Reconstructing phylogenetic relationships at the micro- and macroevoutionary levels within the same tree is problematic because of the need to use different data types and analytical frameworks. We ...test the power of target enrichment to provide phylogenetic resolution based on DNA sequences from above species to within populations, using a large herbarium sampling and Euphorbia balsamifera (Euphorbiaceae) as a case study.
Target enrichment with custom probes was combined with genome skimming (Hyb-Seq) to sequence 431 low-copy nuclear genes and partial plastome DNA. We used supermatrix, multi-species-coalescent approaches, and Bayesian dating to estimate phylogenetic relationships and divergence times.
Euphorbia balsamifera, with a disjunct Rand Flora-type distribution at opposite sides of Africa, comprises three well-supported subspecies: western Sahelian sepium is sister to eastern African-southern Arabian adenensis and Macaronesian-southwest Moroccan balsamifera. Lineage divergence times support Late Miocene to Pleistocene diversification and climate-driven vicariance to explain the Rand Flora pattern.
We show that probes designed using genomic resources from taxa not directly related to the focal group are effective in providing phylogenetic resolution at deep and shallow evolutionary levels. Low capture efficiency in herbarium samples increased the proportion of missing data but did not bias estimation of phylogenetic relationships or branch lengths.
•We trace 97 million years of bromeliad adaptation, biogeography, and species diversification.•We use these data to test an integrative model for bromeliad evolution.•Patterns of correlated and ...contingent evolution are consistent with this model.•Diversification rates are significantly higher in epiphytic, tank-forming, bird-pollinated, and montane lineages.•86% Of bromeliad species richness reflects six major adaptive radiations in different areas.
We present an integrative model predicting associations among epiphytism, the tank habit, entangling seeds, C3 vs. CAM photosynthesis, avian pollinators, life in fertile, moist montane habitats, and net rates of species diversification in the monocot family Bromeliaceae. We test these predictions by relating evolutionary shifts in form, physiology, and ecology to time and ancestral distributions, quantifying patterns of correlated and contingent evolution among pairs of traits and analyzing the apparent impact of individual traits on rates of net species diversification and geographic expansion beyond the ancestral Guayana Shield. All predicted patterns of correlated evolution were significant, and the temporal and spatial associations of phenotypic shifts with orogenies generally accorded with predictions. Net rates of species diversification were most closely coupled to life in fertile, moist, geographically extensive cordilleras, with additional significant ties to epiphytism, avian pollination, and the tank habit. The highest rates of net diversification were seen in the bromelioid tank-epiphytic clade (Dcrown=1.05My−1), associated primarily with the Serra do Mar and nearby ranges of coastal Brazil, and in the core tillandsioids (Dcrown=0.67My−1), associated primarily with the Andes and Central America. Six large-scale adaptive radiations and accompanying pulses of speciation account for 86% of total species richness in the family. This study is among the first to test a priori hypotheses about the relationships among phylogeny, phenotypic evolution, geographic spread, and net species diversification, and to argue for causality to flow from functional diversity to spatial expansion to species diversity.
The origins and evolution of the outstanding Neotropical biodiversity are a matter of intense debate. A comprehensive understanding is hindered by the lack of deep-time comparative data across wide ...phylogenetic and ecological contexts. Here, we quantify the prevailing diversification trajectories and drivers of Neotropical diversification in a sample of 150 phylogenies (12,512 species) of seed plants and tetrapods, and assess their variation across Neotropical regions and taxa. Analyses indicate that Neotropical diversity has mostly expanded through time (70% of the clades), while scenarios of saturated and declining diversity account for 21% and 9% of Neotropical diversity, respectively. Five biogeographic areas are identified as distinctive units of long-term Neotropical evolution, including Pan-Amazonia, the Dry Diagonal, and Bahama-Antilles. Diversification dynamics do not differ across these areas, suggesting no geographic structure in long-term Neotropical diversification. In contrast, diversification dynamics differ across taxa: plant diversity mostly expanded through time (88%), while a substantial fraction (43%) of tetrapod diversity accumulated at a slower pace or declined towards the present. These opposite evolutionary patterns may reflect different capacities for plants and tetrapods to cope with past climate changes.
Premise: Bromeliaceae form a large, ecologically diverse family of angiosperms native to the New World. We use a bromeliad phylogeny based on eight plastid regions to analyze relationships within the ...family, test a new, eight-subfamily classification, infer the chronology of bromeliad evolution and invasion of different regions, and provide the basis for future analyses of trait evolution and rates of diversification. Methods: We employed maximum-parsimony, maximum-likelihood, and Bayesian approaches to analyze 9341 aligned bases for four outgroups and 90 bromeliad species representing 46 of 58 described genera. We calibrate the resulting phylogeny against time using penalized likelihood applied to a monocot-wide tree based on plastid ndhF sequences and use it to analyze patterns of geographic spread using parsimony, Bayesian inference, and the program S-DIVA. Results: Bromeliad subfamilies are related to each other as follows: (Brocchinioideae, (Lindmanioideae, (Tillandsioideae, (Hechtioideae, (Navioideae, (Pitcairnioideae, (Puyoideae, Bromelioideae))). Bromeliads arose in the Guayana Shield ca. 100 million years ago (Ma), spread centrifugally in the New World beginning ca. 16–13 Ma, and dispersed to West Africa ca. 9.3 Ma. Modern lineages began to diverge from each other roughtly 19 Ma. Conclusions: Nearly two-thirds of extant bromeliads belong to two large radiations: the core tillandsioids, originating in the Andes ca. 14.2 Ma, and the Brazilian Shield bromelioids, originating in the Serro do Mar and adjacent regions ca. 9.1 Ma.
Croton scarciesii (Euphorbiaceae-Crotonoideae), a rheophytic shrub from West Africa, is shown to have been misplaced in Croton for 120 years, having none of the diagnostic characters of that genus, ...but rather a set of characters present in no known genus of the family. Pollen analysis shows that the new genus Karima belongs to the inaperturate crotonoid group. Analysis of a concatenated molecular dataset combining trnL-F and rbcL sequences positioned Karima as sister to Neoholstia from south eastern tropical Africa in a well-supported clade comprised of genera of subtribes Grosserineae and Neoboutonieae of the inaperturate crotonoid genera. Several morphological characters support the relationship of Karima with Neoholstia, yet separation is merited by numerous characters usually associated with generic rank in Euphorbiaceae. Quantitative ecological data and a conservation assessment supplement illustrations and descriptions of the taxon.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The leafy spurges, Euphorbia subg. Esula, make up one of four main lineages in Euphorbia. The subgenus comprises about 480 species, most of which are annual or perennial herbs, but with a small ...number of dendroid shrubs and nearly leafless, pencil–stemmed succulents as well. The subgenus constitutes the primary northern temperate radiation in Euphorbia. While the subgenus is most diverse from central Asia to the Mediterranean region, members of the group also occur in Africa, in the Indo–Pacific region, and in the New World. We have assembled the largest worldwide sampling of the group to date (273 spp.), representing most of the taxonomic and geographic breadth of the subgenus. We performed phylogenetic analyses of sequence data from the nuclear ribosomal ITS and plastid ndhF regions. Our individual and combined analyses produced well–resolved phylogenies that confirm many of the previously recognized clades and also establish a number of novel groupings and placements of previously enigmatic species. Euphorbia subg. Esula has a clear Eurasian center of diversity, and we provide evidence for four independent arrivals to the New World and three separate colonizations of tropical and southern Africa. One of the latter groups further extends to Madagascar and New Zealand, and to more isolated islands such as Réunion and Samoa. Our results confirm that the dendroid shrub and stem–succulent growth forms are derived conditions in E. subg. Esula. Stem–succulents arose twice in the subgenus and dendroid shrubs three times. Based on the molecular phylogeny, we propose a new classification for E. subg. Esula that recognizes 21 sections (four of them newly described and two elevated from subsectional rank), and we place over 95% of the accepted species in the subgenus into this new classification.
Croton guaritensis
, sp. nov. is here described, illustrated, and classified based on morphological and molecular data. The new species is restricted to the Pampa biome where it grows around rocky ...outcrops. Examination of the morphology from herbarium collections and field observations, as well as evidence from molecular analysis, indicate that
Croton guaritensis
belongs to
Croton
section
Barhamia
subsection
Medea
.
Croton
subsection
Medea
is represented by several rare and endemic species and stands out by its glandular structures in stipules, bracts, and sepals. The new species differs from other species of this subsection in the indumentum on branches and leaves, which consists of subentire lepidote trichomes, and in the sepals of staminate and pistillate flowers that have stipitate glands. An identification key to the new species and closely related taxa in southern Brazil is provided, as well as a preliminary conservation status.
The formerly monotypic genus Paranecepsia Radcl.-Sm. is expanded with the description and illustration of a second species, Paranecepsia andrafiabensis Barberá & O.Lachenaud sp. nov. Molecular ...phylogenetic analyses of plastid rbcL and trnL-F data confirm a sister relationship between the new species and P. alchorneifolia Radcl.-Sm., as members of the alchorneoids clade. Paranecepsia andrafiabensis sp. nov. is notable for expanding the character states for the genus (now including both 2- and 3-locular ovary species) and broadening the geographic range of the genus from continental Africa to Madagascar. The new species adds to the diverse karst limestone endemics of northwestern Madagascar, where it has a very restricted distribution at the base of the western wall of the Ankarana tsingy. An amended generic description of Paranecepsia and a key to the species are also presented. Paranecepsia andrafiabensis sp. nov. is provisionally assessed as VU D1 based on the IUCN Red List criteria.
We describe Croton calcareus Riina & Mateo-Ram. sp. nov., a new species in Croton section Cyclostigma (dragon’s blood trees) from the state of Chiapas (Mexico). This species is a small tree growing ...in dry forest on calcareous substrates. Both morphological and molecular data support C. calcareus sp. nov. as a new species closely related to C. redolens, another dry forest taxon from northern Venezuela. We provide illustrations, a distribution map and suggestions for species conservation status. The new species along with Croton draco are the only known representatives of C. section Cyclostigma occurring in Mexico.
We describe and illustrate Croton restingae Sodré & Riina sp. nov., a new species endemic to a restricted area in the state of Rio de Janeiro, Brazil, characterized by a particular type of vegetation ...of the Atlantic Forest known as restinga. The new species belongs to Croton sect. Adenophylli subsect. Laceratoglandulosus, which is supported by morphology and a phylogenetic analysis based on nrDNA ITS sequence data. Croton restingae is most closely related to C. echioides and C. laceratoglandulosus, also in subsect. Laceratoglandulosus, with which it shares the fruit columella with three non-inflated, flat or slightly ascending apical appendages. Croton restingae differs from them by its sessile or shortly stipitate leaf nectaries, revolute pistillate sepals, styles distally 2-fid and basally united forming a column, and larger capsules (7.5–8 × 8.5–9.3 mm). Croton restingaeʼs habitat, conservation status, phenology, morphology and phylogenetic relationships are discussed, and a map with its geographic distribution is also included.
PDF
