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Polystable phenomena have been extensively studied to understand the constructive nature of perception (e.g., the Necker cube, duck-rabbit, binocular rivalry). A new polystable phenomenon, illusory apparent motion (IAM), with unique properties was recently discovered (Davidenko et al., 2017). IAM is generated in randomly refreshing pixel arrays. As a result, IAM, unlike other polystable phenomena, affords potentially counterless interpretations of the pixel motion and observers may not automatically experience an initial interpretation, instead having to rely on self-generated initial percepts. These unique properties of IAM raise a plethora of questions. In light of IAM’s unique properties, the four experiments presented here explore questions about the nature of subjective control of IAM. Experiments 1 and 2 ask whether observers can mentally control their perception of IAM (a feature common in other polystable phenomena). Experiment 1 explores this question using a motion priming and persistence task, based on the methods of Davidenko et al. (2017). Participants were presented with a series of priming frames that transitioned to frames of pure noise and reported with a single button press when the initial motion pattern appeared to change. Experiment 1 found that observers were able to mentally control IAM, evidenced by extended motion persistence when they were instructed to ‘hold’ and shortened motion persistence when they were instructed to ‘change.’ Experiment 2 explores the same question, but in a methodological context more in line with past subjective controls studies (Kohlers et al., 2008). For this task, participants were not assisted with motion primes, instead self-generating initial motion patterns, and reported their percepts dynamically throughout the trial. Experiment 2 found that participants were able to control their perception of IAM in this new, possibly more demanding, experimental context. Together, the results of Experiments 1 and 2 demonstrate that participants can subjectively control their perceptions of IAM. Experiment 3 explored questions about the potentially countless interpretations of IAM: how many interpretations of IAM can observers perceive and subjectively control? Experiment 3 tested 14 different motion types, half of which were motion types not yet explored in IAM studies (i.e., containing expansion, contraction, and shearing motion patterns). For each trial, participants were informed about one of the 14 motion types of instruction and, for one block, reported when they happened to perceive the instructed motion. In another block, participants were instructed to try and ‘hold’ the instructed motion. Experiment 3 found that observers were able to perceive many and control a few interpretations of IAM, supporting previous assumptions that observers likely experience more interpretations of IAM than other polystable phenomena. The last study, Experiment 4, explored whether it was possible to quantify some of the low- and high-level factors that can influence participants’ perception of IAM (e.g., subjective control, motion biases, motion coherence). To test this, participants were presented with two priming frames, followed by two test frames. The test frames were manipulated to present participants with (1) a nulling (prime-inconsistent) motion below and above their perceptual threshold, (2) with a facilitating (prime-consistent) motion below and above their perceptual threshold, and (3) with 0% motion. After each trial, participants reported the direction of motion that they perceived on the final two frames. Experiment 4 demonstrates that it’s possible to quantify a number of factors, including: the strength of the rebound bias, subjective control, motion nulling, and motion facilitation.Taken together, Experiments 1-4 lay the initial groundwork for exploring subjective control of IAM. Together they demonstrate subjective control in a variety of task conditions, suggest which motion types participants can control, and quantify the strength of subjective control.

The data provided here is related to the article “Resolving the Deep Phylogeny: Implications for Early Adaptive Radiation, Cryptic, and Present-day Ecological Diversity of Papuan Microhylid Frogs” [1]. The dataset is based on 233 tissue samples of the subfamily Asteroprhyinae, with representatives from all recognized genera, in addition to three outgroup taxa. The sequence dataset contains over 2400 characters per sample for five genes (three nuclear loci: BDNF, NXC-1, and SIA; and two mitochondrial loci: ND4 and CYTB) and is 99% complete. New primers were designed for all loci and accession numbers for the raw sequence data are provided. The sequences are used with geological time calibrations to produce time-calibrated Bayesian inference and Maximum Likelihood phylogenetic reconstructions using BEAST2 and IQTREE. Lifestyle data (arboreal, scansorial, terrestrial, fossorial, semi-aquatic) were collected from the literature and field notes and used to infer ancestral character states for each lineage. Collection location data (GPS and elevation data) were used to verify sites where multiple species or candidate species co-occur. All sequence data, alignments, and associated metadata (voucher specimen number, species identification, type locality status, GPS, elevation, site with species list, and lifestyle) as well as the code to produce all analyses and figures are provided.

Studies of the Papuan region have provided fundamental insights into both the evolutionary processes generating its exceptional biodiversity, as well support for alternative hypotheses of geological history. Lying at the junction of five tectonic plates, this region has experienced a turbulent geological history that has not only produced towering mountains allowing elevational specialization, and island archipelagos of varying distance promoting vicariance, but also active margins where land masses have collided and been subsequently rifted apart creating a mosaic of intermixed terranes with vastly different geological histories which may influence the evolutionary history of its biota. Asterophryine frogs are a hyperdiverse clade representing half the world’s microhylid diversity (over 360 species) centered on New Guinea and its satellite islands. We show that vicariance facilitated by geological history, and not elevational specialization best explain this far and wide distribution of a clade that should have poor dispersal abilities. Thus, some of the predictions of island biogeography theory are supported if informed by geological history. We recovered a mainland tectonic unit, the East Papua Composite Terrane (EPCT), as the center of origin for Asterophryinae and no fewer than 71 instances of what appear to be long-distance dispersal events, 29 of which are between mainland regions, with 42 from the mainland to the islands, some presently as far as 200 km away from source populations over open ocean. Furthermore, we find strong support for a “Slow and Steady” hypothesis for the formation of the northern margin of New Guinea by many separate accretion events during the Miocene, over other major geological alternatives, consistent with the 20 M year age of the clade and arrival via the EPCT. In addition, the historical biogeography of our frogs strongly support an affiliation of the Louisiade Archipelago and Woodlark Island with the Owen Stanley Mountain range on the EPCT, and the recent proximity of the large New Britain island. Our results show that Asterophryinae did not have to repeatedly and independently disperse across and large ocean barriers to the offshore islands, but that the current distribution can be explained through vicariance and short-distance oceanic dispersal as historical land connections disappeared and islands slowly became separated from each other. We show that islands have a life history, undergoing changes in area through island-building and erosion, but also change in distance from other land masses, with consequent opportunities for dispersal, isolation, and cladogenesis of their biotas. More broadly, we can begin to see how the geological history of the Papuan region can result in the rapid accumulation and staggering number of extant species.

The skink genus Lobulia is endemic to New Guinea, the largest and highest tropical island in the world. Lobulia and its related genera represent an important component of the montane herpetofauna of New Guinea, but it remains understudied and poorly known. We here provide the first, large-scale, systematic revision of Lobulia, using molecular phylogenetic and morphological comparisons to assess the monophyly of the genus and the diversity of species within it. We find that Lobulia, as currently defined, is polyphyletic. The eight species currently assigned to it form three clades. Furthermore, many specimens from New Guinea of unknown specific affinity are genetically and morphologically distinct from each other. Based on these data, we re-diagnose Lobulia and two of its closely related genera, Prasinohaema and Papuascincus. We erect four new genera (Alpinoscincus gen. nov., Nubeoscincus gen. nov., Ornithuroscincus gen. nov. and Palaia gen. nov.) to address the problem of polyphyly and describe nine new species Lobulia fortis sp. nov., Lobulia huonensis sp. nov., Loublia marmorata sp. nov., Lobulia vogelkopensis sp. nov., Ornithuroscincus bengaun sp. nov., Ornithuroscincus inornatus sp. nov., Ornithuroscincus pterophilus sp. nov., Ornithuroscincus shearmani sp. nov. and Ornithuroscincus viridis sp. nov. We supplement this taxonomic revision by investigating the biogeographic history of Lobulia s.l. and find evidence for a large radiation in the accreted terranes of New Guinea, with multiple independent colonizations of montane habitats and subsequent recolonization of lowland habitats. Our study reinforces the uniqueness and richness of the montane herpetofauna of New Guinea and the importance of mountains to biodiversity in the Tropics., This work was supported by a Binational Science Foundation grant 2012143 to S.M. and A.A., a Naomi Foundation through the Tel Aviv University GRTF programme grant 064181317 to A.S., National Science Foundation grants DEB-0103794 and DEB-0743890 to F.K. and A.A. A.S. is supported by a Royal Society grant RGF\EA\181082.

Comprehensive assessments of species’ extinction risks have documented the extinction crisis1 and underpinned strategies for reducing those risks2. Global assessments reveal that, among tetrapods, 40.7% of amphibians, 25.4% of mammals and 13.6% of birds are threatened with extinction3. Because global assessments have been lacking, reptiles have been omitted from conservation-prioritization analyses that encompass other tetrapods4–7. Reptiles are unusually diverse in arid regions, suggesting that they may have different conservation needs6. Here we provide a comprehensive extinction-risk assessment of reptiles and show that at least 1,829 out of 10,196 species (21.1%) are threatened—confirming a previous extrapolation8 and representing 15.6 billion years of phylogenetic diversity. Reptiles are threatened by the same major factors that threaten other tetrapods—agriculture, logging, urban development and invasive species—although the threat posed by climate change remains uncertain. Reptiles inhabiting forests, where these threats are strongest, are more threatened than those in arid habitats, contrary to our prediction. Birds, mammals and amphibians are unexpectedly good surrogates for the conservation of reptiles, although threatened reptiles with the smallest ranges tend to be isolated from other threatened tetrapods. Although some reptiles—including most species of crocodiles and turtles—require urgent, targeted action to prevent extinctions, efforts to protect other tetrapods, such as habitat preservation and control of trade and invasive species, will probably also benefit many reptiles.

The microhylid frogs of the New Guinea region are the largest and most ecologically diverse subfamily (Asterophryinae) of one of the largest anuran families in the world and can live in communities of up to 20 species. While there has been recent progress in resolving the phylogenetic relationships of Asterophryinae, significant uncertainties remain, impeding further progress in understanding the evolution of microhabitat use, parental care, and life history variation in this group. In particular, the early divergences at the base of the tree remain unclear; as does the monophyly of some genera; and recent studies have discovered that species with wide geographic distribution are instead cryptic species complexes. In this study, we fortified geographic sampling of the largest previous phylogenetic effort by sequencing an additional 62 taxa and increased data quality and quantity by adding new layers of data vetting and by filling in previously incomplete loci to the five gene dataset (2 mitochondrial, 3 nuclear protein-coding genes) to obtain a dataset that is now 99% complete in over 2400 characters for 233 samples (205 taxa) of Asterophryinae and 3 outgroup taxa, and analyzed microhabitat use data for these taxa from field data and data collected from the literature. Importantly, our sampling includes complete community complements at 19 sites as well as representatives at over 80 sites across New Guinea and its offshore islands. We present a highly resolved molecular phylogeny which, for the first time, has over 95% of nodes supported (84% highly supported) whether using Maximum Likelihood or Bayesian Inference, allowing clarification of all genera (whether monophyletic or clearly not), their sister genera relationships, as well as an age estimate for the Asterophryinae at approximately 20MYA. Early generic diversification occurring between 17 and 12 MYA gave rise to a surprising diversity of about 18 genera as well as the 5 putative microhabitat types. Our tree reveals extensive cryptic diversity calling any widespread taxa into doubt, and clearly demonstrates that complex multispecies communities of Asterophryinae are ecologically diverse, are numerous, and of ancient origin across New Guinea. We discuss the implications of our phylogeny for explaining the explosive diversification of Asterophryinae as the result of adaptive radiation, niche conservatism, and non-adaptive radiation.

Aim: Variation in body size across animal species underlies most ecological and evolutionary processes shaping local- and large-scale patterns of biodiversity. For well over a century, climatic factors have been regarded as primary sources of natural selection on animal body size, and hypotheses such as Bergmann's rule (the increase of body size with decreasing temperature) have dominated discussions. However, evidence for consistent climatic effects, especially among ectotherms, remains equivocal. Here, we test a range of key hypotheses on climate-driven size evolution in squamate reptiles across several spatial and phylogenetic scales. \ud \ud Location: Global. \ud \ud Time period: Extant.\ud \ud Major taxa studied: Squamates (lizards and snakes).\ud \ud Methods: We quantified the role of temperature, precipitation, seasonality and net primary productivity as drivers of body mass across ca. 95% of extant squamate species (9,733 spp.). We ran spatial autoregressive models of phylogenetically corrected median mass per equal-area grid cell. We ran models globally, across separate continents and for major squamate clades independently. We also performed species-level analyses using phylogenetic generalized least square models and linear regressions of independent contrasts of sister species.\ud \ud Results: Our analyses failed to identify consistent spatial patterns in body size as a function of our climatic predictors. Nearly all continent- and family-level models differed from one another, and species-level models had low explanatory power. \ud \ud Main conclusions: The global distribution of body mass among living squamates varies independently from the variation in multiple components of climate. Our study, the largest in spatial and taxonomic scale conducted to date, reveals that there is little support for a universal, consistent mechanism of climate-driven size evolution within squamates.

Adaptations for efficient performance are expected to shape animal morphology based on selection for microhabitat use and ecological forces. The presence of competitor species is predicted to cause niches to contract and enhance trait divergence. Therefore, increased species richness is expected to lead to greater trait divergence, and to result in reduced overlap and similarity between morphologies of sympatric species. We examined patterns of morphospace occupancy and partitioning in the skink fauna of New Guinea, the world's largest tropical island. Because skink species richness is largely decoupled from elevation in New Guinea, we could examine the effects of both factors (as proxies for competition and abiotic conditions), on morphospace occupancy and partitioning. We measured 1,860 specimens from 79 species of skinks throughout Papua New Guinea, and examined their morphospace occupancy in a spatial context. We calculated, for each assemblage within equal-area cells, the volume of morphospace occupied by all skinks, the mean volume occupied per species, and the mean distance and overlap between all species pairs. We then examined whether these metrics are related to species richness and elevation. Elevation is a stronger predictor of morphospace occupancy than species richness. As elevation increases, intraspecific variation decreases and morphologies become more similar to each other such that overall morphospace occupancy decreases. Highland skinks are, on average, smaller, thinner and shorter limbed than lowland species. We hypothesise that harsh climates in the New Guinea highland habitats impose strong selection on skinks to occupy specific areas of morphospace that facilitate efficient thermoregulation in suboptimal thermal conditions. We conclude that the effect of competition on trait divergence on a community and assemblage scale is eclipsed by abiotic selection pressures in these harsh environments.

New Guinea, the world’s largest and highest tropical island, has a rich but poorly known biota. Papuascincus is a genus of skinks endemic to New Guinea’s mountain regions, comprising two wide-ranging species and two species known only from their type series. The phylogeny of the genus has never been examined and the relationships among its species – as well as between it and closely related taxa – are hitherto unknown. We performed the first large-scale molecular-phylogenetic study of Papuascincus, including sampling across the genus' range in Papua New Guinea. We sequenced three mitochondrial and two nuclear markers from 65 specimens of Papuascincus and reconstructed their phylogenetic relationships. We also performed species-delimitation analyses, estimated divergence times and ancestral biogeography, and examined body-size evolution within the genus. Papuascincus was strongly supported as monophyletic. It began radiating during the mid-Miocene in the area now comprising the Central Cordillera of New Guinea, then dispersed eastward colonising the Papuan Peninsula. We found evidence of extensive cryptic diversity within the genus, with between nine and 20 supported genetic lineages. These were estimated using three methods of species delimitation and predominantly occur in allopatry. Distribution and body-size divergence patterns indicated that character displacement in size took place during the evolutionary history of Papuascincus. We conclude that the genus requires comprehensive taxonomic revision and likely represents a species-rich lineage of montane skinks., This work was supported by BSF grants no. 2012143 to S.M. and A.A., NSF grants no. DEB-0103794 and 0743890 to F.K., and by the Naomi Foundation through the Tel Aviv University GRTF programme grant no. 064181317 to A.S. K.T. and S.C. were supported by grants CGL2015-70390-P and PGC2018-098290-B-I00 (co-funded by FEDER) from the Spanish government.

We trace the taxonomic history of Toxicocalamus, a poorly known genus of primarily vermivorous snakes found only in New Guinea and associated island archipelagos. With only a relatively limited number of specimens to examine, and the distribution of those specimens across many natural history collections, it has been a difficult task to assemble a complete taxonomic assessment of this group. As a consequence, research on these snakes has undergone a series of fits and starts, and we here present the first comprehensive chronology of the genus, beginning with its original description by George Albert Boulenger in 1896. We also describe a new species from the northern versant of the Owen Stanley Range, Oro Province, Papua New Guinea, and we present a series of comparisons that include heretofore underused characteristics, including those of unusual scale patterns, skull details, and tail tip morphology. Defined by the smallest holotype in the genus, the new species is easily differentiated from all other Toxicocalamus by a combination of the following eidonomic characters: fused prefrontal-internasal scute; single preocular, separate, not fused with prefrontal; minute circular, counter-sunk naris in the centre of a large, undivided, nasal scute; paired postoculars; single anterior temporal and paired posterior temporals; six supralabials, with 3rd and 4th supralabial contacting the orbit; dorsal scales in 15-15-15 rows; 235 ventral scales, 35 paired subcaudal scales; paired cloacal scales preceded by paired precloacal scales; and a short, laterally slightly compressed, ‘Ultrocalamus-type’ tail, terminating in a short conical scale. Differences from congeners in skull morphology include a reduced anterior extent of the parasphenoid, termination of the palatine tooth row at the anterior level of the parasphenoid, extent and shape of the premaxilla, shape and size of the prootics, extent and shape of the exoccipitals and occipital condyles, and features of the atlas-axis complex. This is the fifteenth species in the genus Toxicocalamus.