Geographic variation in a widespread perennial weed, Rumex crispus. The relative amounts of genetic and environmentally induced variation among populations

1982 ◽  
Vol 60 (10) ◽  
pp. 1928-1937 ◽  
Author(s):  
L. Hume ◽  
P. B. Cavers
Keyword(s):  
Genetic Variation ◽  
North America ◽  
Genetic Heterogeneity ◽  
Local Level ◽  
Adaptive Strategy ◽  
Eastern North America ◽  
Rumex Crispus ◽  
Perennial Weed ◽  
Wide Range ◽  
The World

Populations of Rumex crispus were sampled from eastern North America and Europe. The relative amounts of genetic variation and plasticity were examined, using 58 plant characters. About 61% of the total variation occurring in the experimental plants was accounted for by plasticity. The remaining 26% and 13% occurred within populations and among widespread populations, respectively. At the local level, there was little difference between variation occurring within genotypes and that within families (between maternal siblings). This suggests that the species is predominantly inbreeding. The majority of genetic variation occurs within populations at both the local and species' range levels.It was concluded that the species has large amounts of both flexibility and genetic heterogeneity. This adaptive strategy enables the species to survive under a very wide range of environmental situations and largely accounts for its becoming one of the most widely distributed plants in the world.

scholarly journals A Review of North American Isoetes engelmannii (Isoetaceae) complex hybrids, including the description of I. × fernaldii, hyb. nov. and I. × karenae, hyb. nov.

Webbia ◽  
2020 ◽  
Vol 75 (1) ◽  
pp. 35-50 ◽  
Author(s):  
Daniel Francis Brunton ◽  
Paul Clayton Sokoloff
Keyword(s):  
North America ◽  
North American ◽  
Original Description ◽  
Eastern North America ◽  
Cytological Evidence ◽  
The World ◽  
In The Wild

The Isoetes engelmannii complex of eastern North America consists of 30 taxa including 13 named species. Nine of the 17 hybrids within the complex (the largest group of Isoetes hybrids in the world) have been formally described. Those named hybrids are reviewed here in light of recent additions to and enhancements of the morphological and cytological evidence employed in their original description. The pedigree of three of these, I. ×brittonii, I. ×bruntonii and I. ×carltaylorii, is updated and clarified. Formal descriptions are proposed for two additional taxa: I. ×fernaldii, hyb. nov. (I. engelmannii × I. hyemalis) and I. ×karenae, hyb. nov. (I. appalachiana × engelmannii). The potential for a further eight hybrid combinations to occur in the wild is also addressed.

Skating in the New World

2017 ◽  
Author(s):  
James R. Hines
Keyword(s):  
Eighteenth Century ◽  
North America ◽  
American Revolution ◽  
New World ◽  
East Coast ◽  
Eastern North America ◽  
Recreational Activity ◽  
Figure Skaters ◽  
The World ◽  
Important Center

This chapter discusses the development of skating in the New World. There is much evidence of skating activity throughout the Colonies in the years before the American Revolution. It was a recreational activity, with racing being especially popular, but as a discipline little is known about it. Bone skates as a practical solution for travel across frozen landscapes were discovered independently in various parts of the world. French trappers who worked in eastern North America learned from the Iroquois Indians the practice of tying bones to their feet to traverse frozen rivers. Thus, in North America as in Europe and Asia, skating on bones must have existed for thousands of years. Bladed skates, however, were probably unknown in the New World before the eighteenth century, perhaps introduced by British officers stationed in Nova Scotia following its seizure from the French in 1713. By the mid-eighteenth century, skating was practiced along the East Coast whenever ice was available. Philadelphia became skating's first important center and could boast of competent figure skaters.

Nineteenth-Century Arrow Wounds and Perceptions of Prehistoric Warfare

2005 ◽  
Vol 70 (1) ◽  
pp. 144-156 ◽  
Author(s):  
George R. Milner
Keyword(s):  
Nineteenth Century ◽  
North America ◽  
Papua New Guinea ◽  
American West ◽  
Intergroup Conflict ◽  
Eastern North America ◽  
Indian Wars ◽  
Bone Damage ◽  
The World ◽  
Ways Of Life

In recent years, prehistoric warfare has increasingly attracted the attention of archaeologists in North America, much like other parts of the world. Skeletons with several forms of trauma, including arrow wounds, are often used as evidence of intergroup conflict, although opinion is divided over what these casualties might mean in terms of the effect of warfare on everyday life. Information on 191 patients from the nineteenth-century Indian Wars in the American West indicates that only about one in three arrows damaged bone, and as many as one-half of wounded lived for months or years following their injuries. Arrow wound distributions vary among Indian Wars cases, modern Papua New Guinea patients, and prehistoric skeletons from eastern North America, in large part because of differences in how fighting was conducted. Despite arguments to the contrary, it is reasonable to infer that even low percentages of archaeological skeletons with distinctive conflict-related bone damage indicate that warfare must have had a perceptible impact on ways of life.

Erfassung der adaptiven genetischen Variation der Eiche im Hinblick auf den Klimawandel | Assessment of adaptive genetic variation in oaks with relation to climate change

2010 ◽  
Vol 161 (6) ◽  
pp. 216-222
Author(s):  
Oliver Gailing
Keyword(s):  
Climate Change ◽  
Genetic Variation ◽  
North America ◽  
Phenotypic Variation ◽  
Natural Populations ◽  
Genetic Adaptation ◽  
Adaptive Genetic Variation ◽  
Adaptation To Climate Change ◽  
Adaptive Traits ◽  
Wide Range

Climate change is projected to lead to a major reorganization of our forests. For example, higher annual mean temperatures, longer growth seasons and drier summers are predicted for many parts of central and southern Europe, and in North America. In order to understand the genetic adaptation to climate change we need a better understanding of the genetic regulation of key traits involved in tolerance of water and temperature stress. Oaks (Quercus spp.) are excellent model species to study the adaptation of forest trees to changing environments. They show a wide geographic distribution in Europe and in North America as dominant tree species in many forests growing under a wide range of climatic and edaphic conditions. With the availability of a growing amount of functional and expressional candidate genes we are now able to test the functional importance of genes by associating nucleotide variation in these genes with phenotypic variation in adaptive traits in segregating or natural populations. Studies trying to associate genetic variation with phenotypic variation in adaptive traits can be performed in full-sib families derived from controlled crosses (Quantitative Trait Loci [QTL] mapping) or in natural populations (association mapping). For several important adaptive traits QTL were mapped, the underlying genes have to be tested in natural populations. A future objective is to test whether genes that underlie phenotypic variation in adaptive traits are involved in local genetic adaptation and viability selection at the seedling stage, linked to reciprocal transplant experiments in order to assess the performance over climatic gradients.

scholarly journals The northernmost occurrence of Chelydra serpentina in the eastern US during the Pleistocene

2016 ◽  
Author(s):  
Chase Brownstein
Keyword(s):  
New Jersey ◽  
North America ◽  
Late Pleistocene ◽  
Ice Sheet ◽  
Eastern North America ◽  
Chelydra Serpentina ◽  
Turtle Species ◽  
Snapping Turtle ◽  
Caudal Vertebrae ◽  
Wide Range

The snapping turtle species Chelydra serpentina, which has a wide range across North America, is extremely tolerant to cold and even freezing conditions. Here, I describe a single caudal vertebrae referred to Chelydra serpentina from the Late Pleistocene of New Jersey which represents the northernmost known occurrence of the species in eastern North America and the closest known occurrence of the species to a glacier or ice sheet in the continent during the Pleistocene. The specimen, which was collected at Ramanessin Brook in Holmdel, New Jersey, affirms that the Pleistocene deposits which line the banks of the popular Cretaceous site are not taphonomically biased to preserving larger fossils and in the future may yield an assemblage of small vertebrates.

scholarly journals The northernmost occurrence of Chelydra serpentina in the eastern US during the Pleistocene

2016 ◽  
Author(s):  
Chase Brownstein
Keyword(s):  
New Jersey ◽  
North America ◽  
Late Pleistocene ◽  
Ice Sheet ◽  
Eastern North America ◽  
Chelydra Serpentina ◽  
Turtle Species ◽  
Snapping Turtle ◽  
Caudal Vertebrae ◽  
Wide Range

The snapping turtle species Chelydra serpentina, which has a wide range across North America, is extremely tolerant to cold and even freezing conditions. Here, I describe a single caudal vertebrae referred to Chelydra serpentina from the Late Pleistocene of New Jersey which represents the northernmost known occurrence of the species in eastern North America and the closest known occurrence of the species to a glacier or ice sheet in the continent during the Pleistocene. The specimen, which was collected at Ramanessin Brook in Holmdel, New Jersey, affirms that the Pleistocene deposits which line the banks of the popular Cretaceous site are not taphonomically biased to preserving larger fossils and in the future may yield an assemblage of small vertebrates.

scholarly journals Draft Genome Sequence of an Erwinia tracheiphila Isolate from an Infected Muskmelon (Cucumis melo)

2018 ◽  
Vol 7 (17) ◽  
Author(s):  
Lori R. Shapiro ◽  
Andres Andrade ◽  
Erin D. Scully ◽  
Jorge Rocha ◽  
Joseph N. Paulson ◽  
...  
Keyword(s):  
Genetic Variation ◽  
North America ◽  
Plant Pathogen ◽  
Cucumis Melo ◽  
Reference Genome ◽  
Draft Genome ◽  
Eastern North America ◽  
Erwinia Tracheiphila ◽  
Content Type ◽  
Bacterial Plant Pathogen

Erwinia tracheiphila is a bacterial plant pathogen emerging in eastern North America. To aid in understanding genetic variation within E. tracheiphila, here we sequence the first reference genome of an infected muskmelon (Cucumis melo).

The moss flora of the Gaspé Peninsula (Quebec, Canada): list of species and preliminary analysis

1988 ◽  
Vol 66 (9) ◽  
pp. 1780-1799 ◽  
Author(s):  
René J. Belland ◽  
Marc Favreau
Keyword(s):  
North America ◽  
Field Studies ◽  
Eastern North America ◽  
Western North America ◽  
Last Glaciation ◽  
Extensive Field ◽  
The World ◽  
First Time ◽  
Gaspe Peninsula ◽  
Gaspé Peninsula

Extensive field studies and evaluation of previously published reports reveal a moss flora of at least 310 species for the Gaspé Peninsula. Forty species are reported for the first time from the peninsula, and Brachythecium glaciale is new to Quebec. While the Gaspé flora cannot be considered a distinctive one within the Gulf of St. Lawrence region, the large number of rare species is significant. Their presence in the Gaspé can be attributed to the diverse geology and topography of the peninsula. The bulk of the moss flora is clearly of boreal affinity, but many species have temperate, montane, or arctic – alpine distributions. Of special interest is the large proportion of species with various types of disjunct distributions, either within eastern North America or to other parts of the world, especially western North America. Some patterns strongly support the idea of survival in refugia in the Gulf of St. Lawrence region during the last glaciation.

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