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What happens when organisms actively modify their environment? Clarifying the role of construction behavior on a macroevolutionary scale is crucial to interpreting phenotypic evolution. Spiders, an extremely successful group of animals exhibiting a wide variety of functional, morphological, and behavioral diversity, are ideal candidates to test whether animal behaviors are related to their phenotypic evolution. Herein, we reconstructed the phylogenomic relationships of 303 spiders covering 105 families with 99 newly developed molecular markers that universally apply across Araneae, and explicitly tested the potential link between construction behavior and somatic evolution based on extensive morphological data from 3,342 extant species and 682 fossil species. Our dated molecular phylogeny provides the backbone for analyses, revealing the behavioral and ecological processes behind these spiders’ morphological adaptations. Evolutionary model analyses showed the artifacts constructed by spiders, especially the suspending webs, expand the spider’s ability to inhabit different habitats. These artifacts have more substantial impacts on their somatic traits than habitats and promote different trajectories of morphological evolution. Specifically, for spiders, silk-lined burrowing produced larger bodies, relatively shorter legs, and longer patellae, while web-building produced smaller bodies, relatively longer legs, and shorter patellae, and hunting promoted an intermediate morphological size. Molecular convergence analysis showed that genes related to morphogenesis or response to stimulus and stress are enriched in spiders with construction behavior. Our study demonstrated that the construction behavior of an animal plays a crucial role in determining the direction and intensity of the selection pressure imposed on it and provides strong evidence that construction behaviors are associated with phenotypic evolution on macroevolutionary timescales. [Araneae; body size; habitat change; molecular marker; leg length; phylogenomics.]

Biological migrations between India and Southeast (SE) Asia provide an ideal system for exploring the effects of geology and climate on species ranges. Geologists have confirmed that the direct collision between India and Eurasia occurred in the Early Eocene, but most migrations occurred between the Indian subcontinent and SE Asia rather than the former and the southern margin of Eurasia. To explain this seemingly paradoxical disconnect between the routes of plate movement and biological migration, we studied the evolutionary history of the tropical spider family Ochyroceratidae based on 101 globally distributed species. We infer a robust dated phylogeny using both transcriptomic data and a data set of classical markers and relate these to biogeographic and climatic analyses. Our results indicate that the monophyly of Ochyroceratidae is strongly supported, and the divergence times suggest a Cretaceous Gondwanan origin of the family. Reconstructed biogeographic histories support a dispersal event from the Indian subcontinent to islands of SE Asia 55–38 Ma. Climatic analyses and the fossil record reveal that ochyroceratids are characterized by a high degree of tropical niche conservatism, and that the ancestor of the Indian and SE Asian clades originated in very warm, wet environments. Early Eocene tropical, perhumid climates in India, and SE Asia may have facilitated ochyroceratid migration, whereas the dry or seasonal climate extending from the eastern coast of China to Central Asia may have acted as a barrier, preventing dispersal. Our analyses suggest that climate plays a more important role than geology in biological migration from the Indian subcontinent to SE Asia, providing new insights into the Indian–Asian biogeographic link. [Biogeography; ecology; geological connections; macroevolution; paleoclimate.]

Evolutionary biology has long been concerned with how changing environments affect and drive the spatiotemporal development of organisms. Coelotine spiders (Agelenidae: Coelotinae) are common species in the temperate and subtropical areas of the Northern Hemisphere. Their long evolutionary history and the extremely imbalanced distribution of species richness suggest that Eurasian environments, especially since the Cenozoic, are the drivers of their diversification. We use phylogenetics, molecular dating, ancestral area reconstructions, diversity, and ecological niche analyses to investigate the spatiotemporal evolution of 286 coelotine species from throughout the region. Based on eight genes (6.5 kb) and 2323 de novo DNA sequences, analyses suggest an Eocene South China origin for them. Most extant, widespread species belong to the southern (SCG) or northern (NCG) clades. The origin of coelotine spiders appears to associate with either the Paleocene-Eocene Thermal Maximum or the hot period in early Eocene. Tibetan uplifting events influenced the current diversity patterns of coelotines. The origin of SCG lies outside of the Tibetan Plateau. Uplifting in the southeastern area of the plateau blocked dispersal since the Late Eocene. Continuous orogenesis appears to have created localized vicariant events, which drove rapid radiation in SCG. North-central Tibet is the likely location of origin for NCG and many lineages likely experienced extinction owing to uplifting since early Oligocene. Their evolutionary histories correspond with recent geological evidence that high-elevation orographical features existed in the Tibetan region as early as 40-35 Ma. Our discoveries may be the first empirical evidence that links the evolution of organisms to the Eocene-Oligocene uplifting of the Tibetan Plateau. [Tibet; biogeography; ecology; molecular clock; diversification.].

DNA barcoding as a method for species identification is rapidly increasing in popularity. However, there are still relatively few rigorous methodological tests of DNA barcoding. Current distance-based methods are frequently criticized for treating the nearest neighbor as the closest relative via a raw similarity score, lacking an objective set of criteria to delineate taxa, or for being incongruent with classical character-based taxonomy. Here, we propose an artificial intelligence-based approach - inferring species membership via DNA barcoding with back-propagation neural networks (named BP-based species identification) - as a new advance to the spectrum of available methods. We demonstrate the value of this approach with simulated data sets representing different levels of sequence variation under coalescent simulations with various evolutionary models, as well as with two empirical data sets of COI sequences from East Asian ground beetles (Carabidae) and Costa Rican skipper butterflies. With a 630-to 690-bp fragment of the COI gene, we identified 97.50% of 80 unknown sequences of ground beetles, 95.63%, 96.10%, and 100% of 275, 205, and 9 unknown sequences of the neotropical skipper butterfly to their correct species, respectively. Our simulation studies indicate that the success rates of species identification depend on the divergence of sequences, the length of sequences, and the number of reference sequences. Particularly in cases involving incomplete lineage sorting, this new BP-based method appears to be superior to commonly used methods for DNA-based species identification.