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Elucidating the selective forces shaping the diversity of vertebrate brains continues to be a major area of inquiry, particularly as it relates to cognition. Historically brain evolution was interpreted through the lens of relative brain size; however, recent evidence has challenged this approach. Investigating neuroanatomy at a finer scale, such as neuron number, can provide new insights into the forces shaping brain evolution in the context of information processing capacity. Ecological factors, such as the complexity of a species' habitat, place demands on cognition that could shape neuroanatomy. In this study, we investigate the relationship between neuron number and habitat complexity in three brain regions across six closely related anole species from Puerto Rico. After controlling for brain mass, we found that the number of neurons increased with habitat complexity across species in the telencephalon and 'rest of the brain,' but not in the cerebellum. Our results demonstrate that habitat complexity has shaped neuroanatomy in the Puerto Rican anole radiation and provide further evidence of the role of habitat complexity in vertebrate brain evolution.

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Hybridization facilitates recombination between divergent genetic lineages and can be shaped by both neutral and selective processes. Upon hybridization, loci with no net fitness effects introgress randomly from parental species into the genomes of hybrid individuals. Conversely, alleles from one parental species at some loci may provide a selective advantage to hybrids, resulting in patterns of introgression that do not conform to random expectations. We investigated genomic patterns of differential introgression in natural hybrids of two species of Caribbean anoles, Anolis pulchellus and A. krugi in Puerto Rico. Hybrids exhibit A. pulchellus phenotypes but possess A. krugi mitochondrial DNA, originated from multiple, independent hybridization events, and appear to have replaced pure A. pulchellus across a large area in western Puerto Rico. Combining genome-wide SNP datasets with bioinformatic methods to identify signals of differential introgression in hybrids, we demonstrate that the genomes of hybrids are dominated by pulchellus-derived alleles and show only 10%-20% A. krugi ancestry. The majority of A. krugi loci in hybrids exhibit a signal of non-random differential introgression and include loci linked to genes involved in development and immune function. Three of these genes (delta like canonical notch ligand 1, jagged1 and notch receptor 1) affect cell differentiation and growth and interact with mitochondrial function. Our results suggest that differential non-random introgression for a subset of loci may be driven by selection favouring the inheritance of compatible mitochondrial and nuclear-encoded genes in hybrids.

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This biographical account summarizes the professional career and scientific contributions of John Paul Richard Thomas, a contemporary leading figure in the systematics of West Indian amphibians and non-avian reptiles, especially of blind snakes of the families Typhlopidae and Leptotyphlopidae. Since his first expedition to the West Indies in 1957, Richard's vast field experience (including three trips to Peru between 1968 and 1974), impressive collecting skills, and remarkable ability to detect phenotypic variation among natural populations have resulted in the description of more than 70 species of snakes (24 typhlopids, 4 leptotyphlopids), lizards, and frogs in 16 genera and 11 taxonomic families. Richard joined the faculty of the Department of Biology, University of Puerto Rico, Río Piedras, in 1976 and ever since his efforts significantly advanced organismal biology research at the institution. Although primarily a systematist, his desire to understand multiple aspects of an organism's biology and contagious passion for becoming intimately familiar with animals in their natural environments provided his students the opportunity to conduct research in fields such as behavioral and evolutionary ecology. Richard's mentoring fostered the scientific interests of his graduate students, who were exposed first-hand to every aspect of research, an invaluable experience that served as a springboard for the development of their professional careers inside and outside academia. This Commentary is a fitting tribute to an influential, unassuming scientist whose passion for turning over rocks has led to the discovery of many interesting species.

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Abstract Introduction: Inverted papillomas represent one of the most common benign neoplasic lesions located in the sinonasal tract. Owing to the local erosive behavior, tendency to recur and the potential for malignant transformation, surgical management of inverted papillomas is often challenging. Objective: This study aimed to analyze the surgical outcomes of patients with inverted papillomas, according to the Krouse staging and the different surgical approaches. Methods: Retrospective study of patients diagnosed with sinonasal inverted papillomas who underwent surgical treatment between 2000 and 2016 at a tertiary referral hospital. Cases with follow-up less than 12 months were excluded. The rate and the time of recurrence were the main outcomes. Values of p < 0.05 were considered statistically significant. Results: Thirty-six cases with mean age of 60 years, predominantly male (72%), were included. The follow-up period ranged from 1 to 16 years, with an average of 4.5 years. Krouse T1 Stage corresponded to 11.1%; T2 occurred in 50% of cases; while T3 and T4 Stages accounted for 30.6% and 8.3% of patients, respectively. Most cases were approached by an endoscopic technique alone (83.3%), with a recurrence rate of 13.3%. Patients treated via a combined or open approach revealed a recurrence of 16.7%. No differences in the recurrence rate were reported when comparing endoscopic surgery with the open or combined techniques. Krouse Stage T3 had a significant association with inverted papillomas recurrence (p = 0.023). All inverted papilloma relapses occurred up to 2 years post-operatively. One case of malignant transformation was recorded (2.7%). Conclusion: Endoscopic surgery did not increase the recurrence rates and can be a safe and efficient alternative to open or combined techniques. The recurrence of inverted papillomas seem to be related to the persistence of the disease and tend to occur early after primary surgery. Krouse T3 Stages may be associated with a higher recurrence of inverted papillomas.

Resumo Introdução: Os papilomas invertidos são uma das lesões neoplásicas benignas mais comuns no trato nasossinusal. Devido ao seu comportamento localmente agressivo, tendência para recidivar e potencial de malignização, o tratamento cirúrgico dos papilomas invertidos constitui frequentemente um desafio. Objetivo: Analisar os resultados cirúrgicos dos papilomas invertidos segundo o estadiamento de Krouse, bem como avaliar as diferentes abordagens cirúrgicas. Método: Estudo retrospectivo de pacientes com diagnóstico de papiloma invertido nasossinusal submetidos a tratamento cirúrgico entre 2000 e 2016 em hospital terciário. Casos com acompanhamento inferior a 12 meses foram excluídos. A taxa e o tempo de recidiva foram os principais resultados analisados desfechos avaliados. Valores p < 0,05 foram considerados estatisticamente significativos. Resultados: Foram incluídos 36 casos, com média de idade de 60 anos, predominantemente do sexo masculino (72%). O período de acompanhamento variou de 1 a 16 anos, em uma média de 4,5 anos. Relativamente ao estadiamento, 11,1% dos pacientes foram classificados como estadio Krouse T1, 50% como T2, 30,6% como T3 e 8,3% como T4. A maioria dos casos foi tratada exclusivamente por cirurgia endoscópica (83,3%), com taxa de recidiva de 13,3%. Pacientes tratados com uma técnica combinada ou aberta apresentaram recidiva de 16,7%. Não foram observadas diferenças quanto à taxa de recidiva entre os casos abordados por via endoscópica e os casos tratados com técnica aberta ou combinada. Verificou-se uma associação significativa entre o estadio T3 de Krouse e recidiva de papilomas invertidos (p = 0,023). Todas as recidivas de papilomas invertidos foram observadas até dois anos após a cirurgia. Um caso de transformação maligna foi registrado (2,7%). Conclusão: A cirurgia endoscópica não aumentou as taxas de recidiva e pode ser uma alternativa segura e eficiente às técnicas abertas ou combinadas. Os casos de recidiva do papiloma invertido parecem estar relacionados com a persistência da doença e tendem a ocorrer precocemente após a cirurgia primária. Os estadios T3 de Krouse podem estar associados a uma maior recidiva.

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INTRODUCTION: Inverted papillomas represent one of the most common benign neoplasic lesions located in the sinonasal tract. Owing to the local erosive behavior, tendency to recur and the potential for malignant transformation, surgical management of inverted papillomas is often challenging. OBJECTIVE: This study aimed to analyze the surgical outcomes of patients with inverted papillomas, according to the Krouse staging and the different surgical approaches. METHODS: Retrospective study of patients diagnosed with sinonasal inverted papillomas who underwent surgical treatment between 2000 and 2016 at a tertiary referral hospital. Cases with follow-up less than 12 months were excluded. The rate and the time of recurrence were the main outcomes. Values of p<0.05 were considered statistically significant. RESULTS: Thirty-six cases with mean age of 60 years, predominantly male (72%), were included. The follow-up period ranged from 1 to 16 years, with an average of 4.5 years. Krouse T1 Stage corresponded to 11.1%; T2 occurred in 50% of cases; while T3 and T4 Stages accounted for 30.6% and 8.3% of patients, respectively. Most cases were approached by an endoscopic technique alone (83.3%), with a recurrence rate of 13.3%. Patients treated via a combined or open approach revealed a recurrence of 16.7%. No differences in the recurrence rate were reported when comparing endoscopic surgery with the open or combined techniques. Krouse Stage T3 had a significant association with inverted papillomas recurrence (p=0.023). All inverted papilloma relapses occurred up to 2 years post-operatively. One case of malignant transformation was recorded (2.7%). CONCLUSION: Endoscopic surgery did not increase the recurrence rates and can be a safe and efficient alternative to open or combined techniques. The recurrence of inverted papillomas seem to be related to the persistence of the disease and tend to occur early after primary surgery. Krouse T3 Stages may be associated with a higher recurrence of inverted papillomas.

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Elucidating how ecological and evolutionary mechanisms interact to produce and maintain biodiversity is a fundamental problem in evolutionary ecology. Here, we focus on how physiological evolution affects performance and species coexistence along the thermal niche axis in replicated radiations of Anolis lizards best known for resource partitioning based on morphological divergence. We find repeated divergence in thermal physiology within these radiations, and that this divergence significantly affects performance within natural thermal environments. Morphologically similar species that co-occur invariably differ in their thermal physiology, providing evidence that physiological divergence facilitates species coexistence within anole communities. Despite repeated divergence, phylogenetic comparative analyses indicate that physiological traits have evolved more slowly than key morphological traits related to the structural niche. Phylogenetic analyses also reveal that physiological divergence is correlated with divergence in broad-scale habitat climatic features commonly used to estimate thermal niche evolution, but that the latter incompletely predicts variation in the former. We provide comprehensive evidence for repeated adaptive evolution of physiological divergence within Anolis adaptive radiations, including the complementary roles of physiological and morphological divergence in promoting community-level diversity. We recommend greater integration of performance-based traits into analyses of climatic niche evolution, as they facilitate a more complete understanding of the phenotypic and ecological consequences of climatic divergence.

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The perception of visual stimuli has been a major area of inquiry in sensory ecology, and much of this work has focused on coloration. However, for visually oriented organisms, the process of visual motion detection is often equally crucial to survival and reproduction. Despite the importance of motion detection to many organisms' daily activities, the degree of interspecific variation in the perception of visual motion remains largely unexplored. Furthermore, the factors driving this potential variation (e.g., ecology or evolutionary history) along with the effects of such variation on behavior are unknown. We used a behavioral assay under laboratory conditions to quantify the visual motion detection systems of three species of Puerto Rican Anolis lizard that prefer distinct structural habitat types. We then compared our results to data previously collected for anoles from Cuba, Puerto Rico, and Central America. Our findings indicate that general visual motion detection parameters are similar across species, regardless of habitat preference or evolutionary history. We argue that these conserved sensory properties may drive the evolution of visual communication behavior in this clade.

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OBJECTIVE: To perform an extensive analysis of the immune status of asymptomatic children with the 22q11.2 deletion syndrome, with special emphasis on the regulatory T cells (Treg) population. STUDY DESIGN: Analysis of thymic function, frequency and absolute counts of immune subsets, and phenotype of Treg were performed in 10 asymptomatic children bearing the 22q11.2 deletion and compared with 12 age-matched, healthy children. RESULTS: Children with 22q11.2 deletion syndrome showed a curtailed thymic output, lower T-cell levels, and a homeostatic deregulation in the CD4 T-cell compartment, characterized by a greater proliferative history in the naïve CD4 T-cell subset. Treg numbers were markedly reduced in children with 22q11.2 deletion syndrome, and remaining Treg showed mostly an activated phenotype. CONCLUSIONS: Reduced thymic output in children with 22q11.2 deletion syndrome could be related with an increased proliferation in the naïve CD4 T-cell compartment and the consequent Treg activation to ensure that T-cell expansion remains under control. Deregulated peripheral homeostasis and loss of suppressive capacity by Treg could compromise the integrity of T-cell immunity during adulthood and play a relevant role in the increased incidence of autoimmune diseases reported in patients with the 22q11.2 deletion syndrome.

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The predominant view is that the thermal physiology of tropical ectotherms, including lizards, is not labile over ecological timescales. We used the recent introduction (∼35 years ago) of the Puerto Rican lizard Anolis cristatellus to Miami, Florida, to test this thermal rigidity hypothesis. We measured lower (critical thermal minimum [CT(min)]) and upper (critical thermal maximum [CT(max)]) thermal tolerances and found that the introduced population tolerates significantly colder temperatures (by ∼3°C) than does the Puerto Rican source population; however, CT(max) did not differ. These results mirror the thermal regimes experienced by each population: Miami reaches colder ambient temperatures than Puerto Rico, but maximum ambient temperatures are similar. The differences in CT(min) were observed even though lizards from both sites experienced nearly identical conditions for 49 days before CT(min) measurement. Our results demonstrate that changes in thermal tolerance occurred relatively rapidly (∼35 generations), which strongly suggests that the thermal physiology of tropical lizards is more labile than previously proposed.

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Patterns of brain evolution have been widely studied across vertebrates, with the bulk of studies using mammals and/or birds as model systems. Within these groups, species occupying different habitats have been shown to have divergent neuroanatomy, particularly with regard to differences in the relative size of different brain structures, correlated with differences in habitat complexity. We examined the pattern of allometric scaling across the telencephalon, dorsal cortex, dorsomedial cortex, medial cortex, dorsal ventricular ridge, medulla and cerebellum in six species of Puerto Rican Anolis lizards, which are grouped in three distinct ecomorphs (i.e. ecological types) according to interspecific differences in preferred habitat type. The differences in habitat preferences are accompanied by morphological and behavioral adaptations for effective use of each habitat type. Our results challenge this trend and demonstrate a lack of convergence in the relative size of different brain structures between species belonging to the same ecomorph type. Overall brain volume explained between 92.5 and 99.8% of the variance in the volume of each of the brain regions measured and 93.8 and 98.5% of the variance in the volume of each component measured within the telencephalon. This pattern of brain allometry is consistent with concerted brain evolution. However, in the case of the cerebellum, interspecific differences in volume exhibit a trend in accordance with mosaic brain evolution. This suggests that both concerted and mosaic brain evolution have shaped the anole brain, with the former playing a dominant role. Concerted brain evolution is the primary mechanism shaping the brain in mammals and cartilaginous fishes, and its presence in Anolis lizards provides additional evidence supporting the hypothesis that concerted brain evolution might result from a conserved pattern of brain development common to all vertebrates. More generally, our findings highlight the necessity of further studies of brain evolution in reptiles as they can provide valuable insights into the mechanisms underlying vertebrate brain evolution.

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The extent to which random processes such as founder events contribute to evolutionary divergence is a long-standing controversy in evolutionary biology. To determine the respective contributions of founder effects and natural selection, we conducted an experiment in which brown anole (Anolis sagrei) lizard populations were established on seven small islands in the Bahamas, from male-female pairs randomly drawn from the same large-island source. These founding events generated significant among-island genetic and morphological differences that persisted throughout the course of the experiment despite all populations adapting in the predicted direction-shorter hindlimbs-in response to the narrower vegetation on the small islands. Thus, using a replicated experiment in nature, we showed that both founder effects and natural selection jointly determine trait values in these populations.

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The role of behavioural flexibility in responding to new or changing environmental challenges is a central theme in cognitive ecology. Studies of behavioural flexibility have focused mostly on mammals and birds because theory predicts that behavioural flexibility is favoured in species or clades that exploit a diversity of habitats or food sources and/or have complex social structure, attributes not associated with ectothermic vertebrates. Here, we present the results of a series of experiments designed to test cognitive abilities across multiple cognitive modules in a tropical arboreal lizard: Anolis evermanni. This lizard shows behavioural flexibility across multiple cognitive tasks, including solving a novel motor task using multiple strategies and reversal learning, as well as rapid associative learning. This flexibility was unexpected because lizards are commonly believed to have limited cognitive abilities and highly stereotyped behaviour. Our findings indicate that the cognitive abilities of A. evermanni are comparable with those of some endothermic species that are recognized to be highly flexible, and strongly suggest a re-thinking of our understanding of the cognitive abilities of ectothermic tetrapods and of the factors favouring the evolution of behavioural flexibility.

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Phenotypic plasticity can contribute to the process of adaptive radiation by facilitating population persistence in novel environments. West Indian Anolis lizards provide a classic example of an adaptive radiation, in which divergence has occurred along two primary ecological axes: structural microhabitat and climate. Adaptive plasticity in limb morphology is hypothesized to have facilitated divergence along the structural niche axis in Anolis, but very little work has explored plasticity in physiological traits. Here, we experimentally ask whether Puerto Rican Anolis cristatellus from mesic and xeric habitats differ in desiccation rates, and whether these lizards exhibit an acclimation response to changes in relative humidity. We first present microclimatic data collected at lizard perch sites that demonstrate that abiotic conditions experienced by lizards differ between mesic and xeric habitat types. In Experiment 1, we measured desiccation rates of lizards from both habitats maintained under identical laboratory conditions. This experiment demonstrated that desiccation rates differ between populations; xeric lizards lose water more slowly than mesic lizards. In Experiment 2, lizards from each habitat were either maintained under the conditions of Experiment 1, or under extremely low relative humidity. Desiccation rates did not differ between lizards from the same habitat maintained under different treatments and xeric lizards maintained lower desiccation rates than mesic lizards within each treatment. Our results demonstrate that A. cristatellus does not exhibit an acclimation response to abrupt changes of hydric conditions, and suggest that tropical Anolis lizards might be unable to exhibit physiological plasticity in desiccation rates in response to varying climatic conditions.

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Two factors that can lead to geographic structuring in conspecific populations are barriers to dispersal and climatic stability. Populations that occur in different physiographic regions may be restricted to those areas by physical and/or ecological barriers, which may facilitate the formation of phylogeographic clades. Long-term climatic stability can also promote genetic diversification, because new clades are more likely to evolve in areas that experience lesser climatic shifts. We conducted a phylogeographic study of the Puerto Rican lizard Anolis krugi to assess whether populations of this anole show genetic discontinuities across the species' range, and if they do, whether these breaks coincide with the boundaries of the five physiographic regions of Puerto Rico. We also assessed whether interpopulation genetic distances in A. krugi are positively correlated with relative climatic stability in the island. Anolis krugi exhibits genetic structuring, but the phylogroups do not correspond to the physiographic regions of Puerto Rico. We used climatic reconstructions of two environmental extremes of the Quaternary period, the present conditions and those during the last glacial maximum (LGM), to quantify the degree of climatic stability between sampling locations. We documented positive correlations between genetic distances and relative climatic stability, although these associations were not significant when corrected for autocorrelation. Principal component analyses indicated the existence of climatic niche differences between some phylogeographic clades of A. krugi. The approach that we employed to assess the relationship between climatic stability and the genetic architecture of A. krugi can also be used to investigate the impact of factors such as the spatial distribution of food sources, parasites, predators or competitors on the genetic landscape of a species.

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Species with restricted geographic distributions consisting of isolated populations are particularly susceptible to extinction because these demes face an increased risk of disappearing due to environmental, demographic, and genetic stochasticity. We used partial DNA sequences of the cytochrome b (1083 bp) and ND2 (1041 bp) mitochondrial genes to investigate the phylogeography and population genetics of Anolis cooki, a threatened lizard endemic to the southwestern coast of the Caribbean Island of Puerto Rico. Maximum likelihood and Bayesian methods revealed relatively shallow genetic differentiation among 27 unique haplotypes (from 52 individuals) from the known extant populations of A. cooki in mainland Puerto Rico. Despite this pattern, specimens from the same geographic area tended to nest together. The most basal division within A. cooki is between haplotypes from the three westernmost populations (Punta Aguila, Morrillos, Playa Santa) and the remainder demes (Bahía Ballena, La Cueva, Punta Verraco). The three westernmost populations of A. cooki are separated from their conspecific demes by the Guánica Bay and the Loco River drainage system, which together may represent a physiographic barrier for A. cooki. Each population of A. cooki only has private haplotypes; in other words, there are no shared mitochondrial types between populations. Because the number of private haplotypes can be used as an indirect measure of gene flow, this finding suggests that currently there is no migration among demes, and that each is an independent demographic unit, despite the relatively short distances (ca. 2 km) that separate some of them. Pairwise F(ST) values and spatial analyses of molecular variation confirmed the existence of distinct groups of genetically defined sampling areas, and of significant molecular variation among populations within groups and within populations. The conservation status of the populations of A. cooki varies greatly. The demes from Punta Aguila, Morrillos, and Bahía Ballena inhabit protected areas, and are larger, genetically diverse, and seemingly stable. The population from Playa Santa showed a high level of genetic diversity, but it occurs in an area that has been intensively developed for residential and touristic purposes, and its long-term survival is uncertain. A. cooki is also known from Caja de Muertos, an island off the southcentral coast of Puerto Rico. Surveys conducted on September 2006 and March 2007 did not produce any specimens, and a thorough assessment of Caja de Muertos is needed to determine the present status of A. cooki on the island.

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We tested the prediction of the sensory drive hypothesis using four allopatric populations of the lizard Anolis cristatellus from two distinct environments (i.e., mesic and xeric conditions). For each population, we measured habitat light characteristics and quantified signal design by measuring the spectral and total reflectance and transmittance of the dewlap. We used these data to calculate dewlap detectability using an empirically based model of signal detection probability. We found that populations from mesic and xeric conditions occupy two distinct habitats with respect to light intensity and spectral quality and that dewlap design has diverged between populations in a way that increases signal detectability in each habitat. The major difference in dewlap design was in total reflectance and transmittance, making dewlaps from xeric habitats darker and dewlaps from mesic habitats brighter. Furthermore, dewlap detection decreased significantly when a dewlap from a xeric habitat is detected under the spectral conditions of a mesic habitat. The converse is true for a dewlap from a mesic habitat. We propose that sensory drive has promoted divergence in dewlap design in distinct habitat light conditions, and we discuss the possibility that selection might promote early stages of reproductive isolation as a by-product of selection on dewlap design to distinct habitat light conditions.

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Niche conservatism--the tendency for closely related species to be ecologically similar--is widespread. However, most studies compare closely related taxa that occur in allopatry; in sympatry, the stabilizing forces that promote niche conservatism, and thus inhibit niche shifts, may be countered by natural selection favouring ecological divergence to minimize the intensity of interspecific interactions. Consequently, the relative importance of niche conservatism versus niche divergence in determining community structure has received little attention. Here, we examine a tropical lizard community in which species have a long evolutionary history of ecological interaction. We find that evolutionary divergence overcomes niche conservatism: closely related species are no more ecologically similar than expected by random divergence and some distantly related species are ecologically similar, leading to a community in which the relationship between ecological similarity and phylogenetic relatedness is very weak. Despite this lack of niche conservatism, the ecological structuring of the community has a phylogenetic component: niche complementarity only occurs among distantly related species, which suggests that the strength of ecological interactions among species may be related to phylogeny, but it is not necessarily the most closely related species that interact most strongly.

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Terrestrial habitats exhibit a variety of light environments. If species exhibit evolutionary adaptations of their visual system or signals to habitat light conditions, then these conditions can directly influence the structure of communities. We evaluated habitat light characteristics and visual-signal design in a pair of sympatric species of lizards: Anolis cooki and Anolis cristatellus. We found that each species occupies a distinct microhabitat with respect to light intensity and spectral quality. We measured the relative retinal spectral sensitivity and found significant differences between the species that correlate with differences in habitat spectral quality. We measured the spectral reflectance of the dewlaps (colourful throat fans used in communication), and found that the A. cooki dewlap reflects little ultraviolet (UV), while that of A. cristatellus reflects strongly in the UV. For both species downwelling light (irradiance) is rich in UV. However the background light (radiance) is rich in UV for A. cooki, but low in UV for A. cristatellus. Thus, the dewlap of each species creates a high contrast with the background in the UV. Our findings strongly suggest that these two species are partitioning their habitat through specializations of the visual system and signal design to microhabitat light conditions.

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