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The dentition is an extremely important organ in mammals with variation in timing and sequence of eruption, crown morphology, and tooth size enabling a range of behavioral, dietary, and functional adaptations across the class. Within this suite of variable mammalian dental phenotypes, relative sizes of teeth reflect variation in the underlying genetic and developmental mechanisms. Two ratios of postcanine tooth lengths capture the relative size of premolars to molars (premolar-molar module, PMM), and among the three molars (molar module component, MMC), and are known to be heritable, independent of body size, and to vary significantly across primates. Here, we explore how these dental traits vary across mammals more broadly, focusing on terrestrial taxa in the clade of Boreoeutheria (Euarchontoglires and Laurasiatheria). We measured the postcanine teeth of N = 1,523 boreoeutherian mammals spanning six orders, 14 families, 36 genera, and 49 species to test hypotheses about associations between dental proportions and phylogenetic relatedness, diet, and life history in mammals. Boreoeutherian postcanine dental proportions sampled in this study carry conserved phylogenetic signal and are not associated with variation in diet. The incorporation of paleontological data provides further evidence that dental proportions may be slower to change than is dietary specialization. These results have implications for our understanding of dental variation and dietary adaptation in mammals.

Molar and incisor microwear reflect aspects of food choice and ingestive behaviors in living primates and have both been used to infer the same for fossil samples. Canine microwear, however, has received less attention, perhaps because of the prominent role canines play in social display and because they are used as weapons–while outside of a few specialized cases, their involvement in diet related behaviors has not been obvious. Here, we posit that microwear can also provide glimpses into canine tooth use in ingestion. Canines of Sumatran long‐tailed macaques (Macaca fascicularis), agile gibbons (Hylobates agilis), lar gibbons (Hylobates lar), Thomas' leaf monkeys (Presbytis thomasi), and orangutans (Pongo abelii), and two African great apes, bonobos (Pan paniscus) and common chimpanzees (Pan troglodytes schweinfurthii), were considered. The labial tips of maxillary canine replicas were scanned using a white‐light confocal profiler, and both feature and texture analyses were used to characterize microwear surface patterning. The taxa exhibited significant differences in canine microwear. In some cases, these were consistent with variation in reported anterior tooth use such that, for example, the orangutans, known to use their front teeth extensively in ingestion, had the highest median number of microwear features on their canines, whereas the gibbons, reported to use their front teeth infrequently in food acquisition, had the lowest. Research Highlights: Canine microwear patterns of catarrhine primates are independent of the shapes of these teeth (i.e., "stubby" vs. "stabby").Variation in canine microwear patterns among Sumatran anthropoid primates, especially gibbons and orangutans, reflect broad differences in anterior tooth use reported in the literature.Canine microwear holds the potential to reveal insights into ingestive behaviors in past primates. [ABSTRACT FROM AUTHOR]

Science, engineering, and society increasingly require integrative thinking about emerging problems in complex systems, a notion referred to as convergence science. Due to the concurrent pressures of two main stressors—rapid climate change and industrialization, Arctic research demands such a paradigm of scientific inquiry. This perspective represents a synthesis of a vision for its application in Arctic system studies, developed by a group of disciplinary experts consisting of social and earth system scientists, ecologists, and engineers. Our objective is to demonstrate how convergence research questions can be developed via a holistic view of system interactions that are then parsed into material links and concrete inquiries of disciplinary and interdisciplinary nature. We illustrate the application of the convergence science paradigm to several forms of Arctic stressors using the Yamal Peninsula of the Russian Arctic as a representative natural laboratory with a biogeographic gradient from the forest‐tundra ecotone to the high Arctic. Plain Language Summary: This paper represents a synthesis of conceptual analyses, case study analyses, and practical thoughts on the application of convergence science in Arctic change studies. During a virtual workshop in 2020, a diverse, multi‐national team of authors consisting of social scientists, engineers, earth system scientists, and ecologists came together to formulate broad, scientifically, and societally important questions on how the Arctic system in the Yamal Peninsula of Western Siberia responds to pressures of rapidly changing climate and increasing industrialization. The team "engineered" a novel approach for expert (representing a disciplinary domain) and non‐expert (representatives of other disciplines) communication and at the workshop conclusion developed several convergence science questions of high appeal. Three of such questions are presented in this manuscript to illustrate how the search and identification of appropriate mechanistic linkages are critical to the development of system‐level understanding of stressor impact propagation. The need to understand underlying disciplinary and cross‐disciplinary mechanisms connecting Arctic system elements is viewed to be an inherent part of the convergence science approach. Through pursuit of such understanding, the approach naturally leads to other novel emerging questions, thereby stimulating further application of the process of integrative thinking. Key Points: Arctic research demands convergence science as essential method to understand impacts from novel stressorsAn integrative approach is developed by a diverse team to formulate questions that cannot be fully addressed within disciplinary studiesA convergence science analysis is illustrated for three questions applicable to Yamal, Russian Arctic, a microcosm of the changing Arctic [ABSTRACT FROM AUTHOR]