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Urban informal settlements, more commonly known as slums, are hotspots for the environmental transmission of antimicrobial resistance (AMR). Here, the authors discuss the behavioural, environmental and structural reasons for this and propose that improvements in water and waste infrastructure, as well as legal and economic incentives, could limit environmental AMR dissemination.
In this Perspective, Lopez-Garcia and Moreira update the Syntrophy hypothesis for the origin of eukaryotes, considering recent advances in the archaeal field about the physiology, metabolism, ecology and evolution of these microbes. They also compare and contrast their model with alternative ones, such as the classical Searcy’s and Hydrogen hypotheses and the more recent Reverse Flow and Entangle–Engulf–Endogenize models, and discuss model predictions and ways to test these.