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opencc-zeroDec 2015View details →

Data from: Genetic structure reveals a history of multiple independent origins followed by admixture in the allopolyploid weed Salsola ryanii

It has recently become clear that many invasive species have evolved in situ via hybridization or polyploidy from progenitors which themselves are introduced species. For species formed by hybridization or polyploidy, genetic diversity within the newly formed species is influenced by the number of independent evolutionary origins of the species. For recently formed species, an analysis of genetic structure can provide insight into the number of independent origin events involved in the formation of the species. For a putative invasive allopolyploid species, the number of origins involved in the species formation, the genetic diversity present within these origins, and the level of gene flow between independent origins determines the genetic composition of the neospecies. Here we analyze the genetic structure of the newly formed allopolyploid species, Salsola ryanii, a tumbleweed which evolved within the last 20–100 years in California. We utilize the genetic structure analysis to determine that this new species is the result of at least three independent allopolyplodization events followed by gene flow between the descendants of independent origins.

opencc-zeroDec 2010View details →

Data from: Genetic diversity and multiple origins of polyploid Atriplex nummularia Lindl. (Chenopodiaceae).

Few studies have described the genetic diversity within and between populations of polyploid plant species despite the general acceptance of the importance of polyploidy in plant diversification and speciation. The genus Atriplex has a complex evolutionary history in Australia that has included polyploidy and hybridization among perennial forms. The octoploid, dioecious species Atriplex nummularia is proposed to have evolved from an octoploid ancestor in the coastal semi-arid fringe of south-western Australia, and to have spread east and diversified into taxa which occupy edaphically different habitats. Despite interest in the diversification of the genus, and the ecological and economic importance of A. nummularia, there are no descriptions of the genetic structure of the species. Nuclear microsatellite markers and principal coordinate analysis, analysis of molecular variance, Bayesian and phenetic analyses were used to investigate the diversity and taxonomic relationships of two common subspecies of A. nummularia. Genetic diversity was high overall (A = 509, A′ = 42.4, Ho = 0.824, H′ = 2.8), but values were significantly lower in the western subspecies, A. nummularia ssp. spathulata. As in other outbreeding, perennial species, most of the genetic diversity was within populations (FST = 0.125). Clear divergence of subspecies was evident in principal coordinate analysis, neighbor-joining and Bayesian clustering analyses and the differentiation of populations was very low within subspecies (FSC = 0.048). These findings support the taxonomic separation of the two subspecies. Clustering patterns based on Bayesian analyses suggested that the polyploid subspecies of A. nummularia have multiple origins.

opencc-zeroDec 2017View details →

Data from: Multiple origins of sexual dichromatism and aposematism within large carpenter bees

The evolution of reversed sexual dichromatism and aposematic coloration have long been of interest to both theoreticians and empiricists. Yet despite the potential connections between these phenomena, they have seldom been jointly studied. Large carpenter bees (genus Xylocopa) are a promising group for such comparative investigations as they are a diverse clade in which both aposematism and reversed sexual dichromatism can occur either together or separately. We investigated the evolutionary history of dichromatism and aposematism and a potential correlation of these traits with diversification rates within Xylocopa, using a newly-generated phylogeny for 179 Xylocopa species based on ultraconserved elements (UCEs). A monochromatic, inconspicuous ancestor is indicated for the genus, with subsequent convergent evolution of sexual dichromatism and aposematism in multiple lineages. Aposematism is found to co-vary with reversed sexual dichromatism in many species; however, reversed dichromatism also evolved in non-aposematic species. Bayesian Analysis of Macroevolutionary Models (BAMM) did not show increased diversification in any specific clade in Xylocopa, whereas support from Hidden State Speciation and Extinction (HiSSE) models remained inconclusive regarding an association of increased diversification rates with dichromatism or aposematism. We discuss the evolution of color patterns and diversification in Xylocopa by considering potential drivers of dichromatism and aposematism.

opencc-zeroDec 2014View details →

Data from: A molecular genetic time scale demonstrates Cretaceous origins and multiple diversification rate shifts within the order Galliformes (Aves)

The phylogeny of Galliformes (landfowl) has been studied extensively; however, the associated chronologies have been criticized recently due to misplaced or misidentified fossil calibrations. As a consequence, it is unclear whether any crown-group lineages arose in the Cretaceous and survived the Cretaceous–Paleogene (K–Pg; 65.5 Ma) mass extinction. Using Bayesian phylogenetic inference on an alignment spanning 14,539 bp of mitochondrial and nuclear DNA sequence data, four fossil calibrations, and a combination of uncorrelated lognormally distributed relaxed-clock and strict-clock models, we inferred a time-calibrated molecular phylogeny for 225 of the 291 extant Galliform taxa. These analyses suggest that crown Galliformes diversified in the Cretaceous and that three-stem lineages survived the K–Pg mass extinction. Ideally, characterizing the tempo and mode of diversification involves a taxonomically complete phylogenetic hypothesis. We used simple constraint structures to incorporate 66 data-deficient taxa and inferred the first taxon-complete phylogenetic hypothesis for the Galliformes. Diversification analyses conducted on 10,000 timetrees sampled from the posterior distribution of candidate trees show that the evolutionary history of the Galliformes is best explained by a rate-shift model including 1–3 clade-specific increases in diversification rate. We further show that the tempo and mode of diversification in the Galliformes conforms to a three-pulse model, with three-stem lineages arising in the Cretaceous and inter and intrafamilial diversification occurring after the K–Pg mass extinction, in the Paleocene–Eocene (65.5–33.9 Ma) or in association with the Eocene–Oligocene transition (33.9 Ma).

opencc-zeroDec 2016View details →

Data from: Tempo and mode of performance evolution across multiple independent origins of adhesive toe pads in lizards

Understanding macroevolutionary dynamics of trait evolution is an important endeavor in evolutionary biology. Ecological opportunity can liberate a trait as it diversifies through trait space, while genetic and selective constraints can limit diversification. While many studies have examined the dynamics of morphological traits, diverse morphological traits may yield the same or similar performance and as performance is often more proximately the target of selection, examining only morphology may give an incomplete understanding of evolutionary dynamics. Here we ask whether convergent evolution of pad-bearing lizards have followed similar evolutionary dynamics, or whether independent origins are accompanied by unique constraints and selective pressures over macroevolutionary time. We hypothesized that geckos and anoles each have unique evolutionary tempos and modes. Using performance data from 59 species, we modified Brownian Motion (BM) and Ornstein-Uhlenbeck (OU) models to account for repeated origins estimated using Bayesian ancestral state reconstructions. We discovered that adhesive performance in geckos evolved in a fashion consistent with Brownian Motion with a trend, whereas anoles evolved in bounded performance space consistent with more constrained evolution (an Ornstein-Uhlenbeck model). Our results suggest that convergent phenotypes can have quite distinctive evolutionary patterns, likely as a result of idiosyncratic constraints or ecological opportunities.

Figure 14 in REVIEW Going underwater: multiple origins and functional morphology of piercing-sucking feeding and tracheal system adaptations in water scavenger beetle larvae (Coleoptera: Hydrophiloidea)

Figure 14. Summary of the main structures related with apneustic respiratory system. A–C, Berosus decolor Knisch, 1924, light microscope photograph: A, habitus, first-instar larva, dorsal view; B; terminal spiracle, third-instar larva, dorsal view; C; detail of the abdominal spiracular trachea and tracheal gill, dorsal view. D, Berosus pallipes Brullé, 1841, abdominal spiracle, third-instar larva, dorsal view. E–H, Berosus sp., third-instar larva, SEM micrograph: E, spiracular chamber, ventral view; F; first abdominal segment bearing tracheal gill, dorsal view; G, detail of tracheal gill surface; H, abdominal spiracle. I, J, Hemiosus bruchi Knisch, 1924, third-instar larva, SEM micrograph: I, last abdominal segments, dorsal view; J, abdominal spiracle. K, Hemiosus multimaculatus (Jensen-Haarup, 1910), spiracular chamber, third-instar larva, ventral view.

Figure 15 in REVIEW Going underwater: multiple origins and functional morphology of piercing-sucking feeding and tracheal system adaptations in water scavenger beetle larvae (Coleoptera: Hydrophiloidea)

Figure 15. Phylogeny of the Hydrophiloidea with mapped evolution of tracheal system (A) and mouthparts (B, C). Two alternative ancestral state reconstructions of mouthparts, considering mouthparts of the Pelthydrus-group as: B, piercingsucking; C, chewing (only tribe Laccobiini shown). D, number of species of aquatic genera of Hydrophilidae with known larvae. Colors of branches/bars/pie-charts indicate functional morphology of mouthparts (red = piercing-sucking, blue = chewing, green = filter-feeding) and development of the tracheal system (grey = open; orange = closed).

Figure 12 in REVIEW Going underwater: multiple origins and functional morphology of piercing-sucking feeding and tracheal system adaptations in water scavenger beetle larvae (Coleoptera: Hydrophiloidea)

Figure 12. Schematic drawing of the piercing-sucking feeding mechanism: 1, sucking channel; 2, epistomal-mandibular coupling system; 3, flexible area.

Figure 13 in REVIEW Going underwater: multiple origins and functional morphology of piercing-sucking feeding and tracheal system adaptations in water scavenger beetle larvae (Coleoptera: Hydrophiloidea)

Figure 13. Summary of the main structures related with metapneustic respiratory system. A, Tropisternus latus (Brullé, 1837), spiracular chamber, first-instar larva, light microscope photograph, dorsal view. B, Helochares ventricosus Bruch, 1915, spiracular chamber, first-instar larva, light microscope photograph, dorsal view. C, Tropisternus latus (Brullé, 1837), spiracular chamber, first-instar larva, light microscope photograph, dorsal view. D, Helochares ventricosus Bruch, 1915, abdominal spiracle, first-instar larva, light microscope photograph, dorsal view. E–H, Tropisternus setiger Germar, 1824, SEM micrograph: E, spiracular chamber, third-instar larva, ventral view; F, detail of the terminal spiracle with dust filter, third-instar larva, ventral view; G, abdominal spiracle, first-instar larva, dorsal view; H, detail of the closed abdominal spiracles, first-instar larva, dorsal view. I, J, Oocyclus iguazu (Oliva 1996) third-instar larva, SEM micrograph: I, spiracular chamber, dorsal view; J, biforous abdominal spiracle, dorsal view. K, Laccobius kunashiricus Shatrovskiy, 1984, spiracular chamber, third-instar larva, SEM micrograph, dorsal view.

Figure 11 in REVIEW Going underwater: multiple origins and functional morphology of piercing-sucking feeding and tracheal system adaptations in water scavenger beetle larvae (Coleoptera: Hydrophiloidea)

Figure 11. Summary of the main structures related with piercing-sucking feeding mechanism, SEM micrograph. A, B, Berosus sp., third-instar larva: A, lobular-mandibular coupling system, dorsal view; B, detail of lobular-mandibular coupling system, ventral view. C, Laccobius (Microlaccobius) sp., third-instar larva, left epistomal lobe, dorsal view.

Figure 10 in REVIEW Going underwater: multiple origins and functional morphology of piercing-sucking feeding and tracheal system adaptations in water scavenger beetle larvae (Coleoptera: Hydrophiloidea)

Figure 10. Frame sequences of videos showing feeding behavior. A, Tropisternus latus Brullé, 1837, note that the larvae raise the head out of water while feeding. B, Hydrophilus (Dibolocelus) palpalis Brullé, 1837. C, Hemiosus dejeanii (Solier, 1849). D, Oocyclus magnifica Hebauer & Wang, 1998. See also Supporting Information, Videos S1–S4.

Figure 5 in REVIEW Going underwater: multiple origins and functional morphology of piercing-sucking feeding and tracheal system adaptations in water scavenger beetle larvae (Coleoptera: Hydrophiloidea)

Figure 5. Labroclypeal region of larvae with chewing feeding system, SEM micrograph, dorsal view. A, Tropisternus acaragua Bachmann, 1969, first-instar larva. B, Hydrochara caraboides (Linnaeus, 1758), first-instar larva. C, Hydrophilus (Dibolocelus) palpalis Brullé, 1837, second-instar larva. D, Derallus paranensis Oliva, 1981, first instar larva. E, Helochares ventricosus Bruch, 1915, first-instar larva. F, Hydroglobus puncticolle Bruch, 1915, third-instar larva. G, Dactylosternum cacti (LeConte, 1855), third-instar larva. H, Cercyon quisquilius (Linnaeus, 1761), third-instar larva, white arrow indicates labroclypeal notch. Colours: light blue, frontoclypeal region; green, gFR1, group of sensilla of nasale; violet, gFR2, group of sensilla of epistomal lobe.

Figure 1 in REVIEW Going underwater: multiple origins and functional morphology of piercing-sucking feeding and tracheal system adaptations in water scavenger beetle larvae (Coleoptera: Hydrophiloidea)

Figure 1. Head capsule of larvae with chewing (A–C) and piercing-sucking (D–I) feeding system, SEM micrograph, dorsal view. A, Hydrophilus (Dibolocelus) palpalis Brullé, 1837, second-instar larva. B, Tropisternus setiger Germar, 1824, firstinstar larva. C, Derallus paranensis Oliva, 1981, first instar larva. D, Berosus sp., third-instar larva. E, Hemiosus bruchi Knisch, 1924, third-instar larva. F, Oocyclus iguazu (Oliva 1996), third-instar larva. G, Laccobius kunashiricus Shatrovskiy, 1984, third-instar larva. H, Hybogralius hartmeyeri (Régimbart, 1908), third-instar larva, light microscope photograph. I, Epimetopus mendeli Fikáček et al. 2011, first-instar larva.

Figure 6 in REVIEW Going underwater: multiple origins and functional morphology of piercing-sucking feeding and tracheal system adaptations in water scavenger beetle larvae (Coleoptera: Hydrophiloidea)

Figure 6. Labroclypeal region of Hemiosus larvae. A, B, Hemiosus bruchi Knisch, 1924, third-instar larva, SEM micrograph, dorsal view: A, labroclypeus; B, left epistomal lobe. C–E, Hemiosus multimaculatus (Jensen-Haarup, 1910), third-instar larva, dorsal view: C, left epistomal lobe, SEM micrograph; D, detail of gFR2 serrated setae, SEM micrograph; E, left epistomal lobe, light microscope photograph. Abbreviations: EpLb, epistomal lobe; NS, nasale. Colours: light blue, frontoclypeal region; green, gFR1, group of sensilla of nasale; violet, gFR2, group of sensilla of epistomal lobe.

Figure 9 in REVIEW Going underwater: multiple origins and functional morphology of piercing-sucking feeding and tracheal system adaptations in water scavenger beetle larvae (Coleoptera: Hydrophiloidea)

Figure 9. Labium of larvae with chewing (A–B) and piercing-sucking (C–D) feeding system, dorsal view. A, Enochrus sp., first-instar larva, SEM micrograph. B, Derallus sp., first-instar larva, SEM micrograph. C, Berosus sp., third-instar larva, SEM micrograph. D, Oocyclus sapphirus Short & García, 2010, first-instar larva, light microscope photograph.

Figure 3. Piercing-sucking mandibles. A–C in REVIEW Going underwater: multiple origins and functional morphology of piercing-sucking feeding and tracheal system adaptations in water scavenger beetle larvae (Coleoptera: Hydrophiloidea)

Figure 3. Piercing-sucking mandibles. A–C, Berosus patruelis Berg, 1885, first-instar larva, SEM micrograph: A, left mandible, ventral view; B, detail of mandibular teeth, ventral view; C, right mandible, dorsal view. D–F, Laccobius hammondi Gentili, 1984, third-instar larva, SEM micrograph, dorsal view: D, left mandible; E, detail of mandibular teeth; F, right mandible. G–I, Oocyclus iguazu (Oliva, 1996) third-instar larva, SEM micrograph, dorsal view; G, left mandible; H, detail of mandibular teeth; I, right mandible.

Figure 4. Piercing-sucking mandibles. A–C in REVIEW Going underwater: multiple origins and functional morphology of piercing-sucking feeding and tracheal system adaptations in water scavenger beetle larvae (Coleoptera: Hydrophiloidea)

Figure 4. Piercing-sucking mandibles. A–C, Hybogralius hartmeyeri (Régimbart, 1908), third-instar larva, light microscope photographs, dorsal view: A, left mandible; B, detail of mandibular teeth; C, right mandible. D–F, Epimetopus mendeli Fikáček et al. 2011, first-instar larva, SEM micrograph, dorsal view: D, left mandible; E, detail of mandibular teeth; F, right mandible. Abbreviations: rc1, first retinaculum; rc2, second retinaculum; rc3, third retinaculum; pt, prostheca.