scholarly journals Early human dispersals within the Americas

Science ◽  
2018 ◽  
Vol 362 (6419) ◽  
pp. eaav2621 ◽  
Author(s):  
J. Víctor Moreno-Mayar ◽  
Lasse Vinner ◽  
Peter de Barros Damgaard ◽  
Constanza de la Fuente ◽  
Jeffrey Chan ◽  
...  

Studies of the peopling of the Americas have focused on the timing and number of initial migrations. Less attention has been paid to the subsequent spread of people within the Americas. We sequenced 15 ancient human genomes spanning from Alaska to Patagonia; six are ≥10,000 years old (up to ~18× coverage). All are most closely related to Native Americans, including those from an Ancient Beringian individual and two morphologically distinct “Paleoamericans.” We found evidence of rapid dispersal and early diversification that included previously unknown groups as people moved south. This resulted in multiple independent, geographically uneven migrations, including one that provides clues of a Late Pleistocene Australasian genetic signal, as well as a later Mesoamerican-related expansion. These led to complex and dynamic population histories from North to South America.

Author(s):  
Mariela C. Castro ◽  
Murilo J. Dahur ◽  
Gabriel S. Ferreira

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.


Science ◽  
2015 ◽  
Vol 347 (6224) ◽  
pp. 835-835 ◽  
Author(s):  
B. M. Kemp ◽  
J. Lindo ◽  
D. A. Bolnick ◽  
R. S. Malhi ◽  
J. C. Chatters

PLoS ONE ◽  
2018 ◽  
Vol 13 (11) ◽  
pp. e0208062 ◽  
Author(s):  
César Méndez ◽  
Amalia Nuevo Delaunay ◽  
Roxana Seguel ◽  
Antonio Maldonado ◽  
Ismael Murillo ◽  
...  

2009 ◽  
Vol 197 (1-2) ◽  
pp. 27-34 ◽  
Author(s):  
Pavel M. Dolukhanov ◽  
Sergei V. Kadurin ◽  
Evgeny P. Larchenkov

2016 ◽  
Vol 88 (2) ◽  
pp. 829-845 ◽  
Author(s):  
THAIS M.F. FERREIRA ◽  
ADRIANA ITATI OLIVARES ◽  
LEONARDO KERBER ◽  
RODRIGO P. DUTRA ◽  
LEONARDO S. AVILLA

ABSTRACT Echimyidae (spiny rats, tree rats and the coypu) is the most diverse family of extant South American hystricognath rodents (caviomorphs). Today, they live in tropical forests (Amazonian, coastal and Andean forests), occasionally in more open xeric habitats in the Cerrado and Caatinga of northern South America, and open areas across the southern portion of the continent (Myocastor). The Quaternary fossil record of this family remains poorly studied. Here, we describe the fossil echimyids found in karst deposits from southern Tocantins, northern Brazil. The analyzed specimens are assigned to Thrichomys sp., Makalata cf. didelphoides and Proechimys sp. This is the first time that a fossil of Makalata is reported. The Pleistocene record of echimyids from this area is represented by fragmentary remains, which hinders their determination at specific levels. The data reported here contributes to the understanding of the ancient diversity of rodents of this region, evidenced until now in other groups, such as the artiodactyls, cingulates, carnivores, marsupials, and squamate reptiles.


2004 ◽  
Vol 62 (1) ◽  
pp. 105-109 ◽  
Author(s):  
Carolyn L. Ramsey ◽  
Paul A. Griffiths ◽  
Daryl W. Fedje ◽  
Rebecca J. Wigen ◽  
Quentin Mackie

Recent investigations of a limestone solution cave on the Queen Charlotte Islands (Haida Gwaii) have yielded skeletal remains of fauna including late Pleistocene and early Holocene bears, one specimen of which dates to ca. 14,400 14C yr B.P. This new fossil evidence sheds light on early postglacial environmental conditions in this archipelago, with implications for the timing of early human migration into the Americas.


Author(s):  
João Carlos Moreno De Sousa

Brazilian archaeological literature has insisted for decades upon associating hunter-gatherer sites dated to the Pleistocene–Holocene transition either to the Itaparica tradition, if located in central or northeastern Brazil, or to the Umbu tradition and Humaitá tradition, if located in southern Brazil, Uruguay, or any other adjacent part of Paraguay and Argentina. These associations have been based almost entirely on the presence or absence of lesmas and “projectile points,” regardless of their morphological and technological features. In the Uruguayan archaeological literature, three other cultures are recognised: Fell industry, Catalanense industry, and Tigre tradition, all in the Uruguayan region. However, the last 10 years of systematic studies on the lithic assemblages from these sites have shown that Paleoindian societies from Eastern South America are more culturally diverse than expected and that previously defined archaeological cultures present several issues in their definition, suggesting that many of these “traditions” are not valid and should no longer be used. Instead, new lithic industries and archaeological cultures should be defined only when cultural patterns are observable through systematic analyses.


2021 ◽  
Author(s):  
Kelli S Ramos ◽  
Aline C Martins ◽  
Gabriel A R Melo

Bees are presumed to have arisen in the early to mid-Cretaceous coincident with the fragmentation of the southern continents and concurrently with the early diversification of the flowering plants. Among the main groups of bees, Andreninae sensu lato comprise about 3000 species widely distributed with greatest and disjunct diversity in arid areas of North America, South America, and the Palearctic region. Here, we present the first comprehensive dated phylogeny and historical biogeographic analysis for andrenine bees, including representatives of all currently recognized tribes. Our analyses rely on a dataset of 106 taxa and 7952 aligned nucleotide positions from one mitochondrial and six nuclear loci. Andreninae is strongly supported as a monophyletic group and the recovered phylogeny corroborates the commonly recognized clades for the group. Thus, we propose a revised tribal classification that is congruent with our phylogenetic results. The time-calibrated phylogeny and ancestral range reconstructions of Andreninae reveal a fascinating evolutionary history with Gondwana patterns that are unlike those observed in other subfamilies of bees. Andreninae arose in South America during the Late Cretaceous around 90 Million years ago (Ma) and the origin of tribes occurred through a relatively long time-window from this age to the Miocene. The early evolution of the main lineages took place in South America until the beginning of Paleocene with North American fauna origin from it and Palearctic from North America as results of multiple lineage interchanges between these areas by long-distance dispersal or hopping through landmass chains. Overall, our analyses provide strong evidence of amphitropical distributional pattern currently observed in Andreninae in the American continent as result at least three periods of possible land connections between the two American landmasses, much prior to the Panama Isthmus closure. The andrenine lineages reached the Palearctic region through four dispersal events from North America during the Eocene, late Oligocene and early Miocene, most probably via the Thulean Bridge. The few lineages with Afrotropical distribution likely originated from a Palearctic ancestral in the Miocene around 10 Ma when these regions were contiguous, and the Sahara Desert was mostly vegetated making feasible the passage by several organisms. Incursions of andrenine bees to North America and then onto the Old World are chronological congruent with distinct periods when open-vegetation habitats were available for trans-continental dispersal and at the times when aridification and temperature decline offered favorable circumstances for bee diversification.


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