scholarly journals Recent and Rapid Radiation of the Highly Endangered Harlequin Frogs (Atelopus) into Central America Inferred from Mitochondrial DNA Sequences

Diversity ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 360
Author(s):  
Juan Ramírez ◽  
César Jaramillo ◽  
Erik Lindquist ◽  
Andrew Crawford ◽  
Roberto Ibáñez
Keyword(s):  
Mitochondrial Dna ◽  
South America ◽  
Central America ◽  
Dna Sequences ◽  
Central American ◽  
Tree Model ◽  
South American Species ◽  
Biogeographic History ◽  
Museum Samples ◽  
History Of

Populations of amphibians are experiencing severe declines worldwide. One group with the most catastrophic declines is the Neotropical genus Atelopus (Anura: Bufonidae). Many species of Atelopus have not been seen for decades and all eight Central American species are considered “Critically Endangered”, three of them very likely extinct. Nonetheless, the taxonomy, phylogeny, and biogeographic history of Central American Atelopus are still poorly known. In this study, the phylogenetic relationships among seven of the eight described species in Central America were inferred based on mitochondrial DNA sequences from 103 individuals, including decades-old museum samples and two likely extinct species, plus ten South American species. Among Central American samples, we discovered two candidate species that should be incorporated into conservation programs. Phylogenetic inference revealed a ladderized topology, placing species geographically furthest from South America more nested in the tree. Model-based ancestral area estimation supported either one or two colonization events from South America. Relaxed-clock analysis of divergence times indicated that Atelopus colonized Central America prior to 4 million years ago (Ma), supporting a slightly older than traditional date for the closure of the Isthmus. This study highlights the invaluable role of museum collections in documenting past biodiversity, and these results could guide future conservation efforts. An abstract in Spanish (Resumen) is available as supplementary material.

scholarly journals The role of Central American barriers in shaping the evolutionary history of the northernmost glassfrog,Hyalinobatrachium fleischmanni(Anura: Centrolenidae)

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6115 ◽  
Author(s):  
Angela M. Mendoza ◽  
Wilmar Bolívar-García ◽  
Ella Vázquez-Domínguez ◽  
Roberto Ibáñez ◽  
Gabriela Parra Olea
Keyword(s):  
Genetic Structure ◽  
Central America ◽  
Population Expansion ◽  
Central American ◽  
Fault System ◽  
Mountain Range ◽  
Amphibian Species ◽  
Biogeographic History ◽  
History Of ◽  
The Impact

The complex geological history of Central America has been useful for understanding the processes influencing the distribution and diversity of multiple groups of organisms. Anurans are an excellent choice for such studies because they typically exhibit site fidelity and reduced movement. The objective of this work was to identify the impact of recognized geographic barriers on the genetic structure, phylogeographic patterns and divergence times of a wide-ranging amphibian species,Hyalinobatrachium fleischmanni. We amplified three mitochondrial regions, two coding (COI and ND1) and one ribosomal (16S), in samples collected from the coasts of Veracruz and Guerrero in Mexico to the humid forests of Chocó in Ecuador. We examined the biogeographic history of the species through spatial clustering analyses (Geneland and sPCA), Bayesian and maximum likelihood reconstructions, and spatiotemporal diffusion analysis. Our data suggest a Central American origin ofH. fleischmanniand two posterior independent dispersals towards North and South American regions. The first clade comprises individuals from Colombia, Ecuador, Panama and the sister speciesHyalinobatrachium tatayoi; this clade shows little structure, despite the presence of the Andes mountain range and the long distances between sampling sites. The second clade consists of individuals from Costa Rica, Nicaragua, and eastern Honduras with no apparent structure. The third clade includes individuals from western Honduras, Guatemala, and Mexico and displays deep population structure. Herein, we synthesize the impact of known geographic areas that act as barriers to glassfrog dispersal and demonstrated their effect of differentiatingH. fleischmanniinto three markedly isolated clades. The observed genetic structure is associated with an initial dispersal event from Central America followed by vicariance that likely occurred during the Pliocene. The southern samples are characterized by a very recent population expansion, likely related to sea-level and climatic oscillations during the Pleistocene, whereas the structure of the northern clade has probably been driven by dispersal through the Isthmus of Tehuantepec and isolation by the Motagua–Polochic–Jocotán fault system and the Mexican highlands.

scholarly journals The Experience on Earthquake Risk in Central America

1977 ◽  
Vol 9 (3) ◽  
pp. 306-316
Keyword(s):  
South America ◽  
Central America ◽  
Seismic Activity ◽  
Volcanic Eruptions ◽  
Central American ◽  
Earthquake Risk ◽  
History Of ◽  
The Caribbean ◽  
North And South America ◽  
North And South

Presented by the Central American Actuarial Association (Asociacion Acturial Centroamericana) to the 13th ASTIN Colloquium.The Asociaciôn Actuarial Centroamericana (AAC) is a grouping of Actuaries from the Central American Republics of El Salvador, Guatemala, Honduras, Nicaragua, Costa Rica and Panama. The AAC is a contributing ASTIN member of the International Actuarial Association.Earthquakes have been a constant scourge of mankind. Central America has not escaped this phenomenon, indeed the territory has been most affected by them precisely because of its condition as an isthmus that serves as a fragile union between the continental land masses of North and South America, and in consequence being subject to disturbances by the displacement of the continental plates. Our lands abound with beautiful volcanoes, which have also contributed to local seismic activity. Whatever their origin, the earthquakes that have struck our country have left their share of destruction of lives and property.In Annex 1 a table is presented, showing a history of seismic activity and volcanic eruptions in the countries on the Caribbean Platform, in which we can appreciate in detail the catastrophes that occurred from the XVI Century until 1976.

scholarly journals Amazonia as the Origin and Diversification Area of Didelphidae (Mammalia: Metatheria), and a Review of the Fossil Record of the Clade

2021 ◽  
Author(s):  
Mariela C. Castro ◽  
Murilo J. Dahur ◽  
Gabriel S. Ferreira
Keyword(s):  
South America ◽  
Amazon Basin ◽  
Parametric Models ◽  
Isthmus Of Panama ◽  
Biogeographic History ◽  
Early Diversification ◽  
Northern Portion ◽  
History Of ◽  
Environmental Events ◽  
Fossil Records

AbstractDidelphidae is the largest New World radiation of marsupials, and is mostly represented by arboreal, small- to medium-sized taxa that inhabit tropical and/or subtropical forests. The group originated and remained isolated in South America for millions of years, until the formation of the Isthmus of Panama. In this study, we present the first reconstruction of the biogeographic history of Didelphidae including all major clades, based on parametric models and stratified analyses over time. We also compiled all the pre-Quaternary fossil records of the group, and contrasted these data to our biogeographic inferences, as well as to major environmental events that occurred in the South American Cenozoic. Our results indicate the relevance of Amazonia in the early diversification of Didelphidae, including the divergence of the major clades traditionally ranked as subfamilies and tribes. Cladogeneses in other areas started in the late Miocene, an interval of intense shifts, especially in the northern portion of Andes and Amazon Basin. Occupation of other areas continued through the Pliocene, but few were only colonized in Quaternary times. The comparison between the biogeographic inference and the fossil records highlights some further steps towards better understanding the spatiotemporal evolution of the clade. Finally, our results stress that the early history of didelphids is obscured by the lack of Paleogene fossils, which are still to be unearthed from low-latitude deposits of South America.

Hoplonannus australis sp. nov. (Hemiptera, Schizopteridae): amended diagnosis of the genus and first record from South America

Zootaxa ◽  
2019 ◽  
Vol 4568 (2) ◽  
pp. 394
Author(s):  
DIEGO DUTRA SILVEIRA ◽  
ALINE BARCELLOS ◽  
ALEXANDER KNYSHOV
Keyword(s):  
New Species ◽  
South America ◽  
Central America ◽  
First Record ◽  
South American ◽  
South American Species ◽  
The Right ◽  
New Diagnosis

Hoplonannus McAtee & Maloch, 1925 comprises three species described from Central America. Females of all these species are known only from brachypterous specimens. This paper describes the first South American species of the genus, Hoplonannus australis sp. nov. The new species differs from its congeners, in females, by the submacroptery, presence of ocelli and a basal bulge in the seventh sternite; in males, it differs by the presence of a process in the eighth tergite and the right paramere bifurcate apically, with branches subparallel. These traits entail a new diagnosis for the genus. 

scholarly journals Archaeological Central American maize genomes suggest ancient gene flow from South America

2020 ◽  
Vol 117 (52) ◽  
pp. 33124-33129
Author(s):  
Logan Kistler ◽  
Heather B. Thakar ◽  
Amber M. VanDerwarker ◽  
Alejandra Domic ◽  
Anders Bergström ◽  
...  
Keyword(s):  
Gene Flow ◽  
South America ◽  
Central America ◽  
Central American ◽  
Morphological Data ◽  
Radiocarbon Dates ◽  
Rock Shelter ◽  
Maize Varieties ◽  
American Maize ◽  
Modern Maize

Maize (Zea mays ssp. mays) domestication began in southwestern Mexico ∼9,000 calendar years before present (cal. BP) and humans dispersed this important grain to South America by at least 7,000 cal. BP as a partial domesticate. South America served as a secondary improvement center where the domestication syndrome became fixed and new lineages emerged in parallel with similar processes in Mesoamerica. Later, Indigenous cultivators carried a second major wave of maize southward from Mesoamerica, but it has been unclear until now whether the deeply divergent maize lineages underwent any subsequent gene flow between these regions. Here we report ancient maize genomes (2,300–1,900 cal. BP) from El Gigante rock shelter, Honduras, that are closely related to ancient and modern maize from South America. Our findings suggest that the second wave of maize brought into South America hybridized with long-established landraces from the first wave, and that some of the resulting newly admixed lineages were then reintroduced to Central America. Direct radiocarbon dates and cob morphological data from the rock shelter suggest that more productive maize varieties developed between 4,300 and 2,500 cal. BP. We hypothesize that the influx of maize from South America into Central America may have been an important source of genetic diversity as maize was becoming a staple grain in Central and Mesoamerica.

Central America-US Relations

2019 ◽  
Author(s):  
Evan D. McCormick
Keyword(s):  
United States ◽  
Central America ◽  
The United States ◽  
Central American ◽  
Main Element ◽  
Democratic Capitalism ◽  
Liberal Democratic ◽  
Foreign Policies ◽  
History Of ◽  
The Cold War

Since gaining independence in 1823, the states comprising Central America have had a front seat to the rise of the United States as a global superpower. Indeed, more so than anywhere else, the United States has sought to use its power to shape Central America into a system that heeds US interests and abides by principles of liberal democratic capitalism. Relations have been characterized by US power wielded freely by officials and non-state actors alike to override the aspirations of Central American actors in favor of US political and economic objectives: from the days of US filibusterers invading Nicaragua in search of territory; to the occupations of the Dollar Diplomacy era, designed to maintain financial and economic stability; to the covert interventions of the Cold War era. For their part, the Central American states have, at various times, sought to challenge the brunt of US hegemony, most effectively when coordinating their foreign policies to balance against US power. These efforts—even when not rejected by the United States—have generally been short-lived, hampered by economic dependency and political rivalries. The result is a history of US-Central American relations that wavers between confrontation and cooperation, but is remarkable for the consistency of its main element: US dominance.

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