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Widespread human development has led to the proliferation of artificial light at night, an increasingly recognized but poorly understood component of anthropogenic global change. Animals specialized to diurnal activity are presented opportunities to use this night-light niche, but the ecological consequences are largely unknown. While published records make note of nocturnal activity in a diversity of diurnal taxa, few case studies have gone beyond isolated observations to quantify patterns of nocturnal activity, document animal behavior, and describe new species interactions. From 13 June to 15 July 2017, we conducted hourly nocturnal surveys to assess how two species of diurnal Anolis lizards (Leach’s Anole, Anolis leachii, and Watt’s Anole, A. wattsi) use artificial light on Long Island, Antigua. Our data show that both anole species foraged in artificially illuminated habitats and were more active prior to sunrise compared to the early night. Mark-resight data for a focal species, A. leachii, suggest that patterns of nocturnal activity were not significantly different between individuals. Finally, our behavioral observations for the two anoles and a third lizard species, the nocturnal Thick-tailed Gecko (Thecadactylus rapicauda), reveal a lack of agonistic interactions. Our study reveals an altered temporal niche for two diurnal Antiguan lizards and adds to a growing body of evidence documenting the broad influences of anthropogenic change on biodiversity. 

Extreme climate events such as droughts, cold snaps, and hurricanes can be powerful agents of natural selection, producing acute selective pressures very different from the everyday pressures acting on organisms. However, it remains unknown whether these infrequent but severe disruptions are quickly erased by quotidian selective forces, or whether they have the potential to durably shape biodiversity patterns across regions and clades. Here, we show that hurricanes have enduring evolutionary impacts on the morphology of anoles, a diverse Neotropical lizard clade. We first demonstrate a transgenerational effect of extreme selection on toepad area for two populations struck by hurricanes in 2017. Given this short-term effect of hurricanes, we then asked whether populations and species that more frequently experienced hurricanes have larger toepads. Using 70 y of historical hurricane data, we demonstrate that, indeed, toepad area positively correlates with hurricane activity for both 12 island populations of Anolis sagrei and 188 Anolis species throughout the Neotropics. Extreme climate events are intensifying due to climate change and may represent overlooked drivers of biogeographic and large-scale biodiversity patterns. 

Abstract Adaptive radiation plays a fundamental role in our understanding of the evolutionary process. However, the concept has provoked strong and differing opinions concerning its definition and nature among researchers studying a wide diversity of systems. Here, we take a broad view of what constitutes an adaptive radiation, and seek to find commonalities among disparate examples, ranging from plants to invertebrate and vertebrate animals, and remote islands to lakes and continents, to better understand processes shared across adaptive radiations. We surveyed many groups to evaluate factors considered important in a large variety of species radiations. In each of these studies, ecological opportunity of some form is identified as a prerequisite for adaptive radiation. However, evolvability, which can be enhanced by hybridization between distantly related species, may play a role in seeding entire radiations. Within radiations, the processes that lead to speciation depend largely on (1) whether the primary drivers of ecological shifts are (a) external to the membership of the radiation itself (mostly divergent or disruptive ecological selection) or (b) due to competition within the radiation membership (interactions among members) subsequent to reproductive isolation in similar environments, and (2) the extent and timing of admixture. These differences translate into different patterns of species accumulation and subsequent patterns of diversity across an adaptive radiation. Adaptive radiations occur in an extraordinary diversity of different ways, and continue to provide rich data for a better understanding of the diversification of life. 

Abstract Seasonal changes in reproduction have been described for many taxa. As reproductive seasons progress, females often shift from greater energetic investment in many small offspring towards investing less total energy into fewer, better provisioned (i.e. larger) offspring. The underlying causes of this pattern have not been assessed in many systems.Two primary hypotheses have been proposed to explain these patterns. The first is an adaptive hypothesis from life‐history theory: early offspring have a survival advantage over those produced later. Accordingly, selection favours females that invest in offspring quantity early in the season and offspring quality later. The second hypothesis suggests these patterns are not intrinsic but result from passive responses to seasonal changes in the environment experienced by reproducing females (i.e. maternal environment).To disentangle the causes underlying this pattern, which has been reported in brown anole lizards (Anolis sagrei), we performed complementary field and laboratory studies. The laboratory study carefully controlled maternal environments and quantified reproductive patterns throughout the reproductive season for each female. The field study measured similar metrics from free ranging lizards across an entire reproductive season.In the laboratory, females increased relative effort per offspring as the reproductive season progressed; smaller eggs were laid earlier, larger eggs were laid later. Moreover, we observed significant among‐individual variation in seasonal changes in reproduction, which is necessary for traits to evolve via natural selection. Because these patterns consistently emerge under controlled laboratory conditions, they likely represent an intrinsic and potentially adaptive adjustment of reproductive effort as predicted by life‐history theory.The field study revealed similar trends, further suggesting that intrinsic patterns observed in the laboratory are strong enough to persist despite the environmental variability that characterizes natural habitats. The observed patterns are indicative of an adaptive seasonal shift in parental investment in response to a deteriorating offspring environment: allocating greater resources to late‐produced offspring likely enhances maternal fitness.