A chloroplast phylogeny of Zieria (Rutaceae) in Australia and New Caledonia shows widespread incongruence with species-level taxonomy

2014 ◽  
Vol 27 (6) ◽  
pp. 427 ◽  
Author(s):  
Rosemary A. Barrett ◽  
Michael J. Bayly ◽  
Marco F. Duretto ◽  
Paul I. Forster ◽  
Pauline Y. Ladiges ◽  
...  

This study presents a molecular phylogeny of Zieria Sm., a genus of shrubs and small trees, with 59 species in Australia and one endemic to New Caledonia. The phylogeny is based on four cpDNA markers and 116 samples representing all species of Zieria except one, and the monotypic outgroup Neobyrnesia suberosa. The New Caledonian species, Z. chevalieri, was resolved as sister to a well supported clade of all Australian taxa. There was widespread incongruence between the cpDNA tree and species-level taxonomy, with 14 species shown as polyphyletic or paraphyletic. These included widespread species (e.g. Z. smithii and Z. arborescens, each falling in at least four well supported clades) and some with narrow geographic ranges (e.g. Z. alata and Z. oreocena). No species represented by three or more samples was resolved as monophyletic. We suggest that a combination of factors explains this incongruence, including regional cpDNA introgression (chloroplast capture), incomplete lineage sorting and inappropriate taxonomic boundaries. The cpDNA phylogeny provides useful insight into the evolution of Zieria but, because of its complexity, does not provide a clear basis for assessing phylogenetic relationships and monophyly of taxa. Better understanding of relationships, taxon limits and evolutionary processes in Zieria will require comparisons with nuclear DNA markers and critical assessment of morphological and genetic variation in widespread species.

2018 ◽  
Vol 31 (1) ◽  
pp. 16 ◽  
Author(s):  
Rosemary A. Barrett ◽  
Michael J. Bayly ◽  
Marco F. Duretto ◽  
Paul I. Forster ◽  
Pauline Y. Ladiges ◽  
...  

This study presents a phylogeny of Zieria Sm. (Rutaceae) based on sequences of internal transcribed spacer and external transcribed spacer regions of nrDNA, and using Neobyrnesia suberosa J.A.Armstr. as the outgroup. The phylogeny includes 109 samples, representing 58 of the 60 currently recognised species of Zieria, with multiple accessions of most. Ten species were resolved as monophyletic on the basis of two, or in one case four, samples. Monophyly of four species was neither supported nor rejected, and all other species with more than one accession were resolved as polyphyletic or paraphyletic. Results showed that divergent paralogues of nrDNA are present in some individuals, although the underlying evolutionary process that gave rise to those paralogues is uncertain. Divergent paralogues within genomes could predate speciation and be variably retained or variably detected within the species sampled here; alternatively, they could represent novel nrDNA combinations formed through hybridisation after speciation. There was no strong evidence for recombination between paralogues or that paralogues represent pseudogenes. Variation of nrDNA sequences was clearly incongruent with previously published cpDNA variation, with the nrDNA potentially providing a better indication of species relationships in Zieria. Evidence for this comes from the greater level of congruence, in some species at least, between nrDNA and existing species-level taxonomy than between cpDNA and taxonomy. Incomplete lineage sorting is proposed as a plausible cause for much of the conflict between nrDNA and cpDNA in Zieria, although, in most cases, there was insufficient information to identify the underlying causes with confidence. Implications for species-level taxonomy are discussed.


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6476 ◽  
Author(s):  
Andrinajoro R. Rakotoarivelo ◽  
Paul O’Donoghue ◽  
Michael W. Bruford ◽  
Yoshan Moodley

Background The bushbuck, Tragelaphus scriptus, is a widespread and ecologically diverse ungulate species complex within the spiral-horned antelopes. This species was recently found to consist of two genetically divergent but monophyletic lineages, which are paraphyletic at mitochondrial (mt)DNA owing to an ancient interspecific hybridization event. The Scriptus lineage (T. s. scriptus) inhabits the north-western half of the African continent while Sylvaticus (T. s. sylvaticus) is found in the south-eastern half. Here we test hypotheses of historical demography and adaptation in bushbuck using a higher-resolution framework, with four nuclear (MGF, PRKCI, SPTBN, and THY) and three new mitochondrial markers (cytochrome b, 12S rRNA, and 16S rRNA). Methods Genealogies were reconstructed for the mitochondrial and nuclear data sets, with the latter dated using fossil calibration points. We also inferred the demographic history of Scriptus and Sylvaticus using coalescent-based methods. To obtain an overview of the origins and ancestral colonisation routes of ancestral bushbuck sequences across geographic space, we conducted discrete Bayesian phylogeographic and statistical dispersal-vicariance analyses on our nuclear DNA data set. Results Both nuclear DNA and mtDNA support previous findings of two genetically divergent Sylvaticus and Scriptus lineages. The three mtDNA loci confirmed 15 of the previously defined haplogroups, including those with convergent phenotypes. However, the nuclear tree showed less phylogenetic resolution at the more derived parts of the genealogy, possibly due to incomplete lineage sorting of the slower evolving nuclear genome. The only exception to this was the montane Menelik’s bushbuck (Sylvaticus) of the Ethiopian highlands, which formed a monophyletic group at three of four nuclear DNA loci. We dated the coalescence of the two lineages to a common ancestor ∼2.54 million years ago. Both marker sets revealed similar demographic histories of constant population size over time. We show that the bushbuck likely originated in East Africa, with Scriptus dispersing to colonise suitable habitats west of the African Rift and Sylvaticus radiating from east of the Rift into southern Africa via a series of mainly vicariance events. Discussion Despite lower levels of genetic structure at nuclear loci, we confirmed the independent evolution of the Menelik’s bushbuck relative to the phenotypically similar montane bushbuck in East Africa, adding further weight to previous suggestions of convergent evolution within the bushbuck complex. Perhaps the most surprising result of our analysis was that both Scriptus and Sylvaticus populations remained relatively constant throughout the Pleistocene, which is remarkable given that this was a period of major climatic and tectonic change in Africa, and responsible for driving the evolution of much of the continent’s extant large mammalian diversity.


Phytotaxa ◽  
2019 ◽  
Vol 413 (1) ◽  
pp. 11-26 ◽  
Author(s):  
FATEMEH HOJJATI ◽  
ROBERT P. ADAMS ◽  
RANDALL G. TERRY

Previous studies of nrDNA (nuclear DNA) of Juniperus seravschanica indicated its nuclear DNA (ITS) was from an ancestor of J. polycarpos. However, analysis of cpDNA (chloroplast DNA) suggested the taxon had derived its chloroplast from an ancestor of J. foetidissima. That study has been viewed as putative, because the ITS region is sometimes unreliable for the detection of ancestral hybrids due to concerted evolution and lineage sorting. The recent availability of several single copy nuclear genes (SCNGs) with primers specifically designed for Juniperus presented an opportunity to fully investigate this case of putative chloroplast capture. Three phylogenetic analyses using five SCNGs (LHCA4, maldehy, myb, CnAIP3 and 4CL), ITS region, and four cpDNAs (petN- psbM, trnD-trnT, trnL-trnF and trnS-trnG) were performed on J. seravschanica, as well as other members of the J. excelsa complex: J. excelsa, J. polycarpos, and J. p. var. turcomanica. Analyses revealed incongruence between SCNGs, ITS region and cpDNA showing that J. seravschanica contains an ancestral J. foetidissima/ J. thruifera cp genome. In addition, the phylogenies indicate that the J. excelsa complex is composed of three distinct clades at the species level: J. excelsa, J. polycarpos and J. seravschanica and two varieties of J. polycarpos: J. p. var. polycarpos and J. p. var. turcomanica.


2004 ◽  
Vol 52 (4) ◽  
pp. 459 ◽  
Author(s):  
M. Byrne ◽  
B. Hines

Comparative phylogeography can reveal significant historical events that have had common influences on species with similar distributions. Phylogeographic analyses of eucalypts should provide insight into the influence of historical processes, since eucalypts are a dominant component of the Australian flora. However, use of chloroplast DNA in eucalypts is complicated by sharing of haplotypes among species, which has been attributed to hybridisation and introgression, although these patterns could also be accounted for by incomplete lineage sorting of ancestral polymorphism. Phylogeographic patterns in the cp genome of E. loxophleba Benth., a widespread species throughout southern Western Australia, were investigated by using RFLP analysis. The chloroplast diversity was structured into two geographically distinct lineages and nested clade analysis inferred historical fragmentation as the major influence on the phylogeographic pattern. The divergence between the lineages and their geographic distributions were similar to geographically discrete divergent lineages that have been identified in two other unrelated species from different families in southern Western Australia. Congruence of phylogeographic patterns in the three species provides evidence to support the hypothesis of significant influence of climatic instability during the Pleistocene caused by cyclic contraction and expansion of the mesic and arid zones.


ZooKeys ◽  
2020 ◽  
Vol 977 ◽  
pp. 101-161
Author(s):  
Shengchao Shi ◽  
Meihua Zhang ◽  
Feng Xie ◽  
Jianping Jiang ◽  
Wulin Liu ◽  
...  

Multiple disciplines can help to discover cryptic species and resolve taxonomic confusions. The Asian horned toad genus Megophryssensu lato as a diverse group was proposed to contain dozens of cryptic species. Based on molecular phylogenetics, morphology, osteology, and bioacoustics data, the species profiles of Megophrys toads in the eastern corner of Himalayas in Medog County, Tibet Autonomous Region, China was investigated. The results indicated that this small area harbored at least four Megophrys species, i.e., M. medogensis, M. pachyproctus, Megophrys zhouisp. nov., and Megophrys yeaesp. nov., the latter two being described in this study. Additionally, the mitochondrial DNA trees nested the low-middle-elevation and high-elevation groups of M. medogensis into a monophyletic group, being in discordance with the paraphyletic relationship between them revealed in the nuclear DNA trees. The findings highlighted the underestimated biodiversity in Himalayas, and further indicated that the Megophrys toads here have been probably experienced complicated evolutionary history, for example, introgression between clades or incomplete lineage sorting and niche divergences in microhabitats. Anyway, it is urgent for us to explore the problems because these toads are suffering from increasing threats from human activities and climatic changes.


Author(s):  
Robert D. Edwards ◽  
Michael D. Crisp ◽  
Lyn G. Cook

The Australian monsoon tropics are currently dominated by savanna and tropical woodland biomes that have arisen in response to a cooling and drying trend within the past ~3 million years. It is expected that organisms well adapted to these conditions have expanded into available habitats, leading to the differentiation of populations and species across this landscape, a process that could be magnified by the presence of several biogeographic barriers. The broad-leaved paperbark (Melaleuca leucadendra (L.) L.) complex is one such group of plants, with 14 poorly morphologically differentiated species occupying large overlapping distributions across the region, and across several recognised biogeographic barriers. Using phylogenetic and network analyses of nuclear and plastid sequences, we tested species limits among currently described species within the complex and for phylogeographic structure within species across seven of these barriers. Overall, our data suggested patterns of differentiation among species consistent with the early to middle stages of incomplete lineage sorting, and evidence for an idiosyncratic cryptic response of species to biogeographic barriers. Unexpectedly, we found a deep molecular split across all species, broadly coinciding with the northern part of the Great Dividing Range, a feature not typically considered to be a barrier to dispersal. Our study has offered one of the first insights into the dynamics within and among widespread species across the north of Australia, suggesting considerably more geographic structure than was previously recognised.


2005 ◽  
Vol 26 (3) ◽  
pp. 271-285 ◽  
Author(s):  
D. James Harris ◽  
Nuno Ferrand ◽  
Eduardo Crespo ◽  
Raquel Godinho

AbstractPartial DNA sequences from three mitochondrial (cytochrome b, 12S rRNA and 16S rRNA) and two nuclear (β-fibrinogen intron 7 and C-mos) genes were used to estimate the phylogenetic relationships among all eight extant species of green lizards, Lacerta sensu stricto, and many currently recognized subspecies. All eight species form a monophyletic group. L. agilis, L. schreiberi and L. strigata are genetically well differentiated species. L. trilineata and L. pamphylica are not monophyletic units based on analyses of the β-fibrinogen intron 7. Lacerta media is closely related to some Lacerta trilineata. L. bilineata and L. viridis are closely related, and recognition of L. bilineata as a distinct species makes L. viridis paraphyletic also. For both L. bilineata and L. viridis, some subspecies appear to remain in their southern glacial refugia, while a single genetic entity shows successfully postglacial expansion. The topology derived from C-mos variation is concordant with that derived from mtDNA, with substitutions occurring at a similar rate to that of transversions in the rRNA genes. Although C-mos is typically used at deeper taxonomic levels it is also phylogenetically informative within green lizards. β-fibrinogen intron 7, typically used for assessing phylogenetic relationships among bird species, is a useful phylogenetic marker for reptiles also, showing considerable variation between species. There is not complete concordance between estimates of relationships derived from the mtDNA and nuclear markers, probably because rapid diversification led to incomplete lineage sorting in the green lizards. Introgression could also be occuring between some species.


Taxon ◽  
2010 ◽  
Vol 59 (3) ◽  
pp. 829-840 ◽  
Author(s):  
Maia Gurushidze ◽  
Reinhard M. Fritsch ◽  
Frank R. Blattner

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jianxiang Ma ◽  
Pengchuan Sun ◽  
Dandan Wang ◽  
Zhenyue Wang ◽  
Jiao Yang ◽  
...  

AbstractMost extant angiosperms belong to Mesangiospermae, which comprises eudicots, monocots, magnoliids, Chloranthales and Ceratophyllales. However, phylogenetic relationships between these five lineages remain unclear. Here, we report the high-quality genome of a member of the Chloranthales lineage (Chloranthus sessilifolius). We detect only one whole genome duplication within this species and find that polyploidization events in different Mesangiospermae lineage are mutually independent. We also find that the members of all floral development-related gene lineages are present in C. sessilifolius despite its extremely simplified flower. The AP1 and PI genes, however, show a weak floral tissue-specialized expression. Our phylogenomic analyses suggest that Chloranthales and magnoliids are sister groups, and both are together sister to the clade comprising Ceratophyllales and eudicots, while the monocot lineage is sister to all other Mesangiospermae. Our findings suggest that in addition to hybridization, incomplete lineage sorting may largely account for phylogenetic inconsistencies between the observed gene trees.


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