. Data include video recordings, the students' written productions and the researcher (first author) field notes. The objective is to examine the process of articulation of students' argumentation practices with their use of evolutionary models. The results show that participants were able to apply notions such as common ancestors, radiation, or gradualism to different contexts. The arguments required the articulation of evolution notions with argumentative practices as coordinating evidence with claims at different epistemic levels. The influence of the teacher's strategies in the students' role is discussed.