Species divergence and repeated ancient hybridization in a Sulawesian lake system

Author(s):  
Ixchel F. Mandagi ◽  
Ryo Kakioka ◽  
Javier Montenegro ◽  
Hirozumi Kobayashi ◽  
Kawilarang W. A. Masengi ◽  
...  
2019 ◽  
Vol 44 (4) ◽  
pp. 930-942
Author(s):  
Geraldine A. Allen ◽  
Luc Brouillet ◽  
John C. Semple ◽  
Heidi J. Guest ◽  
Robert Underhill

Abstract—Doellingeria and Eucephalus form the earliest-diverging clade of the North American Astereae lineage. Phylogenetic analyses of both nuclear and plastid sequence data show that the Doellingeria-Eucephalus clade consists of two main subclades that differ from current circumscriptions of the two genera. Doellingeria is the sister group to E. elegans, and the Doellingeria + E. elegans subclade in turn is sister to the subclade containing all remaining species of Eucephalus. In the plastid phylogeny, the two subclades are deeply divergent, a pattern that is consistent with an ancient hybridization event involving ancestral species of the Doellingeria-Eucephalus clade and an ancestral taxon of a related North American or South American group. Divergence of the two Doellingeria-Eucephalus subclades may have occurred in association with northward migration from South American ancestors. We combine these two genera under the older of the two names, Doellingeria, and propose 12 new combinations (10 species and two varieties) for all species of Eucephalus.


2016 ◽  
Author(s):  
Anna Sofia Andeskie ◽  
◽  
Kathleen C. Benison ◽  
Lynnette A. Eichenlaub

2017 ◽  
Author(s):  
Judith Totman Parrish ◽  
◽  
Ethan G. Hyland ◽  
Marjorie A. Chan ◽  
Stephen T. Hasiotis ◽  
...  

Genetics ◽  
2003 ◽  
Vol 164 (4) ◽  
pp. 1645-1656 ◽  
Author(s):  
Bruce Rannala ◽  
Ziheng Yang

Abstract The effective population sizes of ancestral as well as modern species are important parameters in models of population genetics and human evolution. The commonly used method for estimating ancestral population sizes, based on counting mismatches between the species tree and the inferred gene trees, is highly biased as it ignores uncertainties in gene tree reconstruction. In this article, we develop a Bayes method for simultaneous estimation of the species divergence times and current and ancestral population sizes. The method uses DNA sequence data from multiple loci and extracts information about conflicts among gene tree topologies and coalescent times to estimate ancestral population sizes. The topology of the species tree is assumed known. A Markov chain Monte Carlo algorithm is implemented to integrate over uncertain gene trees and branch lengths (or coalescence times) at each locus as well as species divergence times. The method can handle any species tree and allows different numbers of sequences at different loci. We apply the method to published noncoding DNA sequences from the human and the great apes. There are strong correlations between posterior estimates of speciation times and ancestral population sizes. With the use of an informative prior for the human-chimpanzee divergence date, the population size of the common ancestor of the two species is estimated to be ∼20,000, with a 95% credibility interval (8000, 40,000). Our estimates, however, are affected by model assumptions as well as data quality. We suggest that reliable estimates have yet to await more data and more realistic models.


2013 ◽  
Vol 27 (7) ◽  
pp. 2657-2670 ◽  
Author(s):  
A. M. Sheela ◽  
J. Letha ◽  
Joseph Sabu ◽  
K. K. Ramachandran ◽  
J. Justus

2014 ◽  
Vol 70 ◽  
pp. 1-12 ◽  
Author(s):  
J. Susanne Hauswaldt ◽  
Claudio Angelini ◽  
Marcelo Gehara ◽  
Edgar Benavides ◽  
Andy Polok ◽  
...  

Homeopathy ◽  
2020 ◽  
Vol 109 (03) ◽  
pp. 126-132
Author(s):  
Ana Carla C. Aparicio ◽  
Larissa Helen S. de Oliveira ◽  
Jefferson S. Silva ◽  
Cideli P. Coelho ◽  
Sonia Regina Pinheiro ◽  
...  

Abstract Background Highly diluted and succussed solutions interact with solvatochromic dyes, indicating that changes in solvent and solute polarity could be related to their mechanism of action. It is not known, however, how the activity associated with succussed high dilutions is transferred to untreated water and what the limits of this process are. Aims The aims of the present study were to ascertain whether a succussed high dilution of phosphorus (1.5 × 1−59 M; Phos 30cH) seeded into a natural water source that fed a fjord and two connected lakes could propagate itself through the lake system (total volume 2200 m3) and, moreover, whether the process could be tracked using solvatochromic dyes. Methods Samples of water were collected before and after seeding, at different times and places throughout the lake system. Controls comprised water taken from an untreated and adjacent, but independent, lake (1385 m3). Results Water samples taken up to 72 hours after the source treatment produced significant increases (p ≤ 0.03) in the absorbance of the solvatochromic dye methylene violet (MV), while samples from the control lake produced no changes. Conclusions The study indicates that activity associated with Phos 30c can propagate itself through large volumes of water, causing changes throughout a whole connected lake system, and that these changes can be tracked using the solvatochromic dye MV. This in turn means the use of homeopathic medicines in large volumes of drinking water, in farming and ecological contexts, now has the potential to be assessed with physico-chemical monitoring.


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