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To test the hypothesis that students who complete remote online tests experience an ‘online grade penalty’, we compared performance outcomes of second-year students who elected to complete exams online to those who completed face-to-face, paper-based tests in an organic chemistry course. We pursued the following research questions: (RQ1) Are there performance gaps between students who elect to take online tests and those who take face-to-face tests? (RQ2) Do these two groups differ with respect to other affective or incoming performance attributes? How do these attributes relate to performance overall? (RQ3) How does performance differ between students who reported equal in-class engagement but selected different testing modes? (RQ4) Why do students prefer one testing mode over the other? We found that students who elected to take online tests consistently underperformed relative to those who took face-to-face tests. While we observed no difference between the two student groups with respect to their intrinsic goal orientation and incoming academic preparation, students who preferred face-to-face tests perceived chemistry as more valuable than students who preferred to complete exams online. We observed a positive correlation between performance outcomes and all affective factors. Among students who reported similar levels of in-class engagement, online testers underperformed relative to face-to-face testers. Open-ended responses revealed online testers were avoiding exposure to illness/COVID-19 and preferred the convenience of staying at home; the most common responses from face-to-face testers included the ability to perform and focus better in the classroom, and increased comfort or decreased stress they perceived while taking exams.

Students' perceptions of challenges in biology influence performance outcomes, experiences, and persistence in science. Identifying sources of student struggle can assist efforts to support students as they overcome challenges in their undergraduate educations. In this study, we characterized student experiences of struggle by 1) quantifying which external factors relate to perceptions of encountering and overcoming struggle in introductory biology and 2) identifying factors to which students attribute their struggle in biology. We found a significant effect of Course, Instructor, and Incoming Preparation on student struggle, in which students with lower Incoming Preparation were more likely to report struggle and the inability to overcome struggle. We also observed significant differences in performance outcomes between students who did and did not encounter struggle and between students who did and did not overcome their struggle. Using inductive coding, we categorized student responses outlining causes of struggle, and using axial coding, we further categorized these as internally or externally attributed factors. External sources (i.e., Prior Biology, COVID-19, External Resources, Classroom Factors) were more commonly cited as the reason(s) students did or did not struggle. We conclude with recommendations for instructors, highlighting equitable teaching strategies and practices.

Science textbooks communicate fundamental discoveries and serve as platforms showcasing role models for students. However, the scientists represented across undergraduate textbooks do not reflect the demographic makeup of the student population reading those materials. We recommend a series of changes within curricula to challenge the stereotypical identity of science.

The insulin and insulin-like signaling (IIS) network regulates cellular processes including pre- and postnatal growth, cellular development, wound healing, reproduction, and longevity. Despite their importance in the physiology of vertebrates, the study of the specific functions of the top regulators of the IIS network, insulin-like growth factors (IGFs) and IGF binding proteins (IGFBPs), has been mostly limited to a few model organisms. To expand our understanding of this network, we performed quantitative gene expression of IGF hormones in liver and qualitative expression of IGFBPs across tissues and developmental stages in a model reptile, the brown anole lizard ( Anolis sagrei). We found that lizards express IGF2 across all life stages (preoviposition embryos to adulthood) and at a higher level than IGF1, which is opposite to patterns seen in laboratory rodents but similar to those seen in humans and other vertebrate models. IGFBP expression was ubiquitous across tissues (brain, gonad, heart, liver, skeletal muscle, tail, and regenerating tail) in adults, apart from IGFBP5, which was variable. These findings provide an essential foundation for further developing the anole lizard as a physiological and biomedical reptile model, as well as expanding our understanding of the function of the IIS network across species.

While science has profound social impacts, we often teach biology as removed from societally debated issues. Here, we address this gap in biology education through the implementation of novel materials that promote ideological awareness (IA). Using mixed-method analyses, we explore students’ perceptions of the relationship between science and society, as well as their attitudes toward and knowledge of IA in biology. We found students that received the IA curriculum reported relationships between science and society that aligned with the IA activities, such as providing solutions to societal problems and combating misinformation. Additionally, we discovered a preference for IA materials over a traditional curriculum, with persons excluded because of their ethnicity and race (PEERs) reporting greater approval than non-PEERs. Although we found that the IA curriculum did not result in significant gains in science identity, engagement in biology, or science community values, we did find that students gained awareness of IA topics through a task in which they named as many scientists as possible. Specifically, IA students displayed a 300% increase in the frequency of named scientists from minoritized backgrounds compared with the traditionally taught students. We encourage instructors to incorporate IA materials into their curricula as we move toward more diverse, equitable, and inclusive teaching practices.

Locomotor performance is a key predictor of fitness in many animal species. As such, locomotion integrates the output of a number of morphological, physiological, and molecular levels of organization, yet relatively little is known regarding the major molecular pathways that bolster locomotor performance. One potentially relevant pathway is the insulin and insulin-like signaling (IIS) network, a significant regulator of physiological processes such as reproduction, growth, and metabolism. Two primary hormones of this network, insulin-like growth factor 1 (IGF1) and insulin-like growth factor 2 (IGF2) are important mediators of these processes and, consequently, of life-history strategies. We sprint-trained green anole (Anolis carolinensis) females to test the responsiveness of IGF1 and IGF2 hepatic gene expression to exercise training. We also tested how sprint training would affect glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and eukaryotic elongation factor 2 (EEF2). The former is a crucial enzyme for glycolytic function in a cell, and the latter is necessary for protein synthesis. Resistance exercise forces animals to increase investment of resources towards skeletal muscle growth. Because IGF1 and IGF2 are important hormones for growth, and GAPDH and EEF2 are crucial for proper cellular function, we hypothesized that these four genes would be affected by sprint training. We found that sprint training affects IGF and EEF2 expression, such that larger sprint-trained lizards express hepatic IGF1, IGF2, and EEF2 to a lesser extent than similarly sized untrained lizards. These results demonstrate that the IIS, and pathways connected to it, can react in a size-dependent manner and are implicated in the exercise response in reptiles.

The insulin and insulin-like signaling (IIS) network is an important mediator of cellular growth and metabolism in animals, and is sensitive to environmental conditions such as temperature and resource availability. The two main hormones of the IIS network, insulin-like growth factor 1 (IGF1) and insulin-like growth factor 2 (IGF2), are present in all vertebrates, yet little is known regarding the responsiveness of IGF2 in particular to external stimuli in non-mammalian animals. We manipulated diet (low or high quantity of food: low and high diet group, respectively) in adult green anole (Anolis carolinensis) females to test the effect of energetic state on hepatic gene expression of IGF1 and IGF2. The absolute expression of IGF2 in female green anoles was 100 times higher than that of IGF1 regardless of diet treatment, and IGF1 and IGF2 expression interacted with post-treatment body mass and treatment, as did the expression of the purported housekeeping genes glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and eukaryotic elongation factor 2 (EEF2). The low diet group showed a negative relationship between body mass and gene expression for all genes, whereas the relationships between body mass and gene expression in the high diet group were either absent (in the case of IGF1) or positive (for all other genes). After accounting for total change in mass, the low diet group expressed IGF2, GAPDH and EEF2 at higher levels compared with individuals in the high diet group of a similar change in mass. These results illustrate that expression of IGF1 and IGF2, and of the housekeeping genes is affected by energe­tic status in reptiles.

Tradeoffs between life-history traits are due to limited resources or constraints in the regulation of genetic and physiological networks. Tail autotomy, with subsequent regeneration, is a common anti-predation mechanism in lizards and is predicted to trade off with life-history traits, such as reproduction. We utilize the brown anole lizard with its unusual reproductive pattern, of single-egg clutches every 7–10 days, to test for a tradeoff in reproductive investment over eight weeks of tail regeneration on a limited diet. In contrast to predictions, we found that investing in tissue regeneration had a positive effect on reproduction in terms of egg size (11.7% relative to controls) and hatchling size (11.5% relative to controls), and no effect on egg number or survival, with the increase in reproduction starting at peak regeneration. We discuss mechanistic hypotheses that the process of regeneration may cause increased energetic efficiency or utilized shared physiological pathways with reproductive investment.

Synopsis Early exposure to course-based undergraduate research experiences (CUREs) in introductory biology courses can promote positive student outcomes such as increased confidence, critical thinking, and views of applicability in lower-level courses, but it is unknown if these same impacts are achieved by upper-level courses. Upper-level courses differ from introductory courses in several ways, and one difference that could impact these positive student outcomes is the importance of balancing structure with independence in upper-level CUREs where students typically have more autonomy and greater complexity in their research projects. Here we compare and discuss two formats of upper-level biology CUREs (Guided and Autonomous) that vary along a continuum between structure and independence. We share our experiences teaching an upper-level CURE in two different formats and contrast those formats through student reported perceptions of confidence, professional applicability, and CURE format. Results indicate that the Guided Format (i.e., a more even balance between structure and independence) led to more positive impacts on student outcomes than the Autonomous Format (less structure and increased independence). We review the benefits and drawbacks of each approach while considering the unique elements of upper-level courses relative to lower-level courses. We conclude with a discussion of how implementing structured skill-building can assist instructors in adapting CUREs to their courses.

The coronavirus disease (COVID‐19) outbreak forced an emergency transition to online classes across the world with little warning or instruction for faculty and students. The goal of this research was to document how this response impacted undergraduate students studying the principles of evolution in an introductory organismal biology class over time; specifically, how their study habits for exams differed (a) one week and (b) one month after a university's decision to transition to emergency remote instruction. We asked students about the extent to which COVID‐19 impacted their study habits, and we categorized students’ responses using open coding. We identified a number of consistent similarities—as well as dramatic differences—in their responses as the time away from campus increased. The report that follows is a summary of the documented barriers and recommendations based on literature concerning crises and equitable practices., The goal of this research was to document how the response to COVID‐19 impacted undergraduate students studying the principles of evolution in an introductory organismal biology class over time; specifically, how their study habits for exams differed (a) one week and (b) one month after a university's decision to transition to emergency remote instruction. The report that follows is a summary of the documented barriers and recommendations based on literature concerning crises and equitable practices.

An animal's pace of life is mediated by the physiological demands and stressors it experiences (e.g., reproduction) and one likely mechanism that underlies these effects is oxidative stress. Reproduction has been shown to increase or reduce oxidative stress under different conditions and modify mitochondrial performance. We hypothesized that the changes associated with reproduction can alter how animals respond to future oxidative stressors. We tested this theory by comparing the organ-specific mitochondrial response in female wild-derived house mice. Specifically, we compared mice that reproduced or were virgins to mice that were exposed to an oxidant (i.e., radiation) or not-exposed to radiation. We measured liver and skeletal muscle mitochondrial density, respiratory performance, enzyme activity, and oxidant production, as well as markers of oxidative damage to tissues. In the liver, prior reproduction prevented a radiation-induced reduction in mitochondrial density and increased mitochondrial respiratory performance. In skeletal muscle, prior reproduction resulted in a radiation-induced decline in mitochondrial density which could reduce the bioenergetic capacity of skeletal muscle mitochondria. Yet, electron transport chain complex I activity in skeletal muscle, which dropped with reproduction, returned to control levels following oxidant exposure. The results of this investigation indicate that prior reproduction alters the response of mitochondria to an oxidative challenge in an organ-specific manner. Such changes could have differential effects on future reproductive performance and risk of death.