Phylogenetic relationships in two African Cedreloideae tree genera (Meliaceae) reveal multiple rain/dry forest transitions

2019 ◽  
Vol 37 ◽  
pp. 1-10 ◽  
Author(s):  
Franck K. Monthe ◽  
Jérémy Migliore ◽  
Jérôme Duminil ◽  
Gaël Bouka ◽  
Boris B. Demenou ◽  
...  
Keyword(s):  
Phylogenetic Relationships ◽  
Dry Forest ◽  
Forest Transitions

PHYLOGENETIC RELATIONSHIPS IN TRICHILIA (MELIACEAE) BASED ON RIBOSOMAL ITS SEQUENCES

Phytotaxa ◽  
2016 ◽  
Vol 259 (1) ◽  
pp. 6 ◽  
Author(s):  
JAMES J. CLARKSON ◽  
TERENCE D. PENNINGTON ◽  
MARK W. CHASE ◽  
GWILYM HAYNES ◽  
RACHEL ENGSTRAND ◽  
...  
Keyword(s):  
Phylogenetic Relationships ◽  
Internal Transcribed Spacer ◽  
Sequence Divergence ◽  
Its Region ◽  
Dry Forest ◽  
Forest Species ◽  
African Species ◽  
Seasonally Dry ◽  
Amazonian Rainforest ◽  
Seasonally Dry Forest

The internal transcribed spacer (ITS) region of ribosomal DNA (rDNA) was used to investigate phylogenetic relationships in Trichilia (Meliaceae). Analyses focused on the neotropical Trichilia and consisted of 112 accessions (95 neotropical Trichilia, 6 African Trichilia and 11 Meliaceae Outgroups). Bayesian and Parsimony approaches demonstrated that the Cuban species T. havenensis is the earliest diverging lineage in the genus. The African species of Trichilia are nested within the neotropical clade. Section Moschoxylun (primarily Amazonian rainforest species) shows significantly lower levels of sequence divergence than section Trichilia (primarily dry/ seasonally dry forest species). Recently diverged rainforest taxa have been documented in several other Angiosperm families and our results therefore confirm this phenomenon.

Architecture of Radiolitid Rudist (Mollusca) Shell-Wall Structures and its Phylogenetic Implications

1975 ◽  
Vol 33 ◽  
pp. 686-687
Author(s):  
David H. Sturm ◽  
Bob F. Perkins
Keyword(s):  
Phylogenetic Relationships ◽  
Outer Wall ◽  
Shell Microstructure ◽  
Shell Wall ◽  
Wall Structures ◽  
Phylogenetic Implications ◽  
Cellular Wall ◽  
Superfamily Analysis ◽  
Central Texas

Each of the seven families of rudists (Mollusca, Bivalvia, Hippuritacea) is characterized by distinctive shell-wall architectures which reflect phylogenetic relationships within the superfamily. Analysis of the complex, calcareous, cellular wall of the attached valve of the radiolite rudist Eoradiolites davidsoni (Hill) from the Comanche Cretaceous of Central Texas indicates that its wall architecture is an elaboration of the simpler monopleurid rudist wall and supports possible radiolite-monopleurid relationships.Several well-preserved specimens of E. davidsoni were sectioned, polished, etched, and carbon and gold coated for SEM examination. Maximum shell microstructure detail was displayed by etching with a 0.7% HC1 solution from 80 to 100 seconds.The shell of E. davidsoni comprises a large, thick-walled, conical, attached valve (AV) and a small, very thin, operculate, free valve (FV) (Fig. 1a). The AV shell is two-layered with a thin inner wall, in which original structures are usually obliterated by recrystallization, and a thick, cellular, outer wall.

Phylogenetic relationships ofSalvia(Lamiaceae) in China: Evidence from DNA sequence datasets

2012 ◽  
pp. n/a-n/a
Author(s):  
Qian-Quan Li ◽  
Min-Hui Li ◽  
Qing-Jun Yuan ◽  
Zhan-Hu Cui ◽  
Lu-Qi Huang ◽  
...  
Keyword(s):  
Dna Sequence ◽  
Phylogenetic Relationships

Land Use Change and Commodity Frontiers

2020 ◽  
Vol 4 (1) ◽  
Author(s):  
Daniel M. Cáceres ◽  
Esteban Tapella ◽  
Diego A. Cabrol ◽  
Lucrecia Estigarribia
Keyword(s):  
Large Scale ◽  
Field Work ◽  
Dry Forest ◽  
Social Actors ◽  
Goods And Services ◽  
Fast Pace ◽  
Forest Use ◽  
The Government ◽  
Social Environmental ◽  
Management Recommendations

Argentina is experiencing an expansion of soya and maize cultivation that is pushing the agricultural frontier over areas formerly occupied by native Chaco forest. Subsistance farmers use this dry forest to raise goats and cattle and to obtain a broad range of goods and services. Thus, two very different and non-compatible land uses are in dispute. On the one hand subsistance farmers fostering an extensive and diversified forest use, on the other hand, large-scale producers who need to clear out the forest to sow annual crops in order to appropriate soil fertility. First, the paper looks at how these social actors perceive Chaco forest, what their interests are, and what kind of values they attach to it. Second, we analyze the social-environmental conflicts that arise among actors in order to appropriate forest’s benefits. Special attention is paid to the role played by the government in relation to: (a) how does it respond to the demands of the different sectors; and (b) how it deals with the management recommendations produced by scientists carrying out social and ecological research. To put these ideas at test we focus on a case study located in Western Córdoba (Argentina), where industrial agriculture is expanding at a fast pace, and where social actors’ interests are generating a series of disputes and conflicts. Drawing upon field work, the paper shows how power alliances between economic and political powers, use the institutional framework of the State in their own benefit, disregarding wider environmental and social costs. 

Systematics of Hymenophyllum subgenus Mecodium (Hymenophyllaceae) in Taiwan

2019 ◽  
Vol 44 (4) ◽  
pp. 753-767
Author(s):  
Tian-Chuan Hsu ◽  
Yu-Fang Huang ◽  
Yi-Shan Chao
Keyword(s):  
Phylogenetic Relationships ◽  
The Philippines ◽  
Common Element ◽  
Morphological Investigation ◽  
Eastern Asia ◽  
Type Specimens ◽  
The Status ◽  
Molecular Phylogenetic ◽  
A New Species ◽  
Independent Species

Abstract—Hymenophyllum subg. Mecodium, composed of the taxonomically notorious H. polyanthos and approximately 15 other closely related taxa, is a common element of filmy fern communities in the tropical and subtropical moist forests. In Taiwan, although only H. polyanthos and one or two closely related taxa were recognized in recent studies, considerable morphological variation has been observed among populations throughout the island. Thus, we conducted an extensive morphological investigation, as well as a molecular phylogenetic analysis, to clarify the specific diversity and phylogenetic relationships within Hymenophyllum subg. Mecodium in Taiwan. Field and herbaria surveys helped in recognizing five morphs in Taiwan, mainly differentiated by the combination of certain traits, viz., the presence or absence of stipe wings, general frond size and shape, degree of laminar crispation, sori position, and involucre shape. The different morphs had diverse ecological preferences. The phylogenetic tree, inferred from the sequences of the plastid loci rbcL and rps4-trnS, demonstrated that Hymenophyllum subg. Mecodium materials in Taiwan comprise several well-supported lineages, mostly corresponding to the classification based on morphology. Comparing with the protologues and type specimens of 34 related scientific names, the five morphs are herein recognized as five independent species. A new species, Hymenophyllum exquisitum, is described here. Also, the status of H. paniculiflorum is reconfirmed and that of H. fujisanense, H. parallelocarpum, and H. punctisorum reinstated. Only H. exquisitum and H. parallelocarpum are endemic to Taiwan among all the species studied. In addition, the names Hymenophyllum blumeanum, H. integrum, H. microsorum, H. polyanthos, H. tenellum, and H. wrightii are now excluded from the regional flora, and several related taxa from China, Taiwan, and the Philippines are treated as synonyms. This study unravels the deep phylogenetic relationships within Hymenophyllum subg. Mecodium in Taiwan and Eastern Asia.

Readjustment of the Standard ASUDAS to Encompass Dental Morphological Variations in Plio-Pleistocene Hominins

2018 ◽  
Vol 30 (1-2) ◽  
pp. 32-48
Author(s):  
M. Louail ◽  
S. Prat
Keyword(s):  
Phylogenetic Relationships ◽  
Homo Sapiens ◽  
Initial Study ◽  
Morphological Characters ◽  
State University ◽  
Arizona State University ◽  
Dental Anthropology ◽  
Morphological Variations ◽  
Fossil Hominins ◽  
Fossil Hominin

The standard ASUDAS scoring system (Arizona State University Dental Anthropology System) is used to assess dental morphological variations in modern humans. It is also frequently used to study, score, and compare morphological variations in fossil hominin taxa and to examine their phylogenetic relationships. However, using ASUDAS in studies of this type is under debate because it is based on modern Homo sapiens populations and does not appear to cover all variations observed in fossil Plio-Pleistocene homi- nins. Our observations and coding of 178 dentals casts of Plio-Pleistocene specimens based on ASUDAS and from the literature have confirmed the need to adapt the standard system to fossil hominins. In this initial study, we propose that the scoring procedures for some morphological characters need to be readjusted, while others could be standardized following the ASUDAS system.

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