Evolutionary significance of exine ultrastructure in the subfamily Barnadesioideae (Asteraceae) in the light of molecular phylogenetics

2015 ◽  
Vol 221 ◽  
pp. 32-46 ◽  
Author(s):  
María C. Tellería ◽  
Luis Palazzesi ◽  
Viviana Barreda
2021 ◽  
Vol 5 (1) ◽  
pp. 141-150
Author(s):  
Gaurang G. Gowande ◽  
Harshal S. Bhosale ◽  
Pushkar U. Phansalkar ◽  
Mandar Sawant ◽  
Zeeshan A. Mirza

The montane agamid species Pseudocalotes austeniana has had a complicated taxonomic history, as the species was initially described as a member of the genus Salea Gray, 1845. Later, the species was placed in a monotypic genus Mictopholis Smith, 1935, which was erected only to include this species; however, the species was later on transferred to the genus Pseudocalotes Fitzinger, 1843, owing to the morphological similarities, and lack of strong characters to diagnose the genus Mictopholis. Nonetheless, its precise phylogenetic and systematic position has remained unresolved due to the lack of molecular sequence data. During a herpetological expedition to Arunachal Pradesh, specimens of P. austeniana were collected from the hills near the type locality. The mitochondrial 16S rRNA, ND2 and ND4, and the nuclear RAG1 regions were subjected to molecular phylogenetics. Maximum Likelihood and Bayesian Inference gene trees revealed that P. austeniana is a member of the subfamily Draconinae. The analyses showed that the genus Pseudocalotes is polyphyletic, and P. austeniana was embedded within the genus Japalura Gray, 1853 sensu stricto. We here, thus, propose to transfer the species P. austeniana to the genus Japlaura, as Japalura austenianacomb. nov. Biogeographic and evolutionary significance of the findings are discussed.


2020 ◽  
Author(s):  
Natalia Tkach ◽  
Marcin Nobis ◽  
Julia Schneider ◽  
Hannes Becher ◽  
Grit Winterfeld ◽  
...  

ABSTRACTThe mainly Australian grass genus Austrostipa with ca. 64 species represents a remarkable example of an evolutionary radiation. To investigate aspects of diversification, macro- and micromorphological variation in this genus we conducted a molecular phylogenetic and scanning electron microscopy (SEM) analysis including representatives from all of its accepted subgenera.Plastid DNA variation within Austrostipa was low and only few lineages were resolved. Nuclear ITS and Acc1 yielded comparable groupings of taxa and resolved subgenera Arbuscula, Petaurista, Bambusina in a common clade and as monophyletic. In summary, we suggest recognizing nine subgenera in Austrostipa.Because of its taxonomic significance in Stipeae, we studied the lemma epidermal structure in 34 representatives of Austrostipa. In most species, the lemma epidermal pattern (LEP) was relatively uniform (maize-like LEP), but in six species it was more similar to that of Stipa s.str., Neotrinia, Ptilagrostis and Orthoraphium. The species representing subgenera Lobatae, Petaurista, Bambusina and A. muelleri from subg. Tuberculatae were well-separated from all the other species included in the analysis.Two different sequence copies of Acc1 were found in polyploid Austrostipa and Anemanthele. Each of the copy types formed a single clade. This was also true of the sampled species of Stipa s.str., but their clades were strongly separated from those of Austrostipa and Anemanthele. This underlines the statement of Tzvelev (1977) that most if not all contemporary Stipeae are of hybrid origin and demonstrates it for the first time unambiguously on the molecular level.Chromosome number variation is surveyed and reviewed for the whole tribe Stipeae and interpreted in a molecular phylogenetic framework. The rather coherent picture of chromosome number variation underlines the phylogenetic and evolutionary significance of this character.The closest extant relatives of Austrostipa and Anemanthele are in the clade of Achnatherum s.str., Celtica, Oloptum and Stipellula. These genera are most abundant in Central and Eastern Asia, which makes a colonization of Australian and New Zealand from this region more likely, perhaps via long-distance dispersal, than colonization of Australia from southern South America via Antarctica as previously invoked.Supporting Information may be found online in the Supporting Information section at the end of the article.


2021 ◽  
Vol 11 ◽  
Author(s):  
Natalia Tkach ◽  
Marcin Nobis ◽  
Julia Schneider ◽  
Hannes Becher ◽  
Grit Winterfeld ◽  
...  

The mainly Australian grass genus Austrostipa (tribe Stipeae) comprising approximately 64 species represents a remarkable example of an evolutionary radiation. To investigate aspects of diversification, macro- and micromorphological variation in this genus, we conducted molecular phylogenetic and scanning electron microscopy (SEM) analyses including representatives from most of Austrostipa’s currently accepted subgenera. Because of its taxonomic significance in Stipeae, we studied the lemma epidermal pattern (LEP) in 34 representatives of Austrostipa. Plastid DNA variation within Austrostipa was low and only few lineages were resolved. Nuclear ITS and Acc1 yielded comparable groupings of taxa and resolved subgenera Arbuscula, Petaurista, and Bambusina in a common clade and as monophyletic. In most of the Austrostipa species studied, the LEP was relatively uniform (typical maize-like), but six species had a modified cellular structure. The species representing subgenera Lobatae, Petaurista, Bambusina as well as A. muelleri from subg. Tuberculatae were well-separated from all the other species included in the analysis. We suggest recognizing nine subgenera in Austrostipa (with number of species): Arbuscula (4), Aulax (2), Austrostipa (36), Bambusina (2), Falcatae (10), Lobatae (5), Longiaristatae (2), Petaurista (2) and the new subgenus Paucispiculatae (1) encompassing A. muelleri. Two paralogous sequence copies of Acc1, forming two distinct clades, were found in polyploid Austrostipa and Anemanthele. We found analogous patterns for our samples of Stipa s.str. with their Acc1 clades strongly separated from those of Austrostipa and Anemanthele. This underlines a previous hypothesis of Tzvelev (1977) that most extant Stipeae are of hybrid origin. We also prepared an up-to-date survey and reviewed the chromosome number variation for our molecularly studied taxa and the whole tribe Stipeae. The chromosome base number patterns as well as dysploidy and whole-genome duplication events were interpreted in a phylogenetic framework. The rather coherent picture of chromosome number variation underlines the enormous phylogenetic and evolutionary significance of this frequently ignored character.


Planta Medica ◽  
2016 ◽  
Vol 81 (S 01) ◽  
pp. S1-S381 ◽  
Author(s):  
M Ernst ◽  
CH Saslis-Lagoudakis ◽  
OM Grace ◽  
N Nilsson ◽  
H Toft Simonsen ◽  
...  

2019 ◽  
Vol 52 (3) ◽  
Author(s):  
K. Izbastina ◽  
M. Kurmanbayeva ◽  
A. Bazargaliyeva ◽  
N. Ablaikhanova ◽  
Z. Inelova ◽  
...  

Author(s):  
Francisco J. Ayala ◽  
Camilo J. Cela-Conde

This chapter analyzes the transition of the hominins from the Middle Pleistocene to the Late Pleistocene. Two alternative models are explored, the “Multiregional Hypothesis” (MH) and the “Replacement Hypothesis,” and how each model evaluates the existing relationships between the taxa Homo neanderthalensis and Homo sapiens. Next is the investigation of the transitional (or “archaic,” if this grade is taken into account) exemplars found in Europe, Africa, and Asia and their evolutionary significance. In particular, the comparison between H. erectus and H. sapiens in China and Java is investigated, as the main foundation of the MH. The chapter ends with the surprising discovery of Homo floresiensis and its description and interpretations concerning its taxonomic and phylogenetic significance. The correlation between brain development and technological progress is at odds with the attribution of perforators, microblades, and fishing hooks to a hominin with a small cranial volume, similar to that of Australopithecus afarensis.


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