Vertebrates display a wide variety of sex-determining mechanisms (SDMs). Identifying SDMs for different taxa is important for understanding the origins and phylogenetic history of sex-determining mechanisms. Temperature-dependent sex determination (TSD) is found in several vertebrate and invertebrate species, and has been studied most extensively in reptiles. The initial discovery of TSD was in a lizard, the African redhead agama (Agama agama), over 50 years ago. The original study of A. agama used only two incubation temperature treatments and had a small sample size, thus it could not fully characterize the pattern of TSD in this species. The goal of this study is to revisit this research to better characterize the pattern of TSD. We also assessed the effect of fluctuating incubation temperatures on offspring sex ratio to provide insight into how variation in offspring sex ratio is produced under natural conditions. After incubating eggs across six constant temperature treatments, we demonstrated that females are produced at relatively cool temperatures and males at warmer temperatures (30°C); fluctuating thermal regimes showed this same pattern. However, some females are again produced at even warmer temperatures, resulting in relatively balanced sex ratios toward the end of the sex-determining reaction norm. Though the shape of the sex-determining reaction norm shown here is unusual, it shows some similarities to that of other agamid lizards. Future studies that explore the diversity of TSD reaction norms and underlying physiological mechanisms will provide new insights into the evolution of TSD.

The developmental environment plays a pivotal role in shaping fitness-relevant phenotypes of all organisms. Phenotypes are highly labile during embryogenesis, and environmental factors experienced early in development can have profound effects on fitness-relevant traits throughout life. Many reptiles exhibit temperature-dependent sex determination (TSD), whereby temperature during embryonic development permanently determines offspring sex. The leading hypothesis for the adaptive significance of TSD posits that egg incubation temperature differentially affects the fitness of males vs. females so that each sex is produced at its optimal temperature. The goal of this research is to address this hypothesis by quantifying the sex-specific effects of incubation temperature on phenotypes and survival in a lizard (Agama picticauda) with TSD. By incubating eggs under constant and fluctuating temperatures, we demonstrated that incubation temperature affects fitness-relevant phenotypes in A. picticauda; but males and females had similar reaction norms. However, females produced from female-biased incubation temperatures had greater survival than those from male-biased temperatures, and male survival was lowest for individuals produced from a female-biased temperature. In addition, eggs incubated at male-biased temperatures hatched earlier than those incubated at female-biased temperatures, which may have sex-specific consequences later in life as predicted by models for the adaptive significance of TSD.

Student struggle in undergraduate biology is largely correlated with incoming preparation, instructor, and course performance. In this study, students often attributed their struggle to external sources (i.e., classroom factors, external resources, etc.); however, they were more likely to overcome internal sources of struggle.

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Aim/Purpose: Our goal is to provide understanding of if and how the institutional factors found to contribute to a chilly climate are experienced in an international setting and provide a broader understanding of the discourses that create challenges for marginalized and underrepresented groups in STEM. Background: In August 2018 the Hungarian government stopped funding gender studies program and took direct control of funding at the Hungarian Academy of Sciences in order to focus “taxpayer money on areas that can generate a payoff for society” (Witte, 2018). Methodology: Data collection and analysis focused on how the interface between students and mathematics education was organized as a matter of the everyday encounters between students and faculty and administration by exploring their experiences inside and outside of the classroom. Contribution: There is little in the scholarly literature on how the recent threats and policy changes by the Hungarian government will impact Hungarian higher education; as such, this research has the potential to be a significant and leading contribution to the field by critically examining how ongoing changes to higher education policy, practices, and procedures in Hungary impacts the educational environment for students seeking a graduate degree in Hungary. Findings: Although students and faculty at IU were aware of the political discourses surrounding higher education in Hungary, they largely felt that their work as mathematicians was not largely impacted by threats to academic freedom and institutional autonomy. Instead, these findings suggest that many of the same discourses that coordinate the work of STEM students in higher education persisted to create similar challenges for IU mathematics students. Recommendations for Practitioners: The first step toward improving the chilly climate in STEM fields requires revising the STEM institution from one that is masculine to one that is inclusive for all students with the goal of creating a STEM education environment that supports, validates, and gives students an equal voice. Recommendation for Researchers: Subsequent inquiries guided by this work can extend to additional institutional environments in Hungary and in other authoritarian countries where academic freedom and institutional autonomy are challenged in order to understand how political reform and institutional factors play a role in creating challenges for students from underrepresented groups. Impact on Society: By providing an international perspective, we can explore trends in institutional factors in order to make recommendations that mitigate or reverse the traditional competitive and intimidating STEM classroom environment. Future Research: Future inquiries can explore discourses that contribute to the chilly climate in STEM with an international perspective, to explore if these discourses are consistent across different types of universities around the world.