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Consistent individual differences in behavior, known as behavioral individuality, are pervasive across the animal world and have major ecological and evolutionary consequences. Nevertheless, we still have a limited understanding of what drives individuality and how it emerges during ontogeny. Here, we subjected clonal individuals to a ubiquitous yet critical environmental challenge—the threat of predation—to disentangle the developmental mechanisms of individuality. Under such a salient environmental stressor, among-individual differences may collapse or expand depending on whether there is a single or multiple optimal strategies, demonstrating that individuality itself is a developmentally plastic trait. If, however, the environment does not impact among-individual variation, this suggests that individuality is determined before birth. We continuously tracked the behavior of genetically identical fish (Amazon mollies, Poecilia formosa), reared with or without predation stress, from birth through their first month of life. Predation shifted mean-level behaviors, with predator-exposed individuals swimming more slowly and spending more time near their refuges. However, the magnitude of individuality (as evidenced by repeatability) increased similarly over development in both treatments, indicating that individuality crystallizes robustly over time, even under stress and in a vacuum of genetic variation. Predator-reared fish also exhibited greater within-individual variability in refuge use, suggesting increased behavioral flexibility or disrupted developmental canalization in response to stress. Surprisingly, maternal identity, but not maternal behavior, was the strongest predictor of swimming speed, pointing to non-behavioral maternal effects as a key pre-birth source of behavioral variation. Refuge use however was not at all predicted by maternal identity, indicating that major fitness-related behaviors can have entirely different developmental mechanisms. Collectively, we show that individuality persists despite environmental stress and is seeded before birth through non-genetic factors. Even in the face of a shared environmental challenge, the behavioral trajectories of individuals are unique. 

Residents of communities increasingly rely on geographically focused groups on online social media platforms to access local information. These local groups have the potential to enhance the quality of life in communities by helping residents learn about their communities, connect with neighbors and local organizations, and identify important local issues. Moderators of online community groups—typically untrained volunteers—are key actors in these spaces. However, they are also put in a tenuous position, having to manage the groups while simultaneously navigating desires of platforms, rapidly evolving user practices, and the increasing politicization of local issues. In this paper, we explicate the visions of local community groups put forward by Facebook, Reddit, and NextDoor in their corporate discourse and ask: How do these platforms describe local community groups, particularly in reference to ideal communication and community engagement that occurs within them, and how do they position volunteer moderators to help realize these ideals? Through a qualitative thematic analysis of 849 company documents published between 2012 and 2023, we trace how each company rhetorically positions these spaces as what we refer to as a “local platformized utopias.” We examine how this discourse positions local volunteer moderators, the volunteer labor-force of civic actors that constructs, governs, and grows community groups. We discuss how these three social media companies motivate moderators to do this free, value-building labor through the promise of civic virtue; simultaneously obscuring unequal burdens of moderation labor and failing to address the inequalities of access to voice and power in online life. 

Stress quantification can be observed during single fiber pull-out test in a polymer matrix composite with stress sensing molecules. 

The social media industry has begun more prominently positioning itself as a vehicle for tapping into local community. Facebook offers hundreds of region-specific community groups, proudly touting these in nation-wide commercials. Reddit has hundreds of subreddits focused on specific states, cities, and towns. And Nextdoor encourages users to sign up and “Get the most out of your neighborhood.” In these locally oriented digital spaces, users interact, discuss community issues, and share information about what is happening around them. Volunteer moderators with localized knowledge are important agents in the creation, maintenance, and upkeep of these digital spaces. And, as we show, Facebook, Reddit, and Nextdoor create strategic communication to guide this localized volunteer moderator labor to realize specific goals within these spaces. In this work, we ask: “What are the promises the social media industry make about local community groups, and how do they position volunteer moderators to help realize those promises?” Through a qualitative content analysis of 849 documents produced by Facebook, Reddit, and NextDoor, we trace how platforms position their version of local community as slightly different utopian spaces, and channel volunteer moderator labor both through direct instruction and appeals to civic virtue. 

Abstract Millions of years of evolution have optimized many biosynthetic pathways by use of multi‐step catalysis. In addition, multi‐step metabolic pathways are commonly found in and on membrane‐bound organelles in eukaryotic biochemistry. The fundamental mechanisms that facilitate these reaction processes provide strategies to bioengineer metabolic pathways in synthetic chemistry. Using Brownian dynamics simulations, here we modeled intermediate substrate transportation of colocalized yeast–ester biosynthesis enzymes on the membrane. The substrate acetate ion traveled from the pocket of aldehyde dehydrogenase to its target enzyme acetyl‐CoA synthetase, then the substrate acetyl CoA diffused from Acs1 to the active site of the next enzyme, alcohol‐O‐acetyltransferase. Arranging two enzymes with the smallest inter‐enzyme distance of 60 Å had the fastest average substrate association time as compared with anchoring enzymes with larger inter‐enzyme distances. When the off‐target side reactions were turned on, most substrates were lost, which suggests that native localization is necessary for efficient final product synthesis. We also evaluated the effects of intermolecular interactions, local substrate concentrations, and membrane environment to bring mechanistic insights into the colocalization pathways. The computation work demonstrates that creating spatially organized multi‐enzymes on membranes can be an effective strategy to increase final product synthesis in bioengineering systems.