Analysis of DNA sequences of six chloroplast and nuclear genes suggests incongruence, introgression, and incomplete lineage sorting in the evolution of Lespedeza (Fabaceae)

2012 ◽  
Vol 62 (1) ◽  
pp. 346-358 ◽  
Author(s):  
Bo Xu ◽  
Ning Wu ◽  
Xin-Fen Gao ◽  
Li-Bing Zhang
Keyword(s):  
Dna Sequences ◽  
Incomplete Lineage Sorting ◽  
Nuclear Genes ◽  
Lineage Sorting

Phylogenetic relationships based on nuclear and plastid DNA sequences reveal recent diversification and discordant patterns of morphological evolution of the Chilean genera of Gilliesieae (Amaryllidaceae: Allioideae)

2020 ◽  
Vol 194 (1) ◽  
pp. 84-99
Author(s):  
Inelia Escobar ◽  
Eduardo Ruiz-Ponce ◽  
Paula J Rudall ◽  
Michael F Fay ◽  
Oscar Toro-Núñez ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Phylogenetic Relationships ◽  
Incomplete Lineage Sorting ◽  
Morphological Evolution ◽  
Strong Support ◽  
Plastid Dna ◽  
Lineage Sorting ◽  
Generic Level ◽  
Molecular Analyses ◽  
Floral Diversity

Abstract Gilliesieae are a South American tribe of Amaryllidaceae characterized by high floral diversity. Given different taxonomic interpretations and proposals for generic and specific relationships, a representative phylogenetic analysis is required to clarify the systematics of this group. The present study provides a framework for understanding phylogenetic relationships and contributing to the development of an appropriate taxonomic treatment of Gilliesieae. Molecular analyses, based on nuclear (ITS) and plastid DNA sequences (trnL-F and rbcL), resolve with strong support the monophyly of the tribe and the differentiation of two major clades. Clade I comprises the genera Gilliesia, Gethyum and Solaria and Clade II includes Miersia and Speea. These well-supported clades are mostly congruent with vegetative and karyotype characters rather than, e.g., floral symmetry. At the generic level, all molecular analyses reveal the paraphyly of Gilliesia and Miersia. Gethyum was found to be paraphyletic, resulting in the confirmation of Ancrumia as a distinct genus. Several instances of incongruent phylogenetic signals were found among data sets. The calibrated tree suggests a recent diversification of the tribe (Pliocene–Pleistocene), a contemporary process of speciation in which instances of hybridization and incomplete lineage sorting could explain patterns of paraphyly and incongruence of floral morphology.

scholarly journals An ABBA-BABA Test for Introgression Using Retroposon Insertion Data

2019 ◽  
Author(s):  
Mark S. Springer ◽  
John Gatesy
Keyword(s):  
Dna Sequences ◽  
Incomplete Lineage Sorting ◽  
Species Tree ◽  
Data Sets ◽  
Lineage Sorting ◽  
Sequence Alignments ◽  
Data Set ◽  
Short Branch ◽  
Phylogenetic Methods ◽  
Branch Lengths

AbstractDNA sequence alignments provide the majority of data for inferring phylogenetic relationships with both concatenation and coalescence methods. However, DNA sequences are susceptible to extensive homoplasy, especially for deep divergences in the Tree of Life. Retroposon insertions have emerged as a powerful alternative to sequences for deciphering evolutionary relationships because these data are nearly homoplasy-free. In addition, retroposon insertions satisfy the ‘no intralocus recombination’ assumption of summary coalescence methods because they are singular events and better approximate neutrality relative to DNA sequences commonly applied in phylogenomic work. Retroposons have traditionally been analyzed with phylogenetic methods that ignore incomplete lineage sorting (ILS). Here, we analyze three retroposon data sets for mammals (Placentalia, Laurasiatheria, Balaenopteroidea) with two different ILS-aware methods. The first approach constructs a species tree from retroposon bipartitions with ASTRAL, and the second is a modification of SVD-Quartets. We also develop a χ2 Quartet-Asymmetry Test to detect hybridization using retroposon data. Both coalescence methods recovered the same topology for each of the three data sets. The ASTRAL species tree for Laurasiatheria has consecutive short branch lengths that are consistent with an anomaly zone situation. For the Balaenopteroidea data set, which includes rorquals (Balaenopteridae) and gray whale (Eschrichtiidae), both coalescence methods recovered a topology that supports the paraphyly of Balaenopteridae. Application of the χ2 Quartet-Asymmetry Test to this data set detected 16 different quartets of species for which historical hybridization may be inferred, but significant asymmetry was not detected in the placental root and Laurasiatheria analyses.

scholarly journals Reticulate Evolution, Ancient Chloroplast Haplotypes, and Rapid Radiation of the Australian Plant Genus Adenanthos (Proteaceae)

2021 ◽  
Vol 8 ◽  
Author(s):  
Francis J. Nge ◽  
Ed Biffin ◽  
Kevin R. Thiele ◽  
Michelle Waycott
Keyword(s):  
Dna Sequences ◽  
Large Scale ◽  
Incomplete Lineage Sorting ◽  
Plastid Dna ◽  
Lineage Sorting ◽  
Endemic Plant ◽  
Rapid Radiation ◽  
High Genetic Diversity ◽  
Chloroplast Haplotypes ◽  
Analytical Approaches

Cytonuclear discordance, commonly detected in phylogenetic studies, is often attributed to hybridization and/or incomplete lineage sorting (ILS). New sequencing technologies and analytical approaches can provide new insights into the relative importance of these processes. Hybridization has previously been reported in the Australian endemic plant genus Adenanthos (Proteaceae). Like many Australian genera, Adenanthos is of relatively ancient origin, and provides an opportunity to examine long-term evolutionary consequences of gene flow between lineages. Using a hybrid capture approach, we assembled densely sampled low-copy nuclear and plastid DNA sequences for Adenanthos, inferred its evolutionary history, and used a Bayesian posterior predictive approach and coalescent simulations to assess relative contributions of hybridization and ILS to cytonuclear discordance. Our analyses indicate that strong incongruence detected between our plastid and nuclear phylogenies is not only the result of ILS, but also results from extensive ancient introgression as well as recent chloroplast capture and introgression between extant Adenanthos species. The deep reticulation was also detected from long-persisting chloroplast haplotypes shared between evolutionarily distant species. These haplotypes may have persisted for over 12 Ma in localized populations across southwest Western Australia, indicating that the region is not only an important area for old endemic lineages and accumulation of species, but is also characterized by persistence of high genetic diversity. Deep introgression in Adenanthos coincided with the rapid radiation of the genus during the Miocene, a time when many Australian temperate plant groups radiated in response to large-scale climatic change. This study suggests that ancient introgression may play an important role in the evolution of the Australian flora more broadly.

Hippocampus queenslandicus Horne, 2001 - a new seahorse species or yet another synonym?

2007 ◽  
Vol 55 (3) ◽  
pp. 139 ◽  
Author(s):  
Peter R. Teske ◽  
Sara A. Lourie ◽  
Conrad A. Matthee ◽  
David M. Green
Keyword(s):  
Dna Sequences ◽  
Incomplete Lineage Sorting ◽  
Strong Support ◽  
Mitochondrial Control Region ◽  
Morphological Characters ◽  
Morphological Data ◽  
Lineage Sorting ◽  
Species Status ◽  
The Past ◽  
Species Descriptions

During the past six years, 15 new seahorse species (Syngnathidae: Hippocampus) have been described on the basis of morphological characters. This approach is known to be problematic, and most species names in Hippocampus are now considered to be synonyms. Genetic methods have great potential to resolve the confused taxonomy of the genus, but none have yet been incorporated into species descriptions. In the present study, mitochondrial control region and cytochrome b DNA sequences, as well as morphological data from the recently described Queensland seahorse, Hippocampus queenslandicus Horne, 2001, were compared with corresponding data from closely related seahorse species to determine whether there is strong support for distinction of this taxon. The haplotypes of H. queenslandicus were nested among haplotypes belonging to two of the three major Southeast Asian lineages of H. spinosissimus Weber, 1913. Although incomplete lineage sorting characteristic of very recently diverged species cannot be ruled out, the genetic results suggest that H. queenslandicus is paraphyletic. Morphometric analysis further fails to provide strong support for the species status of H. queenslandicus. We conclude that support for the distinctness of H. queenslandicus is weak, and indicate that it is a synonym of H. spinosissimus. The taxonomic validity of other recently described seahorse species should be similarly scrutinised using combined genetic and detailed morphological methods.

scholarly journals Multiple nuclear genes and retroposons support vicariance and dispersal of the palaeognaths, and an Early Cretaceous origin of modern birds

2012 ◽  
Vol 279 (1747) ◽  
pp. 4617-4625 ◽  
Author(s):  
Oliver Haddrath ◽  
Allan J. Baker
Keyword(s):  
Incomplete Lineage Sorting ◽  
Gene Tree ◽  
Species Tree ◽  
Nuclear Genes ◽  
Lineage Sorting ◽  
Posterior Density ◽  
Crown Group ◽  
Gene Sets ◽  
Gene Tree Discordance ◽  
Highest Posterior Density

The origin and timing of the diversification of modern birds remains controversial, primarily because phylogenetic relationships are incompletely resolved and uncertainty persists in molecular estimates of lineage ages. Here, we present a species tree for the major palaeognath lineages using 27 nuclear genes and 27 archaic retroposon insertions. We show that rheas are sister to the kiwis, emu and cassowaries, and confirm ratite paraphyly because tinamous are sister to moas. Divergence dating using 10 genes with broader taxon sampling, including emu, cassowary, ostrich, five kiwis, two rheas, three tinamous, three extinct moas and 15 neognath lineages, suggests that three vicariant events and possibly two dispersals are required to explain their historical biogeography. The age of crown group birds was estimated at 131 Ma (95% highest posterior density 122–138 Ma), similar to previous molecular estimates. Problems associated with gene tree discordance and incomplete lineage sorting in birds will require much larger gene sets to increase species tree accuracy and improve error in divergence times. The relatively rapid branching within neoaves pre-dates the extinction of dinosaurs, suggesting that the genesis of the radiation within this diverse clade of birds was not in response to the Cretaceous–Paleogene extinction event.

Phylogeny and evolution of the green lizards, Lacerta spp. (Squamata: Lacertidae) based on mitochondrial and nuclear DNA sequences

2005 ◽  
Vol 26 (3) ◽  
pp. 271-285 ◽  
Author(s):  
D. James Harris ◽  
Nuno Ferrand ◽  
Eduardo Crespo ◽  
Raquel Godinho
Keyword(s):  
Dna Sequences ◽  
Phylogenetic Relationships ◽  
Nuclear Dna ◽  
Incomplete Lineage Sorting ◽  
Bird Species ◽  
Rrna Genes ◽  
12S Rrna ◽  
Lineage Sorting ◽  
Extant Species ◽  
Mitochondrial Cytochrome B

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.

scholarly journals ILS-Aware Analyses of Retroelement Insertions in the Anomaly Zone

2020 ◽  
Author(s):  
Erin K. Molloy ◽  
John Gatesy ◽  
Mark S. Springer
Keyword(s):  
Dna Sequences ◽  
Incomplete Lineage Sorting ◽  
Species Tree ◽  
Species Trees ◽  
Lineage Sorting ◽  
Short Branch ◽  
Multispecies Coalescent ◽  
Branch Lengths ◽  
Tree Estimation ◽  
Infinite Sites Model

AbstractA major shortcoming of concatenation methods for species tree estimation is their failure to account for incomplete lineage sorting (ILS). Coalescence methods explicitly address this problem, but make various assumptions that, if violated, can result in worse performance than concatenation. Given the challenges of analyzing DNA sequences with both concatenation and coalescence methods, retroelement insertions have emerged as powerful phylogenomic markers for species tree estimation. We show that two recently proposed methods, SDPquartets and ASTRAL_BP, are statistically consistent estimators of the species tree under the multispecies coalescent model, with retroelement insertions following a neutral infinite sites model of mutation. The accuracy of these and other methods for inferring species trees with retroelements has not been assessed in simulation studies. We simulate retroelements for four different species trees, including three with short branch lengths in the anomaly zone, and assess the performance of eight different methods for recovering the correct species tree. We also examine whether ASTRAL_BP recovers accurate internal branch lengths for internodes of various lengths (in coalescent units). Our results indicate that two recently proposed ILS-aware methods, ASTRAL_BP and SDPquartets, as well as the newly proposed ASTRID_BP, always recover the correct species tree on data sets with large numbers of retroelements even when there are extremely short species-tree branches in the anomaly zone. Dollo parsimony performed almost as well as these ILS-aware methods. By contrast, unordered parsimony, polymorphism parsimony, and MDC recovered the correct species tree in the case of a pectinate tree with four ingroup taxa in the anomaly zone, but failed to recover the correct tree in more complex anomaly-zone situations with additional lineages impacted by extensive incomplete lineage sorting. Camin-Sokal parsimony always reconstructed an incorrect tree in the anomaly zone. ASTRAL_BP accurately estimated branch lengths when internal branches were very short as in anomaly zone situations, but branch lengths were upwardly biased by more than 35% when species tree branches were longer. We derive a mathematical correction for these distortions, assuming the expected number of new retroelement insertions per generation is constant across the species tree. We also show that short branches do not need to be corrected even when this assumption does not hold; therefore, the branch lengths estimates produced by ASTRAL_BP may provide insight into whether an estimated species tree is in the anomaly zone.

Nuclear and plastid DNA sequences reveal complex reticulate patterns in Australian water-lilies (Nymphaea subgenus Anecphya, Nymphaeaceae)

2008 ◽  
Vol 21 (4) ◽  
pp. 229 ◽  
Author(s):  
Cornelia Löhne ◽  
Thomas Borsch ◽  
Surrey W. L. Jacobs ◽  
C. Barre Hellquist ◽  
John H. Wiersema
Keyword(s):  
Dna Sequences ◽  
Incomplete Lineage Sorting ◽  
Phylogenetic Signal ◽  
Plastid Dna ◽  
Molecular Data ◽  
Lineage Sorting ◽  
Australian Water ◽  
Length Polymorphisms ◽  
Close Relationship ◽  
Nuclear Its

This study represents the first comprehensive analysis of phylogenetic relationships within the Australian water-lilies, Nymphaea subg. Anecphya. Our 51-accession dataset covers all 10 species of the subgenus, except the newly described N. alexii, and includes information from the nuclear ITS as well as from the chloroplast trnT–trnF region. The results show that molecular data are consistent with morphology, because the subdivision of subg. Anecphya into two major clades, a large-seeded and a small-seeded group, could be confirmed. Within the large-seeded group, Nymphaea atrans and N. immutabilis seem to form one clade, whereas samples of N. gigantea, N. georginae, N. macrosperma and N. carpentariae form another. Relationships within the small-seeded group, containing all samples of N. violacea, N. elleniae and N. hastifolia, are less clear, since the trees obtained from the chloroplast and the nuclear marker are incongruent. The samples of N. violacea do not form a monophyletic group in each of the trees, but—at least in the ITS tree—group with either N. elleniae or N. hastifolia/Ondinea, respectively. Polymorphisms among ITS paralogues, i.e. substitutions at single nucleotide positions and length polymorphisms, have been observed in some samples of N. violacea. This fact as well as the incongruent phylogenetic signal obtained from the chloroplast and the nuclear genomes point to recent hybridisation or introgression in this group. Remarkably, Ondinea purpurea is resolved within the small-seeded group by both markers and seems to have a close relationship to N. hastifolia. Although incomplete lineage sorting cannot be fully excluded to explain high variability in N. violacea, molecular data potentially hint to a case of still imperfect taxonomy.

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