Abstract Mitigating abrupt surface changes that can impede forward progression and stability during locomotion can be critical for survival. Joint-level mechanisms that contribute to dynamic stability under such conditions are still not thoroughly understood. This study examined how kangaroo rats Dipodomys deserti accommodate a decelerating perturbation – a sudden 10-degree upslope. We hypothesized that (1) hindlimb orientation mediates center of mass (CoM) pitch stability and (2) the ankle joint is the primary contributor to increased energy absorption demands caused by the decelerating perturbation. High-speed video and ground reaction forces (GRFs) were recorded as six desert kangaroo rats hopped at steady speed on our variable terrain rotatory treadmill instrumented with the perturbation. An inverse dynamics analysis was used to quantify whole-body and joint-level mechanical output during level and perturbed hopping conditions. Across both conditions, the average hindlimb angle was more retracted as the average orientation of the GRF vector became more accelerative. When acceleration was held constant however, the perturbed condition exhibited a more protracted hindlimb angle than level trials, likely due to anticipation by the animal exhibited through increased hindlimb protraction during the preceding aerial phase to set landing conditions. Analysis of angular impulse about the CoM revealed that the inclusion of the average hindlimb angle in the statistical model produced a positive relationship with both acceleration and condition. This result supports our first hypothesis indicating that the control and modulation of hindlimb orientation mediates pitch stability when animals encounter both challenges in acceleration and the additional decelerative forces associated with the perturbation. At the joint level, net work increased with acceleration at all joints except the metatarsophalangeal joint. Knee work increased at the fastest rate, followed by the ankle. Therefore, our second hypothesis was not supported, most likely due to the inclusion of the tarsometatarsal joint in the inverse dynamics analysis. Due to the upsloped nature of our perturbation, variation in vertical CoM momentum was observed and was modulated through decreased energy absorption at the ankle in the decelerative phase of stance during the perturbed condition. Consistent with prior work from our lab, these results highlight the ankle’s important functional role in the modulation of vertical CoM momentum.
Abstract In an era where networks of connection continue to expand while the depth and quality of those connections seemingly diminish, field-based learning offers a setting uniquely suited to support more meaningful connections. This piece synthesizes the perspectives of biology education researchers who convened at the 2025 Ecological Society of America Conference for an Organized Oral Session entitled “Inclusive teaching practices for more equitable field-based learning.” As a product of that session and the discussion it generated, we center connection as a design aim, one that links the pedagogical choices instructors make to the experiences students have in the field and beyond. We present a series of guiding pedagogical principles crafted to cultivate connection across three interrelated areas: students’ connection to people and culture, connection to place and the natural world, and connection to self (one’s identity and one’s relationship to learning). These pedagogical principles are informed by the primary, secondary, and higher (K-16) educational assessment research presented at the session, the authors' experiences designing, teaching, and evaluating field learning experiences, and relevant discipline-based education research. We argue for the importance of designing inclusive field learning experiences with the intention to foster these types of connections as a means to support student engagement, success, and learning in the field.
Synopsis The ability to use data and evidence as the basis for scientific argumentation is a critical skill that undergraduate students must learn to successfully transition into science careers. There is a need for pedagogical tools that promote the development of science process skills and reduce barriers to implementation in the classroom. PubNavigator (www.pubnavigator.com) is a science communication platform that shares the findings of primary literature using accessible language. Articles on the platform represent a novel form of Adapted Primary Literature accessible to novice learners. We developed a PubNavigator reading assignment that can be easily integrated into introductory-level curricula with minimal time investment from instructors. We implemented this lesson in an introductory biology laboratory and analyzed responses to an assignment prompting discussion of PubNavigator articles in an asynchronous online forum. We conducted content analysis guided by the Toulmin’s Argument Pattern to identify evidence of science argumentation and interactive engagement. PubNavigator assignments prompted students to use evidence as the basis for science arguments, evaluate experimental design, describe the purpose and relevance of scientific research, and prompted overall student engagement. Our assessment data support PubNavigator as an undergraduate teaching tool that can be used to promote science argumentation and engagement in introductory biology. We provide recommendations for implementation and possible adaptations for alternative settings and modalities.
Synopsis Recent calls have urged educators to involve students in the process of science to better engage them in learning. In this study, we investigate the effectiveness of using natural history collections (NHCs), a resource with which most students are unfamiliar, as tools for enhancing undergraduate teaching and shaping student attitudes toward both scientific resources and environmental issues. An inquiry-based module centered on firefly specimen data was implemented in introductory non-majors biology courses. The module aimed to (1) increase students’ perceived value of NHCs, and (2) improve pro-environmental attitudes as measured by the Revised New Ecological Paradigm (R-NEP) scale, and (3) increase student concern regarding firefly conservation. Students engaged with real specimen data to explore historical and current firefly distributions in Utah and evaluate the impacts of human activity, such as light pollution. Pre- and post-assessments revealed significant increases in student awareness of and attitudes toward the value of NHCs. However, improvements in environmental attitudes were limited, with modest gains in R-NEP items related to ecological concern. Additionally, students ranked fireflies lower in conservation priority compared to more charismatic or ecologically familiar organisms such as pandas and moss. These findings suggest that while NHC-based modules were associated with increased reported appreciation for collections as scientific resources, they may require more refinement to produce more meaningful changes in environmental attitudes. Importantly, the study highlights the pedagogical potential for NHC data for active engagement in the classroom.
Abstract The Weberian apparatus is an innovation serving as the primary sound-conduction path for otophysan fishes. In this study, we investigate how North American catfishes (Ictaluridae) how this system varies across diverse ecological landscapes. By leveraging CT scanning and geometric morphometrics on 136 specimens across 47 species, we mapped the evolutionary trajectories of three critical components: the scaphium, tripus, and peripheral structures including the associated vertebrae and ligament insertions. Our findings challenge conventional expectations that the apparatus is phylogenetically conserved. While phylogenetic signal is significant but low, we discovered exceptionally high morphological disparity driven by ecological selective forces. Factors such as stream velocity, climate, and even body coloration correlate strongly with ossicle shape, reflecting functional adaptations to specific micro-habitats. Crucially, we identified a clear signal of modularity; the scaphium and tripus demonstrate decoupled evolutionary rates, allowing them to evolve independently. This modularity suggests that the Weberian apparatus is not a rigid unit, but a highly plastic system that ictalurids might be used to fine-tune their sensory systems to adapt to ecological pressures.
