Exploring Two-Year College Biology Instructors' Preferences around Teaching Strategies and Professional Development.

Nearly half of all college students and the majority of college students of color begin their studies at 2-year colleges. The educational quality that these students experience will affect future success, but little research to date has focused on the professional development (PD) of their instructors. We offer an exploratory study on PD needs and preferences of ten 2-year college biology instructors who have experience with evidence-based instructional practices. Using a literature review and interview data, we address four research questions. We contextualize the interview results by describing interviewee teaching styles and their teaching and inclusion strategies, drawing on categorizations from education research literatures in and beyond biology. We then summarize interviewee experiences, preferences, and recommendations for PD. Most interviewees preferred PD that could be readily applied to their courses and included follow-up community support. While our purposive sample is limited, we note high levels of interest in PD supporting inclusive pedagogy and non-biology learning goals, such as study skills, metacognition, and quantitative skills. We describe implications for inclusive design of biology instructor PD.

Group Random Call Can Positively Affect Student In-Class Clicker Discussions.

Understanding how instructional techniques and classroom norms influence in-class student interactions has the potential to positively impact student learning. Many previous studies have shown that students benefit from discussing their ideas with one another in class. In this study of introductory biology students, we explored how using an in-class accountability system might affect the nature of clicker-question discussions. Clicker-question discussions in which student groups were asked to report their ideas voluntarily (volunteer call) were compared with discussions in which student groups were randomly selected to report their ideas (random call). We hypothesized that the higher-accountability condition (random call) would impress upon students the importance of their discussions and thus positively influence how they interacted. Our results suggest that a higher proportion of discussions in the random call condition contained exchanges of reasoning, some forms of questioning, and both on- and off-topic comments compared with discussion in the volunteer call condition. Although group random call does not impact student performance on clicker questions, the positive impact of this instructional approach on exchanges of reasoning and other features suggests it may encourage some types of student interactions that support learning.

Cues Matter: Learning Assistants Influence Introductory Biology Student Interactions during Clicker-Question Discussions.

The cues undergraduate biology instructors provide to students before discussions of clicker questions have previously been shown to influence student discussion. We further explored how student discussions were influenced by interactions with learning assistants (LAs, or peer coaches). We recorded and transcribed 140 clicker-question discussions in an introductory molecular biology course and coded them for features such as the use of reasoning and types of questions asked. Students who did not interact with LAs had discussions that were similar in most ways to students who did interact with LAs. When students interacted with LAs, the only significant changes in their discussions were the use of more questioning and more time spent in discussion. However, when individual LA-student interactions were examined within discussions, different LA prompts were found to generate specific student responses: question prompts promoted student use of reasoning, while students usually stopped their discussions when LAs explained reasons for answers. These results demonstrate that LA prompts directly influence student interactions during in-class discussions. Because clicker discussions can encourage student articulation of reasoning, instructors and LAs should focus on how to effectively implement questioning techniques rather than providing explanations.

Understanding clicker discussions: student reasoning and the impact of instructional cues.

Previous research has shown that undergraduate science students learn from peer discussions of in-class clicker questions. However, the features that characterize such discussions are largely unknown, as are the instructional factors that may lead students into productive discussions. To explore these questions, we recorded and transcribed 83 discussions among groups of students discussing 34 different clicker questions in an upper-level developmental biology class. Discussion transcripts were analyzed for features such as making claims, questioning, and explaining reasoning. In addition, transcripts were categorized by the quality of reasoning students used and for performance features, such as percent correct on initial vote, percent correct on revote, and normalized learning change. We found that the majority of student discussions included exchanges of reasoning that used evidence and that many such exchanges resulted in students achieving the correct answer. Students also had discussions in which ideas were exchanged, but the correct answer not achieved. Importantly, instructor prompts that asked students to use reasoning resulted in significantly more discussions containing reasoning connected to evidence than without such prompts. Overall, these results suggest that these upper-level biology students readily employ reasoning in their discussions and are positively influenced by instructor cues.

bmp2b and bmp4 are dispensable for zebrafish tooth development.

Bone morphogenetic protein (Bmp) signaling has been shown to play important roles in tooth development at virtually all stages from initiation to hard tissue formation. The specific ligands involved in these processes have not been directly tested by loss-of-function experiments, however. We used morpholino antisense oligonucleotides and mutant analysis in the zebrafish to reduce or eliminate the function of bmp2b and bmp4, two ligands known to be expressed in zebrafish teeth and whose mammalian orthologs are thought to play important roles in tooth development. Surprisingly, we found that elimination of function of these two genes singly and in combination did not prevent the formation of mature, attached teeth. The mostly likely explanation for this result is functional redundancy with other Bmp ligands, which may differ between the zebrafish and the mouse.

Conservation and divergence of Bmp2a, Bmp2b, and Bmp4 expression patterns within and between dentitions of teleost fishes.

The diversity of tooth location in teleost fishes provides an excellent system for comparing genetic divergence between teeth in different species (phylogenetic homologs) with divergence between teeth within one species (iterative homologs). We have chosen to examine the expression of three members of the bone morphogenetic protein (Bmp) family because they are known to play multiple roles in tooth development and evolution in tetrapod vertebrates. We characterized expression of Bmp2a, Bmp2b, and Bmp4 during the development of oral and pharyngeal dentitions in three species of teleost fishes, the zebrafish (Danio rerio), Mexican tetra (Astyanax mexicanus), and Japanese medaka (Oryzias latipes). We found that expression in teleosts is generally highly conserved, with minor differences found among both iteratively homologous and phylogenetically homologous teeth. Expression of orthologous genes differs in several ways between the teeth of teleost fishes and those of the mouse, but between these vertebrate groups the summed expression pattern of Bmp genes is highly conserved. Significantly, the toothless oral region of the zebrafish lacks Bmp expression domains found in teleosts with oral teeth, implicating these genes in evolutionary tooth loss. We conclude that Bmp expression has been largely conserved in vertebrate tooth development over evolutionary time, and that loss of Bmp expression is correlated with region-specific loss of the dentition in a major group of fishes.