Towards resolving the evolutionary history of Caucasian pears (Pyrus, Rosaceae)-Phylogenetic relationships, divergence times and leaf trait evolution

2017 ◽  
Vol 56 (1) ◽  
pp. 35-47 ◽  
Author(s):  
Nadja Korotkova ◽  
Gerald Parolly ◽  
Anahit Khachatryan ◽  
Lusine Ghulikyan ◽  
Harutyun Sargsyan ◽  
...  
2019 ◽  
Vol 125 (3) ◽  
pp. 495-507 ◽  
Author(s):  
Francisco Balao ◽  
María Teresa Lorenzo ◽  
José Manuel Sánchez-Robles ◽  
Ovidiu Paun ◽  
Juan Luis García-Castaño ◽  
...  

Abstract Background and Aims Inferring the evolutionary relationships of species and their boundaries is critical in order to understand patterns of diversification and their historical drivers. Despite Abies (Pinaceae) being the second most diverse group of conifers, the evolutionary history of Circum-Mediterranean firs (CMFs) remains under debate. Methods We used restriction site-associated DNA sequencing (RAD-seq) on all proposed CMF taxa to investigate their phylogenetic relationships and taxonomic status. Key Results Based on thousands of genome-wide single nucleotide polymorphisms (SNPs), we present here the first formal test of species delimitation, and the first fully resolved, complete species tree for CMFs. We discovered that all previously recognized taxa in the Mediterranean should be treated as independent species, with the exception of Abies tazaotana and Abies marocana. An unexpectedly early pulse of speciation in the Oligocene–Miocene boundary is here documented for the group, pre-dating previous hypotheses by millions of years, revealing a complex evolutionary history encompassing both ancient and recent gene flow between distant lineages. Conclusions Our phylogenomic results contribute to shed light on conifers’ diversification. Our efforts to resolve the CMF phylogenetic relationships help refine their taxonomy and our knowledge of their evolution.


1995 ◽  
Vol 43 (2) ◽  
pp. 85-98 ◽  
Author(s):  
Adina Breiman ◽  
Dan Graur

Many wild and cultivated wheat species are amphidiploid, i.e., they are polyploid species containing two or more distinct nuclear genomes, each with its own independent evolutionary history, but whose genetic behavior resembles that of diploids. Amphidiploidy has important evolutionary consequences in wheat. Since the beginning of this century different methods have been employed to identify the diploid donors of the coexisting genomes in the polyploids. To date, several of the genomic donors have been identified, and the search for the others has been narrowed down considerably. Molecular methodologies that are being increasingly used in studies aimed at reconstructing the evolutionary history of wheat species and their wild relatives have resolved many of the phylogenetic relationships among the various taxa.


2019 ◽  
Vol 286 (1895) ◽  
pp. 20182076 ◽  
Author(s):  
Dominic A. Evangelista ◽  
Benjamin Wipfler ◽  
Olivier Béthoux ◽  
Alexander Donath ◽  
Mari Fujita ◽  
...  

Phylogenetic relationships among subgroups of cockroaches and termites are still matters of debate. Their divergence times and major phenotypic transitions during evolution are also not yet settled. We addressed these points by combining the first nuclear phylogenomic study of termites and cockroaches with a thorough approach to divergence time analysis, identification of endosymbionts, and reconstruction of ancestral morphological traits and behaviour. Analyses of the phylogenetic relationships within Blattodea robustly confirm previously uncertain hypotheses such as the sister-group relationship between Blaberoidea and remaining Blattodea, and Lamproblatta being the closest relative to the social and wood-feeding Cryptocercus and termites. Consequently, we propose new names for various clades in Blattodea: Cryptocercus + termites = Tutricablattae; Lamproblattidae + Tutricablattae = Kittrickea; and Blattoidea + Corydioidea = Solumblattodea. Our inferred divergence times contradict previous studies by showing that most subgroups of Blattodea evolved in the Cretaceous, reducing the gap between molecular estimates of divergence times and the fossil record. On a phenotypic level, the blattodean ground-plan is for egg packages to be laid directly in a hole while other forms of oviposition, including ovovivipary and vivipary, arose later. Finally, other changes in egg care strategy may have allowed for the adaptation of nest building and other novelties.


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