Evolutionary Changes Research Articles

Stabilizing selection in an identified multisensory neuron in blind cavefish

The ability to follow the evolutionary trajectories of specific neuronal cell types has led to major insights into the evolution of the vertebrate brain. Here, we study how cave life in the Mexican tetra ( Astyanax mexicanus ) has affected an identified giant multisensory neuron, the Mauthner neuron (MN). Because this neuron is crucial in driving rapid escapes, the absence of predation risk in the cave forms predicts a massive reduction in this neuron. Moreover, the absence of functional eyes in the A. mexicanus Pachón form predicts an even stronger reduction in the cell’s large ventral dendrite that receives visual inputs in sighted fish species. We succeeded in recording in vivo from this neuron in the blind cavefish and two surface tetra ( A. mexicanus and Astyanax aeneus ), which offers unique chances to simultaneously study evolutionary changes in morphology and function in this giant neuron. In contrast to the predictions, we find that cave life, while sufficient to remove vision, has neither affected the cell's morphology nor its functional properties. This specifically includes the cell's ventral dendrite. Furthermore, cave life did not increase the variance in morphological or functional features. Rather, variability in surface and cave forms was the same, which suggests a complex stabilizing selection in this neuron and a continued role of its ventral dendrite. We found that adult cavefish are potent predators that readily attack smaller fish. So, one of the largely unknown stabilizing factors could be using the MN in such attacks and, in the young fish, escaping them.

The Role of Digital Marketing Technologies in Enhancing Business Process Management

In the many stages of the digital revolution's progress, digitalisation has strong foundations and significant turning points. The word "digit" was derived etymologically from the Latin phrase "digitalis." The practice of counting with fingers and toes numbers lower than ten was commonly referred to by this phrase in the middle of the fifteenth century. Going forward to the 1650's numerical meaning, data processing on computers began in 1938, replacing analogue methods. 1945 marked yet another turning point in the rapid processing of evolutionary changes, before the 1960s saw the emergence of extensive data collection and broadcasting of events. Marketing operates through an integrated method that combines the arts and sciences. The arts create demand, while the sciences assess market potential and the company's ability to meet that need. It is harder to market services than it is to sell items. The field of digital marketing has grown more dynamic and complex. Technology is constantly requiring exceptional upgrades due to its rapid changes, diversified applications, version modifications, and advanced generations. A company's ability and desire to adapt to the evolving form, function, and structure of digital technology is a prerequisite for any stable reliance on it.

Whether niche changes promote the evolution of species: a case study of Paeonia in Asia and North America

Ecological changes have been observed to promote rates of lineage diversification, yet the precise roles of ecological factors, species evolution, and environmental variability in driving species diversity remain research hot spots. The association between ecological change and lineage diversification, particularly with regard to the size of the time scale, remains poorly understood. To explore whether ecological change facilitates species evolution, we focused on the unique family Paeoniaceae, which encompasses both herbaceous and woody taxa, to investigate the evolutionary rates. As a unique family characterized by a single genus of angiosperms and comprising various climatic types, the ecological niche changes of Paeoniaceae are closely associated with the evolution, making it an ideal model for conducting association analysis. In this study, we integrated the molecular fragments and ecological factors to explore the relationship between species evolution and niche changes in Paeoniaceae. The phylogenetic tree revealed that Paeoniaceae forms a sister relationship with Penthoraceae, Haloragidaceae, Iteaceae, Crassulaceae, and Saxifragaceae, constituting an independent clade based on the positive selection of molecular fragments including two protein-coding genes and eight non-coding regions. The divergence time was estimated to be between 102 and 116 Mya (Million years ago). The phylogenetic tree within Paeonia revealed a clear division into three groups: sections of Paeonia, Moutan, and Onaepia with high support values for each branch based on the ten positive selection of molecular fragments. The rapid rate of evolution observed in Paeonia, about 0-5 Mya. In addition, ecological niche modeling showed that the potential distributions for Paeonia expanded from middle Asia to eastern Asia, and from central North America to the Northern part of North America during the Last Glacial Maximum (LGM) to Mid Holocene (MID) period. This suggests that Paeonia continuously adapted to changing ecological environments over time. Compared to the rate of climatic niche divergence and lineage diversification, the ecological niche of Paeonia underwent significant changes during the period of 3-11 Mya, occurring 5 Mya earlier than the period of evolutionary rate change. These findings offer comprehensive insights into the relationship between niche change and the evolution of species, providing valuable perspectives for further ecological cultivation efforts.

Orchid phylogenetics and evolution: history, current status and prospects.

Orchidaceae are one of the two largest families of angiosperms; they exhibit a host of changes -- morphological, ecological and molecular -- that make them excellent candidates for evolutionary study. Such studies are most effectively performed in a phylogenetic context, which provides direction to character change. Understanding of orchid relationships began in the pre-evolutionary classification systems of the 1800's that were based solely on morphology, and now is largely based on genomic analysis. The resulting patterns have been used to update family classification and to test many evolutionary hypotheses in the family. Recent analyses with dense sampling and large numbers of nuclear loci have yielded well-supported trees that have confirmed many longstanding hypotheses and overturned others. They are being used to understand evolutionary change and diversification in the family. These include dating the origination of the family, analysis of change in ecological habit (from terrestrial to epiphytic and back again in some cases), revealing significant plastid genome change in leafless holomycotrophs, studying biogeographic patterns in various parts of the world, and interpreting patterns of fungal associations with orchids. Understanding of orchid relationships has progressed significantly in recent decades, especially since DNA sequence data have been available. These data have contributed to an increasingly refined classification of orchids and the pattern has facilitated many studies on character evolution and diversification in the family. Whole genome studies of the family are just beginning and promise to reveal fine-level details underlying structure and function in these plants, and, when set in a phylogenetic context, provide a much richer understanding of how the family has been so successful in diversification.

Transition Path Sampling Based Free Energy Calculations of Evolution's Effect on Rates in β-Lactamase: The Contributions of Rapid Protein Dynamics to Rate.

β-Lactamases are one of the primary enzymes responsible for antibiotic resistance and have existed for billions of years. The structural differences between a modern class A TEM-1 β-lactamase compared to a sequentially reconstructed Gram-negative bacteria β-lactamase are minor. Despite the similar structures and mechanisms, there are different functions between the two enzymes. We recently identified differences in dynamics effects that result from evolutionary changes that could potentially account for the increase in substrate specificity and catalytic rate. In this study, we used transition path sampling-based calculations of free energies to identify how evolutionary changes found between an ancestral β-lactamase, and its extant counterpart TEM-1 β-lactamase affect rate.

Can human brain connectivity explain verbal working memory?

ABSTRACT The ability of humans to store spoken words in verbal working memory and build extensive vocabularies is believed to stem from evolutionary changes in cortical connectivity across primate species. However, the underlying neurobiological mechanisms remain unclear. Why can humans acquire vast vocabularies, while non-human primates cannot? This study addresses this question using brain-constrained neural networks that realize between-species differences in cortical connectivity. It investigates how these structural differences support the formation of neural representations for spoken words and the emergence of verbal working memory, crucial for human vocabulary building. We develop comparative models of frontotemporal and occipital cortices, reflecting human and non-human primate neuroanatomy. Using meanfield and spiking neural networks, we simulate auditory word recognition and examine verbal working memory function. The “human models”, characterized by denser inter-area connectivity in core language areas, produced larger cell assemblies than the “monkey models”, with specific topographies reflecting semantic properties of the represented words. Crucially, longer-lasting reverberant neural activity was observed in human versus monkey architectures, compatible with robust verbal working memory, a necessary condition for vocabulary building. Our findings offer insights into the structural basis of human-specific symbol learning and verbal working memory, shedding light on humans’ unique capacity for large vocabulary acquisition.

Multimodal signalling in manakins: lack of correlated evolution between acoustic, visual and behavioural traits

Sexual traits, such as visual adornments, sound‐based cues and courtship dances, are frequently displayed in combination as multimodal signals. Some hypotheses propose that different signals trade‐off with each other, potentially due to resource limitations (‘trade‐off’ or transfer hypothesis) or that these develop simultaneously to enhance communication effectiveness (‘joint evolution’ hypothesis). Alternatively, multiple cues may evolve independently to serve distinct functions or convey different information (‘multiple messages’ hypothesis). Here, we explored the interdependence between different signal modalities in manakins (Pipridae), which are known for great interspecific diversity in the degree of elaboration in courtship dance, song and plumage coloration. We also used comparative methods to explore the mode of evolution and the degree of conservatism of these signals. We found that song, plumage coloration and courtship dance evolved independently as there was no correlation between these traits. Song evolution in manakins was attracted to a single optimum and exhibited a weak phylogenetic signal in comparison with those of colour and behavioural diversity. The high support found for the speciational and κ models when analysing the multivariate estimates of trait variability suggests that these signals (especially colour and behaviour attributes) may have evolved in a punctuated manner, with large evolutionary changes at speciation events and minimal subsequent changes along the branches. Our results show that song, colour and dance diversity are each associated (or marginally associated) with different ecological factors, indicating that sexual signals in manakins might convey different information and/or respond to different selection pressures. Larger species and those with lower dispersal capacity tend to exhibit higher colour richness, which in turn differed among lek categories, being higher in species with ‘classic’ leks and lower in non‐lekking species. Overall, the present study supports the idea that correlation between signal modalities does not constitute a widespread pattern in songbirds.

Ultrafast Evolution of Bacterial Antimicrobial Resistance by Picoliter-Scale Centrifugal Microfluidics.

Experimental evolution is a powerful approach for scrutinizing and dissecting the development of antimicrobial resistance; nevertheless, it typically demands an extended duration to detect evolutionary changes. Here, a centrifugal microfluidics system is designed to accelerate the process. Through a simple step of on-chip centrifugation, a highly condensed bacterial matrix of ∼1012 cells/mL at the enrichment tip of the chip channel is derived, enabling bacteria encapsulated to survive in antimicrobial concentrations several times higher than the minimum inhibitory concentration (MIC) and rapidly develop resistance in the first 10 h. After 48 h of on-chip evolution, the E. coli strain demonstrated a 64 to 128-fold reduction in sensitivity to disinfectants (triclosan) as well as antibiotics (ciprofloxacin and amikacin), a rate substantially swifter compared to conventional continuous inoculation-based experimental evolution. The speed and simplicity of this microfluidic system suggest its broad application for uncovering resistance mechanisms and identifying targets of biocides and antibiotics.

The skull of Hapalodectes (Hapalodectidae, Mesonychia) from the Paleocene of Mongolia.

The incomplete skull of Hapalodectes (Hapalodectidae, Mesonychia) is described from the Upper Paleocene Naran Member of the Naran Bulak Formation of the Khaychin-Ula 2 locality in the Bugin Tsav Basin in the south of Mongolia. This is the first discovery of the skull of a Paleocene member of the genus. The skull corresponds in size and dental occlusion to the species H. dux Lopatin, 2001, previously known only from a lower jaw from the Upper Paleocene Zhigden Member of the Naran Bulak Formation of the Tsagan-Khushu locality in the Nemegt Basin. In the structure of the facial part of the skull, H. dux exhibits features shared with Mesonychidae, namely the significant participation of the lacrimal and jugal in the preorbital region. The upper molars of H. dux were found to have distinct conules (a first for Hapalodectidae). The evolutionary changes in the structure of the upper molars of Hapalodectes (disappearance of the conules, decrease of the metacone, and narrowing of the lingual lobe) are determined. They were correlated with the transformations of the lower molars (reduction of the metaconid, protocristid, and entoconid, transverse compression of the trigonid and talonid) and together with them were aimed at enhancing the shearing action of the longitudinal trenchant blades of the posterior part of the dentitions.

De Novo Sequencing of Drymaria villosa and Comparative Analysis of Plastome in Caryophyllaceae Across 23 Species.

Plant plastome are well studied due to their essential roles in photosynthesis and plant development. Comparative studies among plastome of closely related genera or families are limited, hindering our understanding of evolutionary changes and adaptation. This study presents a comparative analysis of 23 Caryophyllaceae plastome revealing a dynamic interplay of conserved and variable features. The genome size exhibited a moderate coefficient of variation (CV) of 2.58%. The large single-copy (LSC) and small single-copy (SSC) regions were highly conserved, with CVs of 2.55% and 2.00%, respectively. In contrast, the inverted repeat (IR) regions displayed greater variability, with a CV of 4.23%, indicating dynamic evolutionary processes. Exon counts varied significantly (CV 17.20%), while intron counts showed some variability (CV 7.79%), reflecting diverse gene structures. Coding sequences had moderate variability (CV 3.67%), while non-coding sequences varied more (CV 5.05%). tRNA counts were slightly variable (CV 2.67%), and GC content was notably consistent (CV 0.40%). This study includes the newly sequenced plastome of Drymaria villosa (GenBank accession OR790517), confirming its placement within Caryophyllaceae with significant diversification through phylogenetic analysis. Correlations (> 0.6) among plastome components and genome size reflect their tight evolutionary linkage, enhancing our understanding of plastome evolution in Caryophyllaceae and aiding future investigations into the ecological and medicinal potential of D. villosa and related species.

Evaluation of population genetics of Moringa oleifera Provenances from Coastal Kenya using Single Nucleotide Polymorphism (SNPs) markers

Population genetics analysis is a prerequisite to understanding how and why genotypes and allele frequencies and change over time between and within populations. Consequently, it offers insight into the process of evolutionary change and makes it possible to map variants linked to traits that differ among populations. In the present study, Single Nucleotide Polymorphisms (SNPs) markers were utilized to study the genetic characterization of 17 provenances from the Coast region of Kenya. 164 genotypes of Moringa oleifera were selected from 17 populations and genome sequencing undertaken utilizing genotyping by sequencing (GBS). Identification of polymorphisms (SNP Calling) in the selected genotypes and population genetic studies were carried out. SNP calling was done by Illumina’s SNP caller algorithm in the CASAVA software. 20,921 SNPs were called with an average call rate of 0.82. Average polymorphsm content (PIC) for the SNPs was 0.24 and reproducibility was 0.98. A phenetic tree was constructed using a neighbor-joining approach using DArT R. For the population genetics analysis, F statistic (Fst) utilising the functions StAMPP package in DArT R was performed whereby Gede and Samburu exhibited the least heterozygosity/correlation with a value of 0.0003 whereas Pwani University and Samburu had the highest correlation of genes at 0.37. Euclidean was used as a measure distance, and the average distance between the populations was 33.024. The molecular variance analysis (AMOVA) described a lower, 2.55%, variation within the population and 2.73% among the populations. The high similarity between the genotypes could be attributed to the Moringa plants in the various provenances having the same ancestry. This study may help identify links between gene allelic forms and phenotypes, allowing the alleles to be connected to desired characteristics such as rapid growth and high yield (functional analysis), because of the high frequency of SNPs and their role as a source of allele variations.

Spore morphology of Adiantum species from the Indian sub-continent using LM and FESEM: Palaeoecological analysis and Phylogenetic delineation

ABSTRACT The palynology of fern spores has proven to be an immensely useful tool in the identification and phylogenetic characterization of various fern taxa. A diverse range of spore morphologies have been studied yet, nevertheless, the investigation of 21 species of Adiantum under Light Microscopy (LM) and Field Emission Electron Microscopy (FESEM) is a maiden attempt from India to develop a spore micro-morphometric dataset that complies with taxonomic traits, fossil counterparts, and evolutionary changes. All the studied spores of Adiantum species possess significant differences in lete character (aperture, primary character); exospores ornamentation (secondary character); and spore shape (tertiary character). The sexine pattern varies from psilate to verrucate, scabrate to granulate, and rugulate to fossulate (eurypalynous type). The perine is a characteristic feature of the fern spores as evident in A. myriosorum, A. zollingeri, and A. philippense, suggesting the diversity among different Adiantum spores. The multivariate statistical analysis indicates three major clusters based on spore morphological characteristics. The evolutionary outcome of this micro-morphometric analysis showed that the spore of A. formosum is composed of the most primitive characters (such as unconstricted lete arm, smooth exospore, and non-perinate sclerine), whereas the spores of A. zollingeri and A. myriosorum comprised advanced characters (such as constricted lete arms, rugulate exospores, and perinate sclerine). This extensive spore morphological examination would provide a comprehensive dataset for the identification of fossil spores (up to the species level) and taxonomic characterization of Adiantum species in India and its comparison with other species growing around the world.

Linking phylogenetic niche conservatism in bacterial communities in sorghum root compartments revealed by the Hongyingzi cultivar.

The root system harbours complex bacterial communities, which are critical for plant growth and health. Significant differences exist between bacterial communities in the root compartments; however, limited reports have explored their phylogenetic composition and niche conservatism in the root system of sorghum. We used the sorghum Hongyingzi cultivar as test plant, and applied 16S rRNA high-throughput sequencing and various statistical approaches. Phylogenetic composition of bacterial communities in root compartments were primarily driven by closely related species with similar environmental adaptations. We also found evidence of phylogenetic niche conservatism in bacterial communities for edaphic factors in the various root compartments, with pH and available N playing essential roles in shaping community composition. Environmental threshold analysis revealed threshold ranges of dominant taxa for pH and available N, indicating wider adaptive thresholds for more abundant taxa. Reconstruction of ancestral states suggested evolutionary changes in adaptability of certain bacterial taxa to edaphic factors, suggesting a shift towards slightly acidic, high N environments and reflecting the prolonged mutual interaction between bacteria and plants in cultivated soils. These findings enhance our understanding of environmental responses and evolutionary dynamics of root-associated microbiota in young sorghum plants and provide novel insights into ecological adaptations, shedding light on their responses to environmental factors. Our study contributes to a better understanding of the ecological dynamics of root-associated microbiota and offers analytical pathways for exploring the nutritional regulation of root microbiota.

The diversity of glycan chains in jellyfish mucin of three Cubozoan species: the contrast in molecular evolution rates of the peptide chain and Glycans.

The O-glycan composition of jellyfish (JF) mucin (qniumucin: Q-mucin) extracted from three Cubozoan species was studied after the optimization of the purification protocol. Application of a stepwise gradient of ionic strength to anion exchange chromatography (AEXC) was effective for isolating Q-mucin from coexisting impurities. In the three species, the amino acid sequence of the tandem repeat (TR) region in Q-mucin in all three Cubozoans seemed to remain the same as that in all Scyphozoans, although their glycan chains seemed to exhibit clear diversity. In particular, the amounts of acidic moieties on the glycan chains of Q-mucin from the Cubozoans markedly varied even in these genetically close species. In two of the three Cubozoan species, the fraction of disaccharides was large, showing a sharp contrast to that of the glycans of Q-mucin in Scyphozoans. This study also indicates that the simple sequence of TR commonly inherited in all Cubozoan and Scyphozoan JF species after the long term of evolution over 500Myears. According to this research, the glycans and the TR of mucin-type glycoproteins (MTGPs), forming a hierarchical structure, appear to complement each other in the evolutionary changes because the time required for their hereditary conversion is considerably different. The cooperation of these mechanisms is a strategy to achieve the contradictory functions of biosystems, namely species conservation and diversity acquisition.

Shared environmental similarity between relatives influences heritability of reproductive timing in wild great tits.

Intraspecific variation is necessary for evolutionary change and population resilience, but the extent to which it contributes to either depends on the causes of this variation. Understanding the causes of individual variation in traits involved with reproductive timing is important in the face of environmental change, especially in systems where reproduction must coincide with seasonal resource availability. However, separating the genetic and environmental causes of variation is not straightforward, and there has been limited consideration of how small-scale environmental effects might lead to similarity between individuals that occupy similar environments, potentially biasing estimates of genetic heritability. In ecological systems, environments are often complex in spatial structure, and it may therefore be important to account for similarities in the environments experienced by individuals within a population beyond considering spatial distances alone. Here, we construct multi-matrix quantitative genetic animal models using over 11,000 breeding records (spanning 35 generations) of individually-marked great tits (Parus major) and information about breeding proximity and habitat characteristics to quantify the drivers of variability in two key seasonal reproductive timing traits. We show that the environment experienced by related individuals explains around a fifth of the variation seen in reproductive timing, and accounting for this leads to decreased estimates of heritability. Our results thus demonstrate that environmental sharing between relatives can strongly affect estimates of heritability and therefore alter our expectations of the evolutionary response to selection.

Adaptation to different temperatures results in wing size divergence of the invading species Drosophila nasuta (Diptera: Drosophilidae) in Brazil.

Invasive species threaten biodiversity on a global scale. The success of invasions depends on the species' adaptation to the different environmental conditions of new territories. Studies show that invasive insects present evolutionary changes in wing morphology in areas they are introduced to in response to abiotic conditions. In the last decade, the Asian Drosophila nasuta fly invaded and spread widely throughout Brazil. This insect has preferences for conserved environments and is related to the likely reduction in the abundance of native drosophilids in the Atlantic Forest. Ecological niche modelling analyses showed that rainfall and temperature are the main factors which delimit the geographic distribution of this species. Herein, we verified the existence of significant differences in the wing sizes of D. nasuta in Brazil and evaluated the influence of abiotic factors (rainfall and temperature) on the observed patterns. We conducted 11 measurements on the right-side wings of 240 D. nasuta males collected in the Amazon Forest, Caatinga, Cerrado and Atlantic Forest. Statistical analyses revealed the existence of two groups: one with larger wings, which brought together samples from locations with the lowest temperatures; and one with smaller wings, which corresponded to places with a hotter climate. One explanation for this result is the fact that large wings favour greater heat capture by flies in colder climates, increasing their survival chances in these environments. These rapid evolutionary changes in D. nasuta in this first decade of invasion in Brazil reveal the enormous adaptive potential of this species in this megadiverse country.

Genomic Vulnerability to Climate Change of an Australian Migratory Freshwater Fish, the Golden Perch (Macquaria ambigua).

Genomic vulnerability is a measure of how much evolutionary change is required for a population to maintain optimal genotype-environment associations under projected climates. Aquatic species, and in particular migratory ectotherms, are largely underrepresented in studies of genomic vulnerability. Such species might be well equipped for tracking suitable habitat and spreading diversity that could promote adaptation to future climates. We characterised range-wide genomic diversity and genomic vulnerability in the migratory and fisheries-important golden perch (Macquaria ambigua) from Australia's expansive Murray-Darling Basin (MDB). The MDB has a steep hydroclimatic gradient and is one of the world's most variable regions in terms of climate and streamflow. Golden perch are threatened by fragmentation and obstruction of waterways, alteration of flow regimes, and a progressively hotter and drying climate. We gathered a genomic dataset of 1049 individuals from 186 MDB localities. Despite high range-wide gene flow, golden perch in the warmer, northern catchments had higher predicted vulnerability than those in the cooler, southern catchments. A new cross-validation approach showed that these predictions were insensitive to the exclusion of individual catchments. The results raise concern for populations at warm range edges, which may already be close to their thermal limits. However, a population with functional variants beneficial for climate adaptation found in the most arid and hydrologically variable catchment was predicted to be less vulnerable. Native fish management plans, such as captive breeding and stocking, should consider spatial variation in genomic vulnerability to improve conservation outcomes under climate change, even for dispersive species with high connectivity.

Dedicated developmental programing for group-supporting behaviors in eusocial honeybees.

The evolutionary changes from solitary to eusocial living in vertebrates and invertebrates are associated with the diversification of social interactions and the development of queen and worker castes. Despite strong innate patterns, our understanding of the mechanisms manifesting these sophisticated behaviors is still rudimentary. Here, we show that doublesex (dsx) manifests group-supporting behaviors in the honeybee (Apis mellifera) worker caste. Computer-based individual behavioral tracking of worker bees with biallelic stop mutations in colonies revealed that the dsx gene is required for the rate and duration of group-supporting behavior that scales the relationship between bees and their work. General sensorimotor functions remained unaffected. Unexpectedly, unlike in other insects, the dsx gene is required for the neuronal wiring of the mushroom body in which the gene is spatially restricted expressed. Together, our study establishes dedicated programming for group-supporting behaviors and provides insight into the connection between development in the neuronal circuitry and behaviors regulating the formation of a eusocial society.

Investigation of the Development and Evolution of the Mammalian Cerebrum using Gyrencephalic Ferrets

Mammalian brains have evolved a neocortex, which has diverged in size and morphology in different species over the course of evolution. In some mammals, a substantial increase in the number of neurons and glial cells resulted in the expansion and folding of the cerebrum, and it is believed that these evolutionary changes contributed to the acquisition of higher cognitive abilities in mammals. However, their underlying molecular and cellular mechanisms remain insufficiently elucidated. A major difficulty in addressing these mechanisms stemmed from the lack of appropriate animal models, as conventional experimental animals such as mice and rats have small brains without structurally obvious folds. Therefore, researchers including us have focused on using ferrets instead of mice and rats. Ferrets are domesticated carnivorous mammals with a gyrencephalic cerebrum, and, notably, they are amenable to genetic manipulations including in utero electroporation to knock out genes in the cerebrum. In this review, we highlight recent research into the mechanisms underlying the development and evolution of cortical folds using ferrets.

Rapid Evolution of Host Repertoire and Geographic Range in a Young and Diverse Genus of Montane Butterflies.

Evolutionary changes in geographic distribution and larval host plants may promote the rapid diversification of montane insects, but this scenario has been rarely investigated. We studied rapid radiation of the butterfly genus Colias, which has diversified in mountain ecosystems in Eurasia, Africa, and the Americas. Based on a dataset of 150 nuclear protein-coding genetic loci and mitochondrial genomes, we constructed a time-calibrated phylogenetic tree of Colias species with broad taxon sampling. We then inferred their ancestral geographic ranges, historical diversification rates, and the evolution of host use. We found that the most recent common ancestor of Colias was likely geographically widespread and originated ~3.5 Ma. The group subsequently diversified in different regions across the world, often in tandem with geographic expansion events. No aspect of elevation was found to have a direct effect on diversification. The genus underwent a burst of diversification soon after the divergence of the Neotropical lineage, followed by an exponential decline in diversification rate toward the present. The ancestral host repertoire included the legume genera Astragalus and Trifolium but later expanded to include a wide range of Fabaceae genera and plants in more distantly related families, punctuated with periods of host range expansion and contraction. We suggest that the widespread distribution of the ancestor of all extant Colias lineages set the stage for diversification by isolation of populations that locally adapted to the various different environments they encountered, including different host plants. In this scenario, elevation is not the main driver but might have accelerated diversification by isolating populations.