The monarch butterfly, Danaus plexippus, is famous for its spectacular annual migration across North America, recent worldwide dispersal, and orange warning coloration. Despite decades of study and broad public interest, we know little about the genetic basis of these hallmark traits. By sequencing 101 monarch genomes from around the globe, we uncover the history of the monarch's evolutionary origin and global dispersal, characterize the genes and pathways associated with migratory behavior, and identify the discrete genetic basis of warning coloration. The results rewrite our understanding of this classic system, showing that D. plexippus was ancestrally migratory and dispersed out of North America to occupy its broad distribution. We find the strongest signatures of selection associated with migration center on flight muscle function, resulting in greater flight efficiency among migratory monarchs, and that variation in monarch warning coloration is controlled by a single myosin gene not previously implicated in insect pigmentation.

Student stress and anxiety often negatively impact students’ academic performance. This Essay provides summaries of different evidence-based strategies, ranging from changes in instructional strategies to specific classroom interventions, that instructors can employ to address and ameliorate student stress and anxiety.

The transition to online learning in spring 2020 was abrupt for both students and instructors. While many instructors moved to asynchronous classes, some institutions relied more heavily on synchronous online courses. Here, we evaluate student perceptions of an inquiry-based molecular biology lecture and lab course following this transition by comparing student survey responses from spring 2019, when the lecture and lab were fully in person, to spring 2020, when the lecture and lab started in person before transitioning to a synchronous online format. Students were asked to identify the main factors that supported their learning in lecture and lab, characterize the main barriers to learning in those courses, and discuss their preference of having an inquirybased lab or a traditional "cookbook" lab with predetermined answers. We coded these responses and provide one of the first studies to examine the impact of this online transition on student perceptions of learning in an inquiry-based molecular biology lecture and lab course.

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