A major source of difficulties in promoting students' understanding of genetics lies in the presentation of gene concepts and models in an inconsistent and largely ahistorical manner, merely amalgamated in hybrid views, as if they constituted linear developments, instead of being built for different purposes and employed in specific contexts. In this paper, we report the results of a study about how textbooks can provide the grounds for the students' construction of such hybrid views about genes. These views are a key problem in genetics teaching, because they make it more difficult that students properly understand this central biological concept and strengthen genetic deterministic ideas, which characterize a widespread discourse about genes in the public opinion. We analyzed 18 textbooks using categorical content analysis, employing categories derived from the literature addressing the historical development of gene models and concepts. Our findings indicate that the analyzed textbooks do convey hybrid views about genes, with no correspondence to scientific models related to this biological concept. These views reinforce genetic deterministic discourses and may lead students to serious misunderstandings about the nature of genes and their role in living systems, with consequences to future learning about genetics.