Lions and brown bears colonised North America in multiple synchronous waves of dispersal across the Bering Land Bridge

2021 ◽  
Author(s):  
Alexander T Salis ◽  
Sarah C E Bray ◽  
Michael S Y Lee ◽  
Holly Heiniger ◽  
Ross Barnett ◽  
...  
Keyword(s):  
North America ◽  
Land Bridge ◽  
Brown Bears ◽  
Bering Land Bridge

scholarly journals Lions and brown bears colonized North America in multiple synchronous waves of dispersal across the Bering Land Bridge

2020 ◽  
Author(s):  
Alexander T Salis ◽  
Sarah C E Bray ◽  
Michael S Y Lee ◽  
Holly Heiniger ◽  
Ross Barnett ◽  
...  
Keyword(s):  
Population Dynamics ◽  
North America ◽  
Glacial Cycles ◽  
Land Bridge ◽  
Large Herbivores ◽  
Brown Bears ◽  
Sea Levels ◽  
North West ◽  
North East ◽  
Bering Land Bridge

AbstractThe Bering Land Bridge connecting North America and Eurasia was periodically exposed and inundated by oscillating sea levels during the Pleistocene glacial cycles. This land connection allowed the intermittent dispersal of animals, including humans, between Western Beringia (far north-east Asia) and Eastern Beringia (north-west North America), changing the faunal community composition of both continents. The Pleistocene glacial cycles also had profound impacts on temperature, precipitation, and vegetation, impacting faunal community structure and demography. While these paleoenvironmental impacts have been studied in many large herbivores from Beringia (e.g., bison, mammoths, horses), the Pleistocene population dynamics of the diverse guild of carnivorans present in the region are less well understood, due to their lower abundances. In this study, we analyze mitochondrial genome data from ancient brown bears (Ursus arctos; n = 103) and lions (Panthera spp.; n = 39), two megafaunal carnivorans that dispersed into North America during the Pleistocene. Our results reveal striking synchronicity in the population dynamics of Beringian lions and brown bears, with multiple waves of dispersal across the Bering Land Bridge coinciding with glacial periods of low sea levels, as well as synchronous local extinctions in Eastern Beringia during Marine Isotope Stage 3. The evolutionary histories of these two taxa underscore the crucial biogeographic role of the Bering Land Bridge in the distribution, turnover, and maintenance of megafaunal populations in North America.

Flake Tools in the American Arctic: Some Speculations

1964 ◽  
Vol 29 (3) ◽  
pp. 338-344 ◽  
Author(s):  
Edwin N. Wilmsen
Keyword(s):  
North America ◽  
Central Asia ◽  
New World ◽  
Yukon Territory ◽  
River Delta ◽  
The Arctic ◽  
Land Bridge ◽  
Bering Land Bridge

AbstractTwo sites, Kogruk (at the summit of Anaktuvuk Pass, Alaska) and Engigstciak (at the head of the Firth River delta, Yukon Territory, Canada), have recently yielded flake-tool assemblages which show striking resemblances to a Eurasiatic flake-blade tradition based on a Levallois-Mousterian stone-chipping technique, and to the Clovis flake-blade tradition of America which appears to be based on a similar chipping technique. It is suggested that these traditions are historically related and that the Arctic sites provide a possible link between the two. The presence of incipient fluting in Siberia and at Engigstciak may prove significant. Dating is discussed in terms of the ecology and geology of the sites and is correlated with the probable periods of availability of the Bering land bridge. An upland-foothills zone is seen to be essentially continuous from central Asia to central North America. It is suggested that this zone provided the only environmentally compatible link between the two continents, and that it was therefore the most probable route of early hunting peoples into the New World.

THE IDENTIFICATION AND ORIGIN OF THE STRAINS OF THE LARCH SAWFLY, PRISTIPHORA ERICHSONII (HYMENOPTERA: TENTHREDINIDAE), IN NORTH AMERICA

1974 ◽  
Vol 106 (11) ◽  
pp. 1121-1131 ◽  
Author(s):  
Horne R. Wong
Keyword(s):  
North America ◽  
North American ◽  
Land Bridge ◽  
Bering Land Bridge ◽  
Pristiphora Erichsonii ◽  
Larch Sawfly

AbstractThis study identifies and presents a key to five strains of the larch sawfly, Pristiphora erichsonii (Hartig), which are designated Aweme, Fernie, Ambleside, Thirlmire, and Salzburg.Aweme and Fernie strains occur only in North America and Salzburg strain is confined to Eurasia. Two Eurasian strains, Ambleside and Thirlmire, were accidentally introduced into Canada from England by 1913 among cocoons shipped for the release of the parasite Mesoleius tenthredinis Morley. It is postulated that the ancestors of Aweme-Salzburg strains Fernie–Thirlmire strains dispersed across the Bering Land Bridge into North America some time in the Miocene. These phyletic lines evolved into distinct Eurasian and North American strains. Early infestations in North America apparently consisted of North American strains, while later outbreaks have consisted primarily of the recently introduced Eurasian strains.

scholarly journals Setting the Stage: The Late Pleistocene Colonization of North America

Quaternary ◽  
2018 ◽  
Vol 2 (1) ◽  
pp. 1 ◽  
Author(s):  
Michael O’Brien
Keyword(s):  
North America ◽  
Late Pleistocene ◽  
New World ◽  
Pacific Coast ◽  
Ice Sheets ◽  
Land Bridge ◽  
Projectile Points ◽  
Bering Land Bridge ◽  
The Pacific ◽  
Northern Half

The timing of human entrance into North America has been a topic of debate that dates back to the late 19th century. Central to the modern discussion is not whether late Pleistocene-age populations were present on the continent, but the timing of their arrival. Key to the debate is the age of tools—bone rods, large prismatic stone blades, and bifacially chipped and fluted stone weapon tips—often found associated with the remains of late Pleistocene fauna. For decades, it was assumed that this techno-complex—termed “Clovis”—was left by the first humans in North America, who, by 11,000–12,000 years ago, made their way eastward across the Bering Land Bridge, or Beringia, and then turned south through a corridor that ran between the Cordilleran and Laurentide ice sheets, which blanketed the northern half of the continent. That scenario has been challenged by more-recent archaeological and archaeogenetic data that suggest populations entered North America as much as 15,300–14,300 years ago and moved south along the Pacific Coast and/or through the ice-free corridor, which apparently was open several thousand years earlier than initially thought. Evidence indicates that Clovis might date as early as 13,400 years ago, which means that it was not the first technology in North America. Given the lack of fluted projectile points in the Old World, it appears certain that the Clovis techno-complex, or at least major components of it, emerged in the New World.

The enigmatic history of the European, Asian and American plethodontid salamanders

2013 ◽  
Vol 34 (3) ◽  
pp. 323-336 ◽  
Author(s):  
David B. Wake
Keyword(s):  
North America ◽  
Close Relative ◽  
Land Bridge ◽  
Time Estimates ◽  
Bering Land Bridge ◽  
Plethodontid Salamanders ◽  
New Information ◽  
History Of ◽  
Published Research ◽  
American Clade

Recently published research addressing the question of relationships and biogeography of European plethodontid salamanders has refined time estimates for divergence from American relatives. The recently discovered Korean plethodontid Karsenia is either the sister-taxon of Hydromantes (which has members in Europe and California), or a close relative and co-member of a larger clade that originated in western North America, not eastern North America as formerly thought. The new information strengthens the biogeographical hypothesis that Hydromantes entered Eurasia via the Bering Land Bridge. Arguments are made favoring the placement of European and American relatives in a genus Hydromantes, with an American clade (subgenus Hydromantes) and a European clade (subgenera Atylodes and Speleomantes).

scholarly journals Assembly of the eastern North American herpetofauna: new evidence from lizards and frogs

2006 ◽  
Vol 2 (3) ◽  
pp. 388-392 ◽  
Author(s):  
J Robert Macey ◽  
James A Schulte ◽  
Jared L Strasburg ◽  
Jennifer A Brisson ◽  
Allan Larson ◽  
...  
Keyword(s):  
North America ◽  
North American ◽  
Eastern North America ◽  
Land Bridge ◽  
Dna Evidence ◽  
Bering Land Bridge ◽  
Biotic Diversity ◽  
Almost All ◽  
Dispersal Events ◽  
New Evidence

Darwin first recognized the importance of episodic intercontinental dispersal in the establishment of worldwide biotic diversity. Faunal exchange across the Bering Land Bridge is a major example of such dispersal. Here, we demonstrate with mitochondrial DNA evidence that three independent dispersal events from Asia to North America are the source for almost all lizard taxa found in continental eastern North America. Two other dispersal events across Beringia account for observed diversity among North American ranid frogs, one of the most species-rich groups of frogs in eastern North America. The contribution of faunal elements from Asia via dispersal across Beringia is a dominant theme in the historical assembly of the eastern North American herpetofauna.

A review of the ectoparasitic Leptinus beetles of North America (Coleoptera: Leptinidae)

1982 ◽  
Vol 60 (7) ◽  
pp. 1517-1527 ◽  
Author(s):  
Stewart B. Peck
Keyword(s):  
United States ◽  
North America ◽  
Mississippi River ◽  
Western North America ◽  
Land Bridge ◽  
Blarina Brevicauda ◽  
Bering Land Bridge ◽  
Early Tertiary ◽  
The Family ◽  
Central United States

Leptinus beetles are facultative ectoparasites known to occur on 18 species of small mammals in North America. Leptinus americanus is restricted to the central United States, west of the Mississippi River. Its hosts and seasonality are unknown. Leptinus orientamericanus n.sp. is widespread east of the Mississippi River. It occurs on seven hosts, most frequently on Blarina brevicauda and Scalopus aquaticus and during fall and winter months. Leptinus occidentamericanus n.sp. has a range in western North America from California to Alaska and the Yukon. It occurs on 11 hosts, most frequently on Sorex trowbridgii, and during spring and fall months. A hypothesis of evolution is given for all nine species in the genus. It suggests a Palaearctic origin for the family and genus and an early Tertiary entry to North America by a Bering land bridge.

Bilyjomyia, a new genus of the tribe Macropelopiini from the Holarctic (Diptera: Chironomidae)

Zootaxa ◽  
2009 ◽  
Vol 2166 (1) ◽  
pp. 57-68 ◽  
Author(s):  
HIROMI NIITSUMA ◽  
CHARLES N. WATSON JR.
Keyword(s):  
North America ◽  
Adult Male ◽  
New Genus ◽  
Generic Diagnosis ◽  
Immature Stages ◽  
Life Stages ◽  
Western North America ◽  
Posterior Edge ◽  
Land Bridge ◽  
Bering Land Bridge

The genus Bilyjomyia is erected for Apsectrotanypus algens (Coquillett, 1902) from western North America and B. fontana n. sp. from Japan. A generic diagnosis and a description are given for all life stages. Bilyjomyia algens is redescribed. All life stages of Bilyjomyia fontana are described and figured. The new genus shows affinities to Macropelopia Thienemann and Bethbilbeckia Fittkau et Murray in the immature stages. Bilyjomyia can be distinguished from all other known Macropelopiini by the following features: the reduced setation of T.IX and the restriction of these setae to the tergal posterior edge in the adult male; the aeropyles of the thoracic horn in the pupa; the labral sclerite and the position and form of the ventral cephalic setae in the larva. The distribution of Bilyjomyia indicates dispersal across the Bering Land Bridge, a pattern known in some other genera of Chironomidae and other orders of insects.

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