scholarly journals Phylogeny, biogeography and diversification patterns of side-necked turtles (Testudines: Pleurodira)

2018 ◽  
Vol 5 (3) ◽  
pp. 171773 ◽  
Author(s):  
Gabriel S. Ferreira ◽  
Mario Bronzati ◽  
Max C. Langer ◽  
Juliana Sterli
Keyword(s):  
North America ◽  
South America ◽  
Evolutionary History ◽  
Mass Extinctions ◽  
Phylogenetic Hypothesis ◽  
Widespread Distribution ◽  
The Past ◽  
Biogeographic History ◽  
Dispersal Events ◽  
Freshwater Environments

Pleurodires or side-necked turtles are today restricted to freshwater environments of South America, Africa–Madagascar and Australia, but in the past they were distributed much more broadly, being found also on Eurasia, India and North America, and marine environments. Two hypotheses were proposed to explain this distribution; in the first, vicariance would have shaped the current geographical distribution and, in the second, extinctions constrained a previously widespread distribution. Here, we aim to reconstruct pleurodiran biogeographic history and diversification patterns based on a new phylogenetic hypothesis recovered from the analysis of the largest morphological dataset yet compiled for the lineage, testing which biogeographical process prevailed during its evolutionary history. The resulting topology generally agrees with previous hypotheses of the group and shows that most diversification shifts were related to the exploration of new niches, e.g. littoral or marine radiations. In addition, as other turtles, pleurodires do not seem to have been much affected by either the Cretaceous–Palaeogene or the Eocene–Oligocene mass extinctions. The biogeographic analyses highlight the predominance of both anagenetic and cladogenetic dispersal events and support the importance of transoceanic dispersals as a more common driver of area changes than previously thought, agreeing with previous studies with other non-turtle lineages.

Certeau, Michel de (1925–86)

2018 ◽  
Author(s):  
Tom Conley
Keyword(s):  
North America ◽  
South America ◽  
Social Practice ◽  
The Other ◽  
General Philosophy ◽  
Late Medieval ◽  
The Past ◽  
Michel De Certeau ◽  
History Of ◽  
Strategic Policies

Michel de Certeau, a French philosopher trained in history and ethnography, was a peripatetic teacher in Europe, South America and North America. His thought has inflected four areas of philosophy. He studied how mysticism informs late-medieval epistemology and social practice. With the advent of the Scientific Revolution, the affinities the mystic shares with nature and the cosmos become, like religion itself, repressed or concealed. An adjunct discipline, heterology, thus constitutes an anthropology of alterity, studying the ‘other’ and the destiny of religion since the sixteenth century. De Certeau opens the hidden agendas that make representations of the past a function of social pressures, so that sometime histories are rearticulated in mirrored or subversive forms. This subversion makes accessible a general philosophy of invention that works within and against the strategic policies of official institutions. De Certeau’s writings also belong to activism, the history of ideological structures, psychoanalysis, and post-1968 theories of writing (écriture) as defined by Deleuze, Derrida, Foucault and Lyotard.

scholarly journals International increase in Salmonella enteritidis: A new pandemic?

1990 ◽  
Vol 105 (1) ◽  
pp. 21-27 ◽  
Author(s):  
D. C. Rodrigue ◽  
R. V. Tauxe ◽  
B. Rowe
Keyword(s):  
North America ◽  
South America ◽  
Atlantic Ocean ◽  
Salmonella Enteritidis ◽  
European Countries ◽  
The Past ◽  
America South ◽  
Global Increase ◽  
Salmonella Serotype ◽  
Reported Data

SUMMARYOver the past 5 years Salmonella enteritidis infections in humans have increased on both sides of the Atlantic ocean. The WHO salmonella surveillance data for 1979–87 were reviewed and show that S. enteritidis appears to be increasing on at least the continents of North America, South America, and Europe, and may include Africa. S. enteritidis isolates increased in 24 (69%) of 35 countries between 1979 and 1987. In 1979, only 2 (10%) of 21 countries with reported data reported S. enteritidis as their most common salmonella serotype; in 1987, 9 (43%) of 21 countries reported S. enteritidis as their most common serotype; 8 (89 %) of 9 were European countries. Although the reason for the global increase is not yet clear, investigations in individual countries suggest it is related to consumption of eggs and poultry which harbour the organism.

scholarly journals Aerobic bacterial methane synthesis

2021 ◽  
Vol 118 (27) ◽  
pp. e2019229118
Author(s):  
Qian Wang ◽  
Abdullah Alowaifeer ◽  
Patricia Kerner ◽  
Narayanaganesh Balasubramanian ◽  
Angela Patterson ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Surface Waters ◽  
National Park ◽  
Strictly Anaerobic ◽  
Yellowstone Lake ◽  
Widespread Distribution ◽  
Biogenic Methane ◽  
Sources And Sinks ◽  
The Past ◽  
Freshwater Environments

Reports of biogenic methane (CH4) synthesis associated with a range of organisms have steadily accumulated in the literature. This has not happened without controversy and in most cases the process is poorly understood at the gene and enzyme levels. In marine and freshwater environments, CH4 supersaturation of oxic surface waters has been termed the “methane paradox” because biological CH4 synthesis is viewed to be a strictly anaerobic process carried out by O2-sensitive methanogens. Interest in this phenomenon has surged within the past decade because of the importance of understanding sources and sinks of this potent greenhouse gas. In our work on Yellowstone Lake in Yellowstone National Park, we demonstrate microbiological conversion of methylamine to CH4 and isolate and characterize an Acidovorax sp. capable of this activity. Furthermore, we identify and clone a gene critical to this process (encodes pyridoxylamine phosphate-dependent aspartate aminotransferase) and demonstrate that this property can be transferred to Escherichia coli with this gene and will occur as a purified enzyme. This previously unrecognized process sheds light on environmental cycling of CH4, suggesting that O2-insensitive, ecologically relevant aerobic CH4 synthesis is likely of widespread distribution in the environment and should be considered in CH4 modeling efforts.

scholarly journals The systematic relationships and biogeographic history of ornithischian dinosaurs

PeerJ ◽  
2015 ◽  
Vol 3 ◽  
pp. e1523 ◽  
Author(s):  
Clint A. Boyd
Keyword(s):  
North America ◽  
South America ◽  
Wide Distribution ◽  
Sister Taxon ◽  
Evolutionary Patterns ◽  
Biogeographic History ◽  
Early Diversification ◽  
Systematic Relationships ◽  
Patterns And Processes ◽  
Comprehensive Framework

The systematic relationships of taxa traditionally referred to as ‘basal ornithopods’ or ‘hypsilophodontids’ remain poorly resolved since it was discovered that these taxa are not a monophyletic group, but rather a paraphyletic set of neornithischian taxa. Thus, even as the known diversity of these taxa has dramatically increased over the past two decades, our knowledge of their placement relative to each other and the major ornithischian subclades remained incomplete. This study employs the largest phylogenetic dataset yet compiled to assess basal ornithischian relationships (255 characters for 65 species level terminal taxa). The resulting strict consensus tree is the most well-resolved, stratigraphically consistent hypothesis of basal ornithischian relationships yet hypothesized. The only non-iguanodontian ornithopod (=basal ornithopod) recovered in this analysis isHypsilophodon foxii. The majority of former ‘hypsilophodontid’ taxa are recovered within a single clade (Parksosauridae) that is situated as the sister-taxon to Cerapoda. The Parksosauridae is divided between two subclades, the Orodrominae and the Thescelosaurinae. This study does not recover a clade consisting of the Asian taxaChangchunsaurus,Haya, andJeholosaurus(=Jeholosauridae). Rather, the former two taxa are recovered as basal members of Thescelosaurinae, while the latter taxon is recovered in a clade withYueosaurusnear the base of Neornithischia.The endemic South American clade Elasmaria is recovered within the Thescelosaurinae as the sister taxon toThescelosaurus. This study supports the origination of Dinosauria and the early diversification of Ornithischia within Gondwana. Neornithischia first arose in Africa by the Early Jurassic before dispersing to Asia before the late Middle Jurassic, where much of the diversification among non-cerapodan neornithischians occurred. Under the simplest scenario the Parksosauridae originated in North America, with at least two later dispersals to Asia and one to South America. However, when ghost lineages are considered, an alternate dispersal hypothesis has thescelosaurines dispersing from Asia into South America (via North America) during the Early Cretaceous, then back into North America in the latest Cretaceous. The latter hypothesis may explain the dominance of orodromine taxa prior to the Maastrichtian in North America and the sudden appearance and wide distribution of thescelosaurines in North America beginning in the early Maastrichtian. While the diversity of parksosaurids has greatly increased over the last fifteen years, a ghost lineage of over 40 myr is present between the base of Parksosauridae and Cerapoda, indicating that much of the early history and diversity of this clade is yet to be discovered. This new phylogenetic hypothesis provides a comprehensive framework for testing further hypotheses regarding evolutionary patterns and processes within Ornithischia.

Updating the Bibliography of Interbreeding among Canis in North America

2020 ◽  
Vol 111 (3) ◽  
pp. 249-262 ◽  
Author(s):  
Bridgett M vonHoldt ◽  
Matthew L Aardema
Keyword(s):  
North America ◽  
Evolutionary History ◽  
Past Research ◽  
Early 20Th Century ◽  
The Past ◽  
Endangered Species Management ◽  
Species Management ◽  
History Of ◽  
And Behavior ◽  
Experimental Crosses

Abstract This bibliography provides a collection of references that documents the evolution of studies evidencing interbreeding among Canis species in North America. Over the past several decades, advances in biology and genomic technology greatly improved our ability to detect and characterize species interbreeding, which has significance for understanding species in a changing landscape as well as for endangered species management. This bibliography includes a discussion within each category of interbreeding, the timeline of developing evidence, and includes a review of past research conducted on experimental crosses. Research conducted in the early 20th century is rich with detailed records and photographs of hybrid offspring development and behavior. With the progression of molecular methods, studies can estimate historical demographic parameters and detect chromosomal patterns of ancestry. As these methods continue to increase in accessibility, the field will gain a deeper and richer understanding of the evolutionary history of North American Canis.

scholarly journals A new Palaeocene crocodylian from southern Argentina sheds light on the early history of caimanines

2018 ◽  
Vol 285 (1885) ◽  
pp. 20180843 ◽  
Author(s):  
Paula Bona ◽  
Martín D. Ezcurra ◽  
Francisco Barrios ◽  
María V. Fernandez Blanco
Keyword(s):  
North America ◽  
South America ◽  
Cladistic Analysis ◽  
South American ◽  
North Central ◽  
Skull Roof ◽  
History Of ◽  
Event Based ◽  
Dispersal Events ◽  
North And South America

Caimanines are crocodylians currently restricted to South and Central America and the oldest members are from lower Palaeocene localities of the Salamanca Formation (Chubut Province, Argentina). We report here a new caimanine from this same unit represented by a skull roof and partial braincase. Its phylogenetic relationships were explored in a cladistic analysis using standard characters and a morphogeometric two-dimensional configuration of the skull roof. The phylogenetic results were used for an event-based supermodel quantitative palaeobiogeographic analysis. The new species is recovered as the most basal member of the South American caimanines, and the Cretaceous North American lineage ‘ Brachychampsa and related forms' as the most basal Caimaninae. The biogeographic results estimated north-central North America as the ancestral area of Caimaninae, showing that the Cretaceous and Palaeocene species of the group were more widespread than thought and became regionally extinct in North America around the Cretaceous–Palaeocene boundary. A dispersal event from north-central North America during the middle Late Cretaceous explains the arrival of the group to South America. The Palaeogene assemblage of Patagonian crocodylians is composed of three lineages of caimanines as a consequence of independent dispersal events that occurred between North and South America and within South America around the Cretaceous–Palaeogene boundary.

The migration and evolution of floras in the southern hemisphere

Bothalia ◽  
1983 ◽  
Vol 14 (3/4) ◽  
pp. 325-328 ◽  
Author(s):  
P. H. Raven
Keyword(s):  
North America ◽  
South America ◽  
Southern Hemisphere ◽  
Relative Position ◽  
Southern South America ◽  
The Past ◽  
Main Pathway ◽  
Set Up ◽  
Warm Temperate ◽  
Northern And Southern Hemispheres

As modern groups of angiosperms have appeared over a period of more than 80 million years, the relative position of the southern continents has changed. For the First 20 m.y. of this period, opportunities for migration were good between Africa and Europe, and this constituted the main pathway for migration between the northern and southern hemispheres. South America progressively moved away from Africa and towards North America over the past 90 m.y. Southern South America and Australasia shared a rich, warm temperate rainforest flora until about 40 m.y. ago. The development of modern climates during the past 10 m.y. has set up modern patterns of vegetation.

Tensed evidentials: A typological study

2015 ◽  
Vol 19 (2) ◽  
Author(s):  
Eline Visser
Keyword(s):  
North America ◽  
South America ◽  
Information Source ◽  
Mental Activity ◽  
The Past ◽  
Grammatical Categories ◽  
America South ◽  
Insight Into

AbstractTo gain more insight into evidentiality, the grammatical marking of information source, it is worth studying the category in its relation to other grammatical categories. This study explores tensed evidentials, morphemes in which tense and evidentiality are fused, in 36 languages from four macro-areas (North America, South America, Eurasia, and Papunesia). The study reveals several interactions between tense values and evidential values. As opposed to what has been claimed, firsthand future evidentials seem to exist. Visual and non-visual evidentials occur equally with present and past, whereas mental activity evidentials and reportative evidentials are much more limited to the past. These findings conform to the logic of tense: every type of evidentiality can be gathered in the past, whereas some are less suited for present or future. As a result, we find exceptionless implicational hierarchies of the form

scholarly journals Fossil quality and naming dinosaurs

2008 ◽  
Vol 4 (6) ◽  
pp. 729-732 ◽  
Author(s):  
Michael J Benton
Keyword(s):  
New Species ◽  
North America ◽  
South America ◽  
Type Specimens ◽  
The Past ◽  
Relative Paucity ◽  
Good Material ◽  
Specimen Quality ◽  
The 1950S

The intense interest in dinosaurs through the past 30 years might have led to an increase in poor practice in naming new species. A review of the data shows that the reverse is the case. For 130 years, from the 1820s to the 1950s, most new species of dinosaurs were based on scrappy and incomplete material. After 1960, the majority of new species have been based on complete skulls or skeletons, and sometimes on materials from several individuals. This switch in the quality of type specimens corresponds to the recent explosive renaissance of interest in dinosaurs, during which the number of new species named per year has risen, from three or four in the 1950s, to thirty or more today. The pattern of specimen quality varies by continent, with the highest proportion of new species based on good material in North America, then Asia, then South America, then Africa and finally Europe. This ranking reflects a complex pattern of perhaps overstudy in Europe, immensely rich reserves of new dinosaur materials in North America and Asia, and a relative paucity in South America and Africa.

scholarly journals Origin of tropical American burrowing reptiles by transatlantic rafting

2007 ◽  
Vol 4 (1) ◽  
pp. 115-118 ◽  
Author(s):  
Nicolas Vidal ◽  
Anna Azvolinsky ◽  
Corinne Cruaud ◽  
S.Blair Hedges
Keyword(s):  
North America ◽  
Middle East ◽  
South America ◽  
Atlantic Ocean ◽  
Molecular Evidence ◽  
Terrestrial Vertebrates ◽  
Caribbean Islands ◽  
Squamate Reptiles ◽  
Land Mass ◽  
Dispersal Events

Populations of terrestrial or freshwater taxa that are separated by oceans can be explained by either oceanic dispersal or fragmentation of a previously contiguous land mass. Amphisbaenians, the worm lizards (approx. 165 species), are small squamate reptiles that are uniquely adapted to a burrowing lifestyle and inhabit Africa, South America, Caribbean Islands, North America, Europe and the Middle East. All but a few species are limbless and they rarely leave their subterranean burrows. Given their peculiar habits, the distribution of amphisbaenians has been assumed to be primarily the result of two land-mass fragmentation events: the split of the supercontinent Pangaea starting 200 Myr ago, separating species on the northern land mass (Laurasia) from those on the southern land mass (Gondwana), and the split of South America from Africa 100 Myr ago. Here we show with molecular evidence that oceanic dispersal—on floating islands—played a more prominent role, and that amphisbaenians crossed the Atlantic Ocean in the Eocene (40 Myr ago) resulting in a tropical American radiation representing one-half of all known amphisbaenian species. Until now, only four or five transatlantic dispersal events were known in terrestrial vertebrates. Significantly, this is the first such dispersal event to involve a group that burrows, an unexpected lifestyle for an oceanic disperser.

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