Cyclocephaline scarabs, the second largest tribe of rhinoceros beetles, are important pollinators of early‐diverging angiosperm families in the tropics. The evolutionary history of cyclocephaline genera is poorly resolved and several genera are thought to be nonmonophyletic. We assess the monophyly of Mimeoma C asey, a group of N eotropical palm‐feeding scarabs, and its relationship to Cyclocephala with a phylogenetic analysis of 2899 bp of DNA sequence data and 18 morphological characters. All five species of Mimeoma were included in analyses along with species of Cyclocephala D ejean, Dyscinetus H arold and Tomarus E richson as outgroup taxa. Nearly complete 28S , 12S and CO1 data were collected from 26 of 29 specimens, of which 16 samples were pinned, museum specimens. 28S data strongly support a nonmonophyletic Mimeoma ; mitochondrial data ( CO1 and 12S ) suggest that Mimeoma species are nested within an apical clade of other Cyclocephala species; combined molecular and morphological data identify two strongly supported clades of Mimeoma species but do not support their sister relationship. Combined data show that Mimeoma species are nested within Cyclocephala , thus rendering Cyclocephala paraphyletic. Mimeoma is synonymized within Cyclocephala resulting in the following new combinations: Cyclocephala acuta A rrow n.comb ., Cyclocephala englemani ( R atcliffe) n.comb ., Cyclocephala maculata B urmeister n.comb ., Cyclocephala nigra ( E ndrödi) n.comb . and Cyclocephala signatoides H öhne n.comb . Our results demonstrate that pinned, museum specimens can be used to obtain DNA sequence data (particularly high‐copy gene regions) for evolutionary studies, and provide the first empirical support that host‐plant associations within cyclocephaline scarab clades are conserved at the plant family‐level.

Premise: There is a general lack of consensus on the best practices for filtering of single‐nucleotide polymorphisms (SNPs) and whether it is better to use SNPs or include flanking regions (full “locus”) in phylogenomic analyses and subsequent comparative methods.Methods: Using genotyping‐by‐sequencing data from 22 Glycine species, we assessed the effects of SNP vs. locus usage and SNP retention stringency. We compared branch length, node support, and divergence time estimation across 16 datasets with varying amounts of missing data and total size.Results: Our results revealed five aspects of phylogenomic data usage that may be generally applicable: (1) tree topology is largely congruent across analyses; (2) filtering strictly for SNP retention (e.g., 90–100%) reduces support and can alter some inferred relationships; (3) absolute branch lengths vary by two orders of magnitude between SNP and locus datasets; (4) data type and branch length variation have little effect on divergence time estimation; and (5) phylograms alter the estimation of ancestral states and rates of morphological evolution.Discussion: Using SNP or locus datasets does not alter phylogenetic inference significantly, unless researchers want or need to use absolute branch lengths. We recommend against using excessive filtering thresholds for SNP retention to reduce the risk of producing inconsistent topologies and generating low support.

PREMISE OF THE STUDY: Although asexual taxa are generally seen as evolutionary dead ends, asexuality appears to provide a short‐term benefit in some taxa, including a wider geographic distribution compared to sexual relatives. However, this may be an illusion created by multiple, morphologically cryptic, asexual lineages, each occupying a relatively small area. In this study we investigate the role of multiple lineages in the biogeography of Myriopteris gracilis Fée (Pteridaceae), a North American apomictic triploid fern species with a particularly large range.METHODS: Range‐wide asexuality was assessed by counting spores/sporangium in 606 Myriopteris gracilis specimens from across the species range, and lineage structure was assessed with both plastid DNA sequence and Genotyping By Sequencing (GBS) SNP datasets.KEY RESULTS: Spore counting of >600 specimens identified no sexual populations, establishing that Myriopteris gracilis is exclusively asexual. The plastid data estimated the crown age of M. gracilis at ca. 2.5 mya and identified two lineages, each largely confined to the eastern or western portions of the range. These groups were further subdivided by the GBS data, revealing at least seven asexual lineages of varying geographic distributions, each occupying a relatively small portion of the total range of M. gracilis.CONCLUSIONS: Although maintained exclusively through asexual reproduction, the broad distribution of Myriopteris gracilis is a compilation of numerous, independently formed asexual lineages. Since no single asexual lineage occupies the full extent of the species distribution, recurrent lineage formation should be considered when evaluating the short‐term benefit of asexuality in this taxon and others.

Mycorrhizal symbiosis has been fundamental to colonization of terrestrial ecosystems by plants, influencing population dynamics, biogeography, and their evolution^1–3. The emergence of the ancient arbuscular mycorrhizal symbiosis (AMS) was followed by the diversification of alternative mycorrhizal types, including the ericoid mycorrhizae (ErM)³. The evolution of ErM coincides with the emergence of the Ericaceae family of angiosperms and the diversification of leafy liverworts within the order Jungermanniales, as well as their expansion into boreal and high-altitude ecosystem^4–6. Despite their evolutionary and ecological relevance, little is known about the molecular and genomic basis of ErM. Here, we sequenced the nuclear genomes of two leafy liverworts from Jungermanniales, and reconstituted ErM under laboratory conditions. We demonstrated the existence of a nutrient-regulated symbiotic state that enables ErM and underlies intracellular colonization of plant tissues. Genome and functional analyses revealed that leafy liverworts retain a conserved suite of functional genes that are required for endosymbiosis in land plants. Comparative transcriptomic analysis under ErM-permissive and restrictive conditions identified gene modules associated with endosymbiosis. Transcriptome sequencing cross-comparisons of ErM and AMS identified a conserved gene module required for the intracellular accommodation of fungal symbionts, marking it as a shared feature across diverse types of land plant symbioses. Our study presents the first genomic resources for leafy liverworts, and provides the first experimental evidence that ErM evolved from AMS. This evolutionary transition involved the co-option of a nutrient-based mechanism for the establishment of ErM, and additionally the co-option of two gene modules essential for signaling and symbiont accommodation during endosymbiosis. Our data offer valuable insights and resources for understanding the molecular basis of ErM and its diversification from AMS in land plants.

To conserve water in arid environments, numerous plant lineages have independently evolved Crassulacean Acid Metabolism (CAM). Interestingly, Isoetes , an aquatic lycophyte, can also perform CAM as an adaptation to low CO ₂ availability underwater. However, little is known about the evolution of CAM in aquatic plants and the lack of genomic data has hindered comparison between aquatic and terrestrial CAM. Here, we investigated the underwater CAM in Isoetes taiwanensis by generating a high-quality genome assembly and RNA-seq time course. Despite broad similarities between CAM in Isoetes and terrestrial angiosperms, we identified several key differences. Notably, for carboxylation of PEP, Isoetes recruited the lesser-known “bacterial-type” PEPC, along with the “plant-type” exclusively used in other terrestrial CAM and C4 plants. Furthermore, we found that circadian control of key CAM pathway genes has diverged considerably in Isoetes relative to flowering plants. This suggests the existence of more evolutionary paths to CAM than previously recognized.