scholarly journals Evolutionary Relationships among the North American Mallards

The Auk ◽  
1961 ◽  
Vol 78 (1) ◽  
pp. 3-43 ◽  
Author(s):  
Paul A. Johnsgard
Keyword(s):  
North American ◽  
Evolutionary Relationships ◽  
The North

Population structure of Heterobasidion annosum from North America and Europe

1993 ◽  
Vol 71 (8) ◽  
pp. 1064-1071 ◽  
Author(s):  
William J. Otrosina ◽  
Thomas E. Chase ◽  
Fields W. Cobb Jr. ◽  
Kari Korhonen
Keyword(s):  
Population Structure ◽  
North America ◽  
North American ◽  
Forest Tree ◽  
Heterobasidion Annosum ◽  
Evolutionary Relationships ◽  
The North ◽  
Isozyme Loci ◽  
Intersterility Groups ◽  
European Populations

Isolates of Heterobasidion annosum (Fr.) Bref. representing North American S and P and European S, P, and F intersterility groups were subjected to isozyme analysis. European S, P, and F groups had more variability than the North American S and P groups in expected hterozygosity, number of alleles per locus, and percent polymorphic loci. In contrast with the North American S and P groups, the European intersterility groups could not be distinguished from each other on the basis of individual isozyme loci, although significant differences in allele frequencies exist between European S and P groups. This suggests that evolution proceeded at different rates in the intersterility groups, or intersterility barriers appeared later in the European populations relative to the North American populations of H. annosum. Changes in climate and host species associations during the Tertiary may have been a major factor in evolution of H. annosum intersterility groups. Key words: allozymes, forest tree hosts, playnological events, evolutionary relationships, Hymenomycetes, root disease.

Evolutionary relationships in Oxytropis species, as estimated from the nuclear ribosomal internal transcribed spacer (ITS) sequences point to multiple expansions into the Arctic

Botany ◽  
2012 ◽  
Vol 90 (8) ◽  
pp. 770-779 ◽  
Author(s):  
Annie Archambault ◽  
Martina V. Strömvik
Keyword(s):  
North American ◽  
Internal Transcribed Spacer ◽  
Phylogenetic Trees ◽  
Its Region ◽  
Its Sequences ◽  
The Arctic ◽  
Evolutionary Relationships ◽  
Data Set ◽  
The North ◽  
North American Arctic

Species of the genus Oxytropis are distributed in the northern hemisphere, especially in alpine and arctic areas. Although comprehensive taxonomic treatments exist for local floras, an understanding of the evolutionary relationships is lacking for the genus as a whole. To determine if different ancestral Oxytropis species colonized the North American Arctic separately, as suggested by taxonomy, we sequenced the nuclear ribosomal internal transcribed spacer (ITS) region from 16 Oxytropis specimens, including four species that were used in a previous transcriptome study. In addition, 81 other Oxytropis ITS sequences were retrieved from public sequence databases and included in the analysis. The whole data set was analyzed using phylogenetic trees and statistical parsimony networks. Results show that all Oxytropis ITS sequences are very similar. Furthermore, at least six lineages evolved from different temperate ancestors to colonize the North American Arctic. This pattern is believed to be typical of the arctic flora. Additionally, the sequence relationship analyses confirm that the subgenus Phacoxytropis may be ancestral in Oxytropis.

Phylogeny of Gremmeniella spp. based on sequences of the 5.8S rDNA and internal transcribed spacer region

1997 ◽  
Vol 75 (5) ◽  
pp. 693-698 ◽  
Author(s):  
Richard C. Hamelin ◽  
Jimmy Rail
Keyword(s):  
North American ◽  
Internal Transcribed Spacer ◽  
Host Specialization ◽  
Evolutionary Relationships ◽  
Abies Sachalinensis ◽  
Internal Transcribed Spacer Region ◽  
5.8S Rdna ◽  
Asian Race ◽  
The North ◽  
Distance Methods

Sequences in the 5.8S rDNA and internal transcribed spacer region were obtained for taxa belonging to Gremmeniella spp., and a phylogenetic analysis was carried out using parsimony and distance methods. A set of hypotheses concerning evolutionary relationships between members of that genus was tested. The hypothesis that all members of Gremmeniella abietina var. abietina are closely related was rejected. It appears that the Asian race is quite divergent from the European and North American races, but could be more closely related to G. abietina var. balsamea. The phylogeny was consistent with host specificity: members of G. abietina var. abietina generally do not infect Abies or Picea spp. but the Asian race occurs on Abies sachalinensis in Japan. The hypothesis that host specialization has created divergence within G. abietina var. balsamea was supported by our analysis because the levels of divergence between isolates originating from Picea spp. and Abies spp. were similar to those found between the North American and European races of G. abietina var. abietina. The hypothesis that greater divergence occurred between Gremmeniella abietina and Gremmeniella laricina than between G. abietina var. abietina and G. abietina var. balsamea was not supported. The level of divergence was as large between the two varieties within G. abietina as between the two species G. abietina and G. laricina. These results indicate that similar taxonomic levels should be applied to these three taxa. Key words: scleroderris canker, internal transcribed spacer (ITS).

Phylogeny of Braya and Neotorularia (Brassicaceae) based on nuclear ribosomal internal transcribed spacer and chloroplast trnL intron sequences

2004 ◽  
Vol 82 (3) ◽  
pp. 376-392 ◽  
Author(s):  
Suzanne I Warwick ◽  
Ihsan A Al-Shehbaz ◽  
Connie Sauder ◽  
James G Harris ◽  
Marcus Koch
Keyword(s):  
North American ◽  
Maximum Parsimony ◽  
Internal Transcribed Spacer ◽  
Sequence Data ◽  
Its Region ◽  
Molecular Data ◽  
Its Sequences ◽  
Evolutionary Relationships ◽  
Trnl Intron ◽  
The North

Sequence data from the nuclear ribosomal internal transcribed spacer (ITS) region and the chloroplast trnL intron were used to examine the evolutionary relationships and generic delimitations of Braya, Neotorularia, Dichasianthus, and Sisymbriopsis. Several species, especially the North American - Asian Braya (= Neotorularia) humilis (C.A. Mey.) B.L. Rob., were previously assigned to more than one genus. Sequence data were obtained from all Braya species, except Braya pilosa Hook., seven species of Neotorularia, one of Dichasianthus, and two of Sisymbriopsis. Maximum parsimony analyses showed a poly phyletic origin for Neotorularia, with the genus split into three or four major clades. For both the ITS and trnL sequence data, three species (Neotorularia brachycarpa (Vassilcz.) Hedge & J. Léonard, Neotorularia gamosepala (Hedge) O'Kane & Al-Shehbaz, and Neotorularia humilis (C.A. Mey.) Hedge & J. Léonard) fell within the Braya clade; Neotorularia korolkowii (Regel & Schmalh.) Hedge & J. Léonard formed a separate clade with Dichasianthus subtilissimus (Popov) Ovcz. & Yunussov, while Neotorularia torulosa (Desf.) Hedge & J. Léonard, Neotorularia contor tuplicata (Stephan ex Willd.) Hedge & J. Léonard, Neotorularia dentata (Freyn & Sint.) Hedge & J. Léonard, and Neotorularia tetracmoides (Boiss. & Hausskn.) Hedge & J. Léonard formed either one clade (trnL data) or two clades (ITS data). Sisymbriopsis was not monophyletic, although ITS and trnL data showed a weakly supported relationship between Sisymbriopsis mollipila (Maxim.) Botsch. and one of the Neotorularia clades. Except for Braya forrestii W.W. Sm., which is well supported as sister to the remainder of the Braya clade (ITS data), ITS and trnL sequences showed poor resolution within Braya. Additive ITS sequences indicated allopolyploid origins for Braya fernaldii Abbe, Braya longii Fernald, and three accessions of Braya glabella Richardson (all species with 2n = 56). Morphology and molecular data strongly suggest expanding Braya to include N. humilis, N. brachycarpa, and N. gamosepala; delimiting Neotorularia to include N. torulosa, N. contortuplicata, N. dentata, N. korolkowii, N. tetracmoides, D. subtilissimus, and S. mollipila; and revising Sisymbriopsis.Key words: Braya, Neotorularia, Dichasianthus, Sisymbriopsis, ITS, trnL, Brassicaceae.

1588: The Bicalutamide Early Prostate Cancer Program: Findings of the North American Trial at 7.7 Years' Median Follow-Up

2006 ◽  
Vol 175 (4S) ◽  
pp. 511-512
Author(s):  
David G. McLeod ◽  
Ira Klimberg ◽  
Donald Gleason ◽  
Gerald Chodak ◽  
Thomas Morris ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
North American ◽  
Early Prostate Cancer ◽  
The North ◽  
Cancer Program
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