scholarly journals Bison phylogeography constrains dispersal and viability of the Ice Free Corridor in western Canada

2016 ◽  
Vol 113 (29) ◽  
pp. 8057-8063 ◽  
Author(s):  
Peter D. Heintzman ◽  
Duane Froese ◽  
John W. Ives ◽  
André E. R. Soares ◽  
Grant D. Zazula ◽  
...  
Keyword(s):  
North America ◽  
Western Canada ◽  
Limited Data ◽  
Radiocarbon Dates ◽  
The North ◽  
Human Dispersal ◽  
Continued Use ◽  
Dispersal Routes ◽  
North And South ◽  
Over Time

The Ice Free Corridor has been invoked as a route for Pleistocene human and animal dispersals between eastern Beringia and more southerly areas of North America. Despite the significance of the corridor, there are limited data for when and how this corridor was used. Hypothetical uses of the corridor include: the first expansion of humans from Beringia into the Americas, northward postglacial expansions of fluted point technologies into Beringia, and continued use of the corridor as a contact route between the north and south. Here, we use radiocarbon dates and ancient mitochondrial DNA from late Pleistocene bison fossils to determine the chronology for when the corridor was open and viable for biotic dispersals. The corridor was closed after ∼23,000 until 13,400 calendar years ago (cal y BP), after which we find the first evidence, to our knowledge, that bison used this route to disperse from the south, and by 13,000 y from the north. Our chronology supports a habitable and traversable corridor by at least 13,000 cal y BP, just before the first appearance of Clovis technology in interior North America, and indicates that the corridor would not have been available for significantly earlier southward human dispersal. Following the opening of the corridor, multiple dispersals of human groups between Beringia and interior North America may have continued throughout the latest Pleistocene and early Holocene. Our results highlight the utility of phylogeographic analyses to test hypotheses about paleoecological history and the viability of dispersal routes over time.

Postbellum America

2000 ◽  
Author(s):  
William B. Meyer
Keyword(s):  
Internal Migration ◽  
The Other ◽  
National Unity ◽  
Climatic Zones ◽  
The North ◽  
Human Trait ◽  
The One ◽  
North And South ◽  
The U.S ◽  
Over Time

One of the earliest historians of the Civil War saw it as a fundamental clash between the peoples of different latitudes. Climate had made the antebellum North and South distinct societies and natural enemies, John W. Draper argued, the one democratic and individualist, the other aristocratic and oligarchical. If such were the case, the future of the reunited states was hardly a bright one. But Draper saw no natural barriers to national unity that wise policy could not surmount. The restlessness and transience of American life that many deplored instead merited, in his view, every assistance possible. In particular, he wrote, Americans needed to be encouraged to move as freely across climatic zones as they already did within them. The tendency of North and South to congeal into hostile types of civilization could be frustrated, but only by an incessant mingling of people. Sectional discord was inevitable only if the natural law that "emigrants move on parallels of latitude" were left free to take its course. These patterns of emigration were left free, for the most part, but without the renewed strife that Draper feared. After the war as before it, few settlers relocating to new homes moved far to the north or south of their points of origin. As late as 1895, Henry Gannett, chief geographer to the U.S. Census, could still describe internal migration as "mainly conducted westward along parallels of latitude." More often as time went on, it was supposed that race and not merely habit underlay the pattern, that climatic preferences were innate, different stocks of people staying in the latitudes of their forbears by the compulsion of biology. Thus, it was supposed, Anglo-Saxons preferred cooler lands than Americans of Mediterranean ancestry, while those of African descent preferred warmer climates than either. Over time, though, latitude loosened its grip and exceptions to the rule multiplied. As the share of the population in farming declined, so did the strongest reason for migrants to stay within familiar climates. Even by the time Gannett wrote, the tendency that he described, though still apparent, was weaker than it had been at mid-century. It weakened because a preference for familiar climates was not a fixed human trait but one shaped by experience and wants, and capable of changing as these variables changed.

scholarly journals Migration of exotic species of ammonites during highstands of sea level

1992 ◽  
Vol 6 ◽  
pp. 324-324
Author(s):  
Keith Young
Keyword(s):  
North America ◽  
South America ◽  
Exotic Species ◽  
Sea Level ◽  
South Atlantic ◽  
Horn Of Africa ◽  
Mozambique Channel ◽  
The North ◽  
North And South ◽  
Early Late

In northeastern Chihuahua and Trans-Pecos Texas, in the early Late Albian zone of Hysteroceras varicosum occurs the Boeseites romeri (Haas) fauna with B. romeri (Hass), B. perarmata (Hass), B. aff. barbouri (Haas), B. cf. howelli (Haas), B.proteus (Haas), Prohysteroceras cf. P. hanhaense Haas, Elobiceras sp., and Dipoloceras (?) sp. B. perarmata has also been collected at Cerro Mercado, near Monclova, Coahuila. Haas originally described this fauna from Angola. Now, from rocks in the same zone in the Sierra Mojada, Coahuila, Mexico, there is a form related to if not identical with Hysteroceras famelicum Van Hoepen, also originally described from Angola and also from the zone of Hysteroceras varicosum.These fossils are known only from southern North America and Angola; they have not been described from the European Tethys. In 1984 I suggested that during the highstand of sea level of the early Late Albian (Hysteroceras varicosum zone) these ammonites migrated from Angola to Mexico and Trans-Pecos Texas via an epeiric seaway extending across the sag between South America and Africa proposed by Kennedy and Cooper. This would be twelve to fifteen million years prior to an oceanic connection between the North and South Atlantic.I would now ask, can similar epeiric seas and highstands of sea level explain the migration of successive European, Tethyan, Jurassic ammonite faunas down the Mozambique Channel and around the horn of Africa into the Neuquen Basin of Argentina before Africa and Antarctica separated, as proposed by Spath.

Invasion of the New Zealand Coastline by European Sea-Rocket (Cakile maritima) and American Sea-Rocket (Cakile edentula)

2011 ◽  
Vol 4 (2) ◽  
pp. 260-263 ◽  
Author(s):  
Roger D. Cousens ◽  
Jane M. Cousens
Keyword(s):  
New Zealand ◽  
North America ◽  
West Coast ◽  
Congeneric Species ◽  
The West ◽  
The Past ◽  
The North ◽  
Cakile Maritima ◽  
Cakile Edentula ◽  
North And South

AbstractOn the west coast of North America and in Australia, there have been parallel cases of sequential invasion and replacement of the shoreline plant American sea-rocket by European sea-rocket. A similar pattern has also occurred in New Zealand. For 30 to 40 yr, from its first recording in 1921, American sea-rocket spread throughout the eastern coastlines of the North and South Islands of New Zealand. European sea-rocket has so far been collected only on the North Island. From its first collection in 1937, European sea-rocket spread to the northern extremity of the island by 1973, and by 2010, it had reached the southernmost limit. In the region where both species have occurred in the past, American sea-rocket is now rarely found. This appears to be another example of congeneric species displacement.

DOES THE GLOBAL NORTH STILL DOMINATE WOMEN'S INTERNATIONAL ORGANIZING? A NETWORK ANALYSIS FROM 1978 TO 2008*

2018 ◽  
Vol 23 (1) ◽  
pp. 1-21 ◽  
Author(s):  
Melanie M. Hughes ◽  
Pamela Paxton ◽  
Sharon Quinsaat ◽  
Nicholas Reith
Keyword(s):  
Global South ◽  
Women's Movements ◽  
International Nongovernmental Organizations ◽  
Organizational Membership ◽  
The North ◽  
Exchange Information ◽  
Global North ◽  
National Boundaries ◽  
North And South ◽  
Over Time

Over the last century, women increasingly transcended national boundaries to exchange information, build solidarity, and bring change. Accounts suggest that as women's international presence expanded, the types of women who participated also shifted. During the first wave of women's movements, White Western women dominated, but over time women of the Global South increasingly organized themselves. Yet we do not know whether North-South inequalities in women's organizational membership have diminished. We collect longitudinal network data on 447 women's international nongovernmental organizations (WINGOs) and use visual tools and network measures to explore changes in the network structure from 1978 to 2008. Results suggest (1) WINGOs—while increasing in frequency—are not connecting to greater numbers of countries, (2) the North/South split in WINGO memberships does not change over time, (3) significant power differences between the North and South persist, and (4) substantial inequalities in WINGO memberships within the Global South also exist.

Archaeological Corn from Pueblo Bonito, Chaco Canyon, New Mexico: Dates, Contexts, Sources

2008 ◽  
Vol 73 (3) ◽  
pp. 491-511 ◽  
Author(s):  
Linda S. Cordell ◽  
H. Wolcott Toll ◽  
Mollie S. Toll ◽  
Thomas C. Windes
Keyword(s):  
Zea Mays ◽  
New Mexico ◽  
Chaco Canyon ◽  
Historic Period ◽  
Change Over Time ◽  
Radiocarbon Dates ◽  
San Juan Basin ◽  
Geochemical Study ◽  
Continued Use ◽  
Over Time

We report measurements made on eight corncobs (Zea mays) excavated in the 1890s from Pueblo Bonito, Chaco Canyon, New Mexico. Seven of these corncobs were analyzed previously in a geochemical study aimed at determining the locations of the fields in which they were grown. We report radiocarbon dates obtained on these seven corncobs. Comparing the morphologies of the eight corncobs with other archaeological samples of corn from the San Juan Basin supports observations that Pueblo Bonito cobs are larger and have more kernel rows than some other basin samples. The radiocarbon dates preclude the possibility that these seven corncobs represent modern or historic period maize. The dates presented do not support a previous interpretation that there was a change over time in the locations where this corn may have been grown. Not ruling out other possibilities, the dates obtained, the special characteristics of this corn, and its presence in older rooms in Pueblo Bonito argue for continued use of Pueblo Bonito for special purposes over many centuries. In Pueblo belief, as among many indigenous agricultural cultures of the Americas, corn is an important source of sacred power.

Stratospheric cirrus clouds related to deep convection over North America observed by satellite measurements

2021 ◽  
Author(s):  
Ling Zou ◽  
Lars Hoffmann ◽  
Sabine Griessbach ◽  
Lunche Wang
Keyword(s):  
North America ◽  
Formation Mechanism ◽  
Great Plains ◽  
Gravity Waves ◽  
North Atlantic ◽  
Deep Convection ◽  
Eastern Pacific ◽  
Western Canada ◽  
The North ◽  
North Eastern

<p>Cirrus clouds in the stratosphere (SCCs) regulate the water vapor budget in the stratosphere, impact the stratosphere and tropopshere exchange, and affect the surface energy balance. But the knowledge of its occurrence and formation mechanism is limited, especially in middle and high latitudes. In this study, we aim to assess the occurrence frequencies of SCC over North America based on The Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) instrument during the years 2006 to 2018. Possible driving forces such as deep convection are assessed based on Atmospheric Infrared Sounder (AIRS) observations during the same time. </p><p>Results show that at nighttime, SCCs are most frequently observed during the thunderstorm season over the Great Plains from May to August (MJJA) with maximum occurrence frequency of 6.2%. During the months from November to February (NDJF), the highest SCCs occurrence frequencies are 5.5% over the North-Eastern Pacific, western Canada and 4.4% over the western North Atlantic. Occurrence frequencies of deep convection and strong storm systems from AIRS show similar hotspots like the SCCs, with highest occurrence frequencies being observed over the Great Plains in MJJA (4.4%) and over the North-Eastern Pacific, western Canada and the western North Atlantic in NDJF (~2.5%). Both, seasonal patterns and daily time series of SCCs and deep convection show a high degree of spatial and temporal correlation. As further analysis indicates that the maximum fraction of SCCs generated by deep convection is 74% over the Great Plains in MJJA and about 50% over the western North Atlantic, the North-Eastern Pacific and western Canada in NDJF, we conclude that, locally and regionally, deep convection is a leading factor for the formation of SCCs over North America. Other studies stressed the relevance of isentropic transport, double tropopause events, or gravity waves for the formation of SCCs. </p><p>In this study, we also analyzed the impact of gravity waves as a secondary formation mechanism for SCCs, as the Great Plains is a well-known hotspot for stratospheric gravity waves. In case of SCCs that are not directly linked to deep convection, we found that stratospheric gravity wave observations correlate in as much as 30% of the cases over the Great Plains in MJJA, about 50% over the North-Eastern Pacific, western Canada and maximally 90% over eastern Canada and the north-west Atlantic in NDJF. </p><p>Our results provide better understanding of the physical processes and climate variability related to SCCs and will be of interest for modelers as SCC sources such as deep convection and gravity waves are small-scale processes that are difficult to represent in global general circulation models. </p>

Making Harmful Traditional Practices

2016 ◽  
Author(s):  
Saida Hodžić
Keyword(s):  
Northern Ghana ◽  
Traditional Practices ◽  
Traditional Practice ◽  
The Public ◽  
Primary Mode ◽  
The North ◽  
A Site ◽  
Harmful Traditional Practices ◽  
North And South ◽  
Over Time

Chapter 2, Making Harmful Traditional Practices, examines the Ghanaian problematization of cutting as a “harmful traditional practice,” and contextualizes it within governance discourses and policies that conceptualize poverty in northern Ghana as an effect of harmful traditions. It shows that the codification of harmful traditions is embedded in the larger frameworks of modernization and development that have shifted over time. The national discourse of harmful traditions is the primary mode of problematizing northern poverty; it draws on neoliberal technologies of recognizing scarcity while shifting the responsibility for it to northern Ghanaians and their traditions. I suggest that anti-cutting campaigns employ this notion to mediate the fraught relationship between Ghana’s North and South and the place of the North in the Ghanaian polity. I suggest that the public embrace of this problematization results from the construction of northern Ghana as a counterpoint to southern civilization and modernity and a site for displacing national lack, shame, and disorder.

The last glaciation of Marvin Peninsula, northern Ellesmere Island, High Arctic, Canada

1989 ◽  
Vol 26 (12) ◽  
pp. 2578-2590 ◽  
Author(s):  
Donald S. Lemmen
Keyword(s):  
High Arctic ◽  
Ellesmere Island ◽  
North Coast ◽  
Radiocarbon Dates ◽  
The North ◽  
Last Glaciation ◽  
Ice Retreat ◽  
Late Wisconsinan ◽  
Glaciomarine Sediments ◽  
North And South

The limit of the last glaciation on Marvin Peninsula, northernmost Ellesmere Island, is recorded by extensive ice-marginal landforms and early Holocene glaciomarine sediments. While glaciers occupied most valleys on the peninsula, other areas remained ice free, as did most of the adjacent fiords. Beyond the ice limit, sparse erratics and degraded meltwater channels within weathered bedrock are evidence of older, more extensive glaciation(s). Shorelines and marine shells 50 m above the limit of the Holocene sea along the north coast relate to these older glacial events.Thirty-four new radiocarbon dates provide a chronology of ice buildup and retreat. Glaciers reached their limit after 23 ka, and locally as late as 11 ka. This was achieved by both expansion of existing glaciers and accumulation on plateau and lowland sites, which are presently ice free. Late Wisconsinan climate was characterized by cold and extreme aridity. Five dates ranging from 11 to 31 ka BP on subfossil bryophytes suggest that ice-free areas were biologically productive throughout the last glaciation. Ice retreat and postglacial emergence had begun by 9.5 ka and was associated with a marked climatic amelioration. The deglacial chronology confirms a pronounced disparity in the timing of ice retreat on the north and south sides of the Grant Land Mountains.

Synopsis of the Nearctic Species of Stenodema Laporte, and Description of a New Species from Western Canada (Hemiptera: Miridae)

1961 ◽  
Vol 93 (6) ◽  
pp. 450-455 ◽  
Author(s):  
Leonard A. Kelton
Keyword(s):  
New Species ◽  
North America ◽  
American Literature ◽  
North American ◽  
Male Genitalia ◽  
Western Canada ◽  
The North ◽  
A New Species ◽  
Male Genital

Recent study of the male genitalia in the Miridae (Kelton, 1959) showed that the Palearctic Stenodema virens (L.) does not occur in North America. The six other species that have been reported in the North American literature are: dorsolis (Say), vicinum (Prov.), trispinosum Reut., sequoiae Bliven, falki Bliven, and imperii Bliven. The three species described by Bliven (1955, 1958) were not available to me for study, however, Bliven (1960) has recently published a paper containing figures of the male genital claspers of these species. These appear to differ considerably from those of virens, vicinum and trispinosum as well as amongst themselves.

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