Animal phenotypes evolve and diverge as a result of differing selective pressures and drift. These processes leave unique signatures in patterns of trait evolution, impacting the tempo and mode of morphological macroevolution. While there is a broad understanding of the history of some organismal traits (e.g., body size), there is little consensus about the evolutionary mode of most others. This includes the relative contribution of prolonged (Darwinian gradualist) and episodic (Simpsonian jump) changes toward the evolution of novel morphologies. Here, we use new exon-capture and linear morphological datasets to investigate the tempo and mode of morphological evolution in Australo-Melanesian Tiliquini skinks. We generate a well-supported time-calibrated phylogenomic tree from ∼400 nuclear markers for more than 100 specimens, including undescribed diversity, and provide unprecedented resolution of the rapid Miocene diversification of these lizards. By collecting a morphological dataset that encompasses the lizard body plan (19 traits across the head, body, limb, and tail), we are able to identify that most traits evolve conservatively, but infrequent evolutionary bursts result in morphological novelty. These phenotypic discontinuities occur via rapid rate increases along individual branches, inconsistent with both gradualistic and punctuated equilibrial evolutionary modes. Instead, this \"punctuated gradualism\" has resulted in the rapid evolution of blue-tongued giants and armored dwarves in the ∼20 million years since colonizing Australia. These results outline the evolutionary pathway toward new morphologies and highlight the heterogeneity of evolutionary tempo and mode, even within individual traits.

The morphological symmetry-retaining and symmetry-breaking of single crystals of the γ-cyclodextrin metal-organic framework have been achieved via introducing lower symmetric β-cyclodextrins and α-cyclodextrins, respectively. β-cyclodextrins led to a morphological evolution with retained symmetry from cubic to rhombic dodecahedra, while α-cyclodextrins resulted in the original cubic crystal missing a vertex angle presenting symmetry-breaking behavior. The crystal structures of rhombic dodecahedra and angle-deficient crystals were confirmed through X-ray crystallography, and the mechanisms underlying the morphological transformation evolution were further analyzed. Our work not only provides a rare case realizing two different paths of morphological evolution in one system, but also encourages future efforts towards the evolution of artificial crystal systems in a natural way.

The fern independent gametophytes that can maintain populations by vegetative reproduction without conspecific sporophytes have been considered an unusual phenomenon found in some epiphytic or epilithic species of Hymenophyllaceae, Pteridaceae, Lomariopsidaceae, and Polypodiaceae. By chance, the discovery of mysterious strap-like gametophytes on Izu-Oshima Island, Japan, has led to the hypothesis that Hymenasplenium murakami-hatanakae, a fern species belonging to Aspleniaceae, can also form independent gametophytes. Our investigation revealed gametophyte populations of H. murakami-hatanakae on three islands in the Izu Islands. Based on chloroplast DNA analysis of the gametophyte and sporophyte populations, the gametophytes were found to be maintained by vegetative reproduction without a new supply of spores from sporophytes. A comparison of the surrounding vegetation at the collection sites showed that environmental factors such as light and humidity may influence the maintenance of gametophyte populations. These results clearly show that H. murakami-hatanakae is one of the ferns capable of forming independent gametophytes. This is the first report of independent gametophytes from the suborder Aspleniineae (eupolypod II). The discovery of the independent gametophyte within a phylogenetic lineage previously thought not to form independent gametophytes will provide important insights into the morphological and functional evolution of gametophytes in ferns.

Sexes often have differing fitness optima, potentially generating intra-locus sexual conflict, as each sex bears a genetic \"load\" of alleles beneficial to the other sex. One strategy to evaluate conflict in the genome is to artificially select populations discordantly against established sexual dimorphism (SD), reintroducing attenuated conflict. We investigate a long-term artificial selection experiment reversing sexual size dimorphism in Drosophila melanogaster during ~350 generations of sexually discordant selection. We explore morphological and genomic changes to identify loci under selection between the sexes in discordantly and concordantly size-selected treatments. Despite substantial changes to overall size, concordant selection maintained ancestral SD. However, discordant selection altered size dimorphism in a trait-specific manner. We observe multiple possible soft selective sweeps in the genome, with size-related genes showing signs of selection. Patterns of genomic differentiation between the sexes within lineages identified potential sites maintained by sexual conflict. One discordant selected lineage shows a pattern of elevated genomic differentiation between males and females on chromosome 3L, consistent with the maintenance of sexual conflict. Our results suggest visible signs of conflict and differentially segregating alleles between the sexes due to discordant selection.

The colonization of a novel geographic area is a classic source of ecological opportunity. Likewise, complex microhabitats are thought to promote biodiversity. We sought to reconcile these two predictions when they are naturally opposing outcomes. We assess the macroevolutionary consequences of an ancestral shift from benthic to pelagic microhabitat zones on rates of speciation and phenotypic evolution in North American minnows. Pelagic species have more similar phenotypes and slower rates of phenotypic evolution, but faster speciation rates, than benthic species. These are likely two independent, opposing responses to specialization along the benthic-pelagic axis, as rates of phenotypic evolution and speciation are not directly correlated. The pelagic zone is more structurally homogenous and offers less ecological opportunity, acting as an ecological dead end for minnows. In contrast, pelagic species may be more mobile and prone to dispersal and subsequent geographic isolation and, consequently, experience elevated instances of allopatric speciation. Microhabitat shifts can have decoupled effects on different dimensions of biodiversity, highlighting the need for nuance when interpreting the macroevolutionary consequences of ecological opportunity.

Modular architecture of traits in complex organisms can be important for morphological evolution at micro- and sometimes macroevolutionary scales as it may influence the tempo and direction of changes to groups of traits that are essential for particular functions, including food acquisition and processing. We tested several distinct hypotheses about craniofacial modularity in the hominine skull in relation to feeding biomechanics.
First, we formulated hypothesized functional modules for craniofacial traits reflecting specific demands of feeding biomechanics (e.g., masseter leverage/gape or tooth crown mechanics) in Homo sapiens, Pan troglodytes, and Gorilla gorilla. Then, the pattern and strength of modular signal was quantified by the covariance ratio coefficient and compared across groups using covariance ratio effect size. Hierarchical clustering analysis was then conducted to examine whether a priori-defined functional modules correspond to empirically recovered clusters.
There was statistical support for most a priori-defined functional modules in the cranium and half of the functional modules in the mandible. Modularity signal was similar in the cranium and mandible, and across the three taxa. Despite a similar strength of modularity, the empirically recovered clusters do not map perfectly onto our priori functional modules, indicating that further work is needed to refine our hypothesized functional modules.
The results suggest that modular structure of traits in association with feeding biomechanics were mostly shared with humans and the two African apes. Thus, conserved patterns of functional modularity may have facilitated evolutionary changes to the skull during human evolution.

The evolution of carnivorous pitcher traps across multiple angiosperm lineages represents a classic example of morphological convergence. Nevertheless, no comparative study to-date has examined pitcher evolution from a quantitative morphometric perspective.
In the present study, we used comparative morphometric approaches to quantify the shape space occupied by Heliamphora pitchers and to trace evolutionary trajectories through this space to examine patterns of divergence and convergence within the genus. We also investigated pitcher development, and, how the packing of pitchers is affected by crowding, a common condition in their natural environments.
Our results showed that Heliamphora pitchers have diverged along three main axes in morphospace: (1) pitcher curvature; (2) nectar spoon elaboration; and (3) pitcher stoutness. Both curvature and stoutness are correlated with pitcher size, suggesting structural constraints in pitcher morphological evolution. Among the four traits (curvature, spoon elaboration, stoutness, and size), all but curvature lacked phylogenetic signal and showed marked convergence across the phylogeny. We also observed tighter packing of pitchers in crowded conditions, and this effect was most pronounced in curved, slender pitchers.
Overall, our study demonstrates that diversification and convergent evolution of carnivory-related traits extends to finer evolutionary timescales, reinforcing the notion that ecological specialization may not necessarily be an evolutionary dead end.
食虫植物的瓶状捕虫器在不同被子植物谱系中的演化是形态趋同进化的经典案例。然而, 迄今为止还没有研究使用系统发育比较分析法与计量方法来研究瓶状捕虫器的演化。本研究使用了上述手段来研究南美沼泽瓶子草 (Heliamphora) 的瓶状捕虫器是如何占据形态空间, 并在捕虫器的形态空间内追踪它们的演化轨迹, 以研究沼泽瓶子草属捕虫器的趋异与趋同的演化模式。同时, 本研究还探讨了沼泽瓶子草属植株 (捕虫瓶) 的发育模式, 特别是在沼泽瓶子草在原生地的发育是如何受到种群密度过高 (拥挤) 的影响。本研究的结果表明, 沼泽瓶子草属捕虫瓶在形态空间里沿着三个主要形态轴分化:捕虫瓶的弯曲度、蜜匙的精细程度和捕虫瓶的粗壮程度。捕虫瓶的弯曲度和粗壮度均与瓶子的大小相关, 表明捕虫瓶在形态进化中存在结构约束。在这四个形态特征中 (捕虫瓶曲率、蜜匙精细程度、捕虫瓶粗壮度与大小), 除了捕虫瓶曲率, 其他的形态特征都没有显示系统发育信号。在南美沼泽瓶子草属的进化中, 蜜匙精细程度、捕虫瓶粗壮度与大小都显示了趋同演化。本研究还阐明了瓶子草植株在拥挤条件下, 捕虫瓶会更加紧密地排列, 而且这种效应在有着弯曲、细长的捕虫瓶的物种中最为显著。总体来说, 本研究显示与食肉有关的特征的趋异和趋同演化发生在更微观的时间尺度上, 也表明了生态专化或许并不是生物进化的死胡同。.

Iridescent ultraviolet (IUV) patterns on pierid butterfly wings are phenotypic adaptations commonly used as sexual signals, generated by scales with ultrastructural modifications. Pierid IUV patterns are sexually dichromatic, with reduced size in females, where conspicuous sexual signaling balances courtship against ecological predation. There have been no phylogenetic reconstructions of IUV within Pieridae and little morphological characterization of phenotypic diversity. Our genus-wide characterization of IUV revealed the uniform similarity of stacked lamellar ridges on the dorsal surface of cover scales. We tested a hypothesis of single versus multiple origins by reconstructing a phylogeny of 534 species (~43.2% described species), with all genera represented, and a trait matrix of 734 species (~59.4%) screened for IUV. A single, early dimorphic origin of IUV followed by several losses and gains received strong support, concluding that IUV patterns and structural coloration are old traits. Collectively, these results support the homology of IUV scales and patterns that diversified within several lineages, suggesting an interplay between female-mediated sexual selection and ecological predatory selection.

Determining the link between genomic and phenotypic change is a fundamental goal in evolutionary biology. Insights into this link can be gained by using a phylogenetic approach to test for correlations between rates of molecular and morphological evolution. However, there has been persistent uncertainty about the relationship between these rates, partly because conflicting results have been obtained using various methods that have not been examined in detail. We carried out a simulation study to evaluate the performance of 5 statistical methods for detecting correlated rates of evolution. Our simulations explored the evolution of molecular sequences and morphological characters under a range of conditions. Of the methods tested, Bayesian relaxed-clock estimation of branch rates was able to detect correlated rates of evolution correctly in the largest number of cases. This was followed by correlations of root-to-tip distances, Bayesian model selection, independent sister-pairs contrasts, and likelihood-based model selection. As expected, the power to detect correlated rates increased with the amount of data, both in terms of tree size and number of morphological characters. Likewise, greater among-lineage rate variation in the data led to improved performance of all 5 methods, particularly for Bayesian relaxed-clock analysis when the rate model was mismatched. We then applied these methods to a data set from flowering plants and did not find evidence of a correlation in evolutionary rates between genomic data and morphological characters. The results of our study have practical implications for phylogenetic analyses of combined molecular and morphological data sets, and highlight the conditions under which the links between genomic and phenotypic rates of evolution can be evaluated quantitatively.

Quantifying and characterizing the pattern of trait covariances is crucial for understanding how population-level patterns of integration might constrain or facilitate craniofacial evolution related to the feeding system. This study addresses an important gap in our knowledge by investigating magnitudes and patterns of morphological integration of biomechanically informative traits in the skulls of Homo sapiens, Pan troglodytes, and Gorilla gorilla. We predicted a lower magnitude of integration among human biomechanical traits since humans eat a softer, less biomechanically challenging diet than apes. Indeed, compared to African apes, the magnitudes of integration were lower in H. sapiens skulls for form data (raw dimensions) but were similar or higher for shape data (raw dimensions scaled by geometric mean). Patterns of morphological integration were generally similar, but not identical, across the three species, particularly for the form data compared to the shape data. Traits that load heavily on the primary axis of variation in morphospace are generally associated with size and/or shape of the temporalis and masseter muscles and with dimensions related to the constrained lever model of jaw biomechanics. Given the conserved nature of morphological integration, skull adaptations for food processing in African apes and humans may have been constrained to occur along certain paths of high evolvability. The conserved pattern of functional integration also indicates that extant hominine species can operate as reasonable analogues for extinct hominins in studies that require population-level patterns of trait variance/covariance.