Late Quaternary Vegetational History of the North York Moors. V. The Cleveland Dales

1977 ◽  
Vol 4 (4) ◽  
pp. 353 ◽  
Author(s):  
R. L. Jones
Keyword(s):  
Late Quaternary ◽  
The North ◽  
History Of

Molecular systematics and phylogeography of a widespread Neotropical avian lineage: evidence for cryptic speciation with protracted gene flow throughout the Late Quaternary

2020 ◽  
Author(s):  
Leonardo S Miranda ◽  
Bernardo O Prestes ◽  
Alexandre Aleixo
Keyword(s):  
Gene Flow ◽  
Incomplete Lineage Sorting ◽  
Late Quaternary ◽  
Integrative Approach ◽  
Lineage Sorting ◽  
Distribution Models ◽  
The North ◽  
History Of ◽  
Andean South America ◽  
Spatio Temporal

Abstract Here we use an integrative approach, including coalescent-based methods, isolation–migration and species distribution models, to infer population structure, divergence times and diversification in the two species of the genus Cymbilaimus (Aves, Thamnophilidae). Our results support a recent and rapid diversification with both incomplete lineage sorting and gene flow shaping the evolutionary history of Cymbilaimus. The spatio-temporal pattern of cladogenesis suggests that Cymbilaimus originated in the north/western portion of cis-Andean South America and then diversified into the Brazilian Shield and Central America after consolidation of the modern Amazonian drainage and the Andean range. This evolutionary scenario is explained by cycles of range expansion and dispersal, followed by isolation, and recurrent gene flow, during the last 1.2 Myr. Our results agree with those recently reported for other closely related suboscine lineages, whereby the window of introgression between closely related taxa remains open for up to a few million years after their original split. In Cymbilaimus, introgression was recurrent between C. lineatus and C. sanctaemariae, even after they acquired vocal and ecological differentiation, supporting the claim that at least in Neotropical suboscines, full reproductive compatibility may take millions of years to evolve and cannot be interpreted as synonymous with a lack of speciation.

Spatio-temporal behaviour of continental transform faults: implications from the late Quaternary slip history of the North Anatolian Fault, Turkey

2019 ◽  
Vol 56 (11) ◽  
pp. 1218-1238 ◽  
Author(s):  
Cengiz Zabcı
Keyword(s):  
Shear Zone ◽  
Late Quaternary ◽  
Slip Rate ◽  
Secondary Structures ◽  
North Anatolian Fault ◽  
Marmara Region ◽  
Temporal Behaviour ◽  
The North ◽  
Slip History ◽  
History Of

The slip history of the North Anatolian Fault (NAF) is constrained by displacement and age data for the last 550 ka. First, I classified all available geological estimates as members of three groups: Model I for the eastern, Model II for the central, and Model III for the western segments where the North Anatolian Shear Zone gradually widens from east to west. The short-term uniform slip solutions yield similar results, 17.5 +4/–3.5 mm/a, 18.9 +3.7/–3.3 mm/a, and 16.9 +1.2/–1.1 mm/a from east to the west. Although these model rates do not show any significant spatial variations among themselves, the correlation with geodetic estimates, ranging between 15 mm/a and 28 mm/a for different sections of the NAF, displays significant discrepancies especially for the central and western segments of the fault. Discrepancies suggest that most strain is accumulated along the NAF, but some portion of it is distributed along secondary structures of the North Anatolian Shear Zone. The deformation rate is constant at least for the last 195 ka, whereas the limited number of data show strain transfer from northern to the southern strand between 195 and 320 ka BP in the Marmara Region when the incremental slip rate decreases to 13.2 +3.1/–2.9 mm/a for the northern strand of the NAF. Considering the possible uncertainties of incremental displacements and their timings, more studies on slip rate are needed at different sites, including major structural elements of the North Anatolian Shear Zone. Although most of the strain is localized along the main displacement zone, the NAF, secondary structures are still capable of generating earthquakes that can hardly reach Mw 7.

The late Quaternary history of lodgepole and jack pines

1985 ◽  
Vol 15 (5) ◽  
pp. 749-772 ◽  
Author(s):  
William B. Critchfield
Keyword(s):  
Late Quaternary ◽  
Jack Pine ◽  
The North ◽  
Last Glaciation ◽  
Variation Patterns ◽  
History Of ◽  
Quaternary History ◽  
Fossil Records ◽  
The Last Glacial Maximum ◽  
The Last Glacial

Lodgepole and jack pines (Pinuscontorta Dougl. ex. Loud. and Pinusbanksiana Lamb.), components of the North American boreal forest, have pioneering roles after major disturbances such as fire or glaciation. These species are closely related and hybridize in western Canada, but their fossil records and contemporary variation patterns suggest they had completely different late Quaternary histories. Several taxonomically recognized geographic races of lodgepole pine apparently survived the last glaciation without drastic modification, the northern races either persisting in far-northern refugia or migrating from the south. The uneven influence of jack pine on northern lodgepole populations implies repeated genetic contacts, but less marked introgression in the other direction could be of post-Pleistocene origin. Jack pine occupied its entire range after the last glacial maximum and lacks taxonomically recognized races. In the Great Lakes region, however, the presence of regionally distinct populations suggests the species had at least two Midwestern refugia. This hypothesis is contrary to the widely held view that jack pine occupied most or all of its range from a well-documented refugium in southeastern North America, but is supported by limited fossil evidence that pine persisted in the Midwest during the last glaciation.

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