Past and future sky-island dynamics of tropical mountains: A model for two Geotrupes (Coleoptera: Geotrupidae) species in Oaxaca, Mexico

The Holocene ◽  
2020 ◽  
Vol 30 (10) ◽  
pp. 1462-1470 ◽  
Author(s):  
Alfonsina Arriaga-Jiménez ◽  
Bert Kohlmann ◽  
Lorenzo Vázquez-Selem ◽  
Yhenner Umaña ◽  
Matthias Rös
Keyword(s):  
Dynamic Process ◽  
Late Quaternary ◽  
Continuous Distribution ◽  
Ice Age ◽  
Mountain Range ◽  
Tropical Mountains ◽  
Quaternary Glaciation ◽  
Mountain System ◽  
Genetic Differentiation Of Populations ◽  
Sky Island

Recent collecting and taxonomic studies of dung beetles of the genus Geotrupes Latreille (Coleoptera: Geotrupidae) in the mountains of Oaxaca have evidenced the existence of a vicariant speciation pattern, where one species occupies the northern mountain system and the other one the southern mountain range. A study of this possible vicariant speciation mechanism is presented using a paleobiogeographic mapping analysis of both Geotrupes species distribution during Late Quaternary glaciation events. Based on these paleomaps a possible speciation mechanism (vicariant speciation) is suggested, in which one common ancestor (mother species) lived at the bottom of the Valle de Oaxaca (Oaxaca Valley) during the last local glacial maximum (LLGM, 21-17.5 kyr) and whose possible continuous distribution was broken into two (or more) separated areas on mountaintops as the climate became warmer toward the present. We propose that the fragmentation and isolation of habitats may have promoted genetic differentiation of populations resulting in vicariant speciation, as suggested by a sky-island dynamic process. The example of a possible effect of the Little Ice Age in the mountains of Oaxaca is also discussed. Finally, a projection is made into the XXII century, based on climatic modeling predictions. These last results suggest the possible disappearance of the sky-island dynamic process through the accelerated speed of climatic change.

Subdivision of Glacial Deposits in Southeastern Peru Based on Pedogenic Development and Radiometric Ages

2001 ◽  
Vol 56 (1) ◽  
pp. 31-50 ◽  
Author(s):  
Adam Y. Goodman ◽  
Donald T. Rodbell ◽  
Geoffrey O. Seltzer ◽  
Bryan G. Mark
Keyword(s):  
Chemical Weathering ◽  
Late Quaternary ◽  
Laboratory Data ◽  
Ice Age ◽  
Tropical Andes ◽  
Southern Peru ◽  
Ice Cap ◽  
Quaternary Glaciation ◽  
Quelccaya Ice Cap ◽  
Age Estimates

AbstractThe Cordillera Vilcanota and Quelccaya Ice Cap region of southern Peru (13°30′–14°00′S; 70°40′–71°25′W) contains a detailed record of late Quaternary glaciation in the tropical Andes. Quantification of soil development on 19 moraine crests and radiocarbon ages are used to reconstruct the glacial history. Secondary iron and clay increase linearly in Quelccaya soils and clay accumulates at a linear rate in Vilcanota soils, which may reflect the semicontinuous addition of eolian dust enriched in secondary iron to all soils. In contrast, logarithmic rates of iron buildup in soils in the Cordillera Vilcanota reflect chemical weathering; high concentrations of secondary iron in Vilcanota tills may mask the role of eolian input to these soils. Soil-age estimates from extrapolation of field and laboratory data suggest that the most extensive late Quaternary glaciation occurred >70,000 yr B.P. This provides one of the first semiquantitative age estimates for maximum ice extent in southern Peru and is supported by a minimum-limiting age of ∼41,520 14C yr B.P. A late glacial readvance culminated ∼16,650 cal yr B.P. in the Cordillera Vilcanota. Following rapid deglaciation of unknown extent, an advance of the Quelccaya Ice Cap occurred between ∼13,090 and 12,800 cal yr B.P., which coincides approximately with the onset of the Younger Dryas cooling in the North Atlantic region. Moraines deposited <394 cal yr B.P. in the Cordillera Vilcanota and <300 cal yr B.P. on the west side of the Quelccaya Ice Cap correlate with Little Ice Age moraines of other regions.

Late Quaternary river terraces in the Central Mountain Range of Taiwan: A study of cover sediments across a terrace section along the Tachia River

2012 ◽  
Vol 263 ◽  
pp. 26-36 ◽  
Author(s):  
Dirk Wenske ◽  
Manfred Frechen ◽  
Margot Böse ◽  
Tony Reimann ◽  
Chia-Han Tseng ◽  
...  
Keyword(s):  
Late Quaternary ◽  
Mountain Range ◽  
River Terraces

Ice Age Earth: Late Quaternary Geology and Climate

1994 ◽  
Vol 160 (2) ◽  
pp. 212
Author(s):  
Neil Roberts ◽  
Alastair G. Dawson
Keyword(s):  
Late Quaternary ◽  
Quaternary Geology ◽  
Ice Age

Chronology of late Quaternary glaciation in the Pindar valley, Alaknanda basin, Central Himalaya (India)

2013 ◽  
Vol 66 ◽  
pp. 224-233 ◽  
Author(s):  
Rameshwar Bali ◽  
S. Nawaz Ali ◽  
K.K. Agarwal ◽  
Saurabh Kumar Rastogi ◽  
Kalyan Krishna ◽  
...  
Keyword(s):  
Late Quaternary ◽  
Central Himalaya ◽  
Quaternary Glaciation

Late Quaternary vegetation of the Aleutian Islands, southwestern Alaska

1990 ◽  
Vol 68 (6) ◽  
pp. 1320-1326 ◽  
Author(s):  
Calvin J. Heusser
Keyword(s):  
Late Quaternary ◽  
Thickness Distribution ◽  
Patch Dynamics ◽  
Volcanic Eruptions ◽  
Ice Age ◽  
Aleutian Islands ◽  
Fossil Pollen ◽  
History Of ◽  
Tephra Layers ◽  
Radiocarbon Chronology

Late Quaternary vegetational history of the Aleutian Islands is interpreted from fossil pollen and spore stratigraphy and radiocarbon chronology of sections of mires on the islands of Attu, Adak, Atka, and Umnak. Mires postdate the withdrawal of ice-age glaciers between approximately 12 000 and 10 000 years ago with the exception of the mire on Attu Island, where deglaciation apparently began as late as 7000 years ago. No uniform pattern of change in Pacific coastal tundra communities is evident in the fossil assemblages. Pollen assemblages, consisting variably of Gramineae, Cyperaceae, Empetrum, Umbelliferae, Salix, Ranunculaceae, Compositae, Polypodiaceae, and Lycopodium, reflect conditions in effect in different sectors of the Aleutian chain. Climate, soil, topography, volcanism, and seismic activity are noteworthy parameters influencing vegetation composition and distribution. Volcanism has been of major importance, as shown by thickness, distribution, and frequency of tephra layers that number 5 on Attu, 24 on Adak, 17 on Atka, and 5 on Umnak. A repeated condition of patch dynamics, created in the main by recurrent volcanic eruptions with widespread accompanying ashfalls, has apparently overprinted the effects of climatic change. Key words: Aleutian Islands, Quaternary, vegetation, fossil pollen, volcanism.

Paleoecology and Late Quaternary Environments of the Colorado Rockies

2001 ◽  
Author(s):  
Scott A. Elias
Keyword(s):  
North America ◽  
Late Quaternary ◽  
Ice Sheets ◽  
Ice Sheet ◽  
Rocky Mountain ◽  
Mountain Region ◽  
Ice Age ◽  
Rocky Mountain Region ◽  
Last Ice Age ◽  
Teton Range

Present-day environments cannot be completely understood without knowledge of their history since the last ice age. Paleoecological studies show that the modern ecosystems did not spring full-blown onto the Rocky Mountain region within the last few centuries. Rather, they are the product of a massive reshuffling of species that was brought about by the last ice age and indeed continues to this day. Chronologically, this chapter covers the late Quaternary Period: the last 25,000 years. During this interval, ice sheets advanced southward, covering Canada and much of the northern tier of states in the United States. Glaciers crept down from mountaintops to fill high valleys in the Rockies and Sierras. The late Quaternary interval is important because it bridges the gap between the ice-age world and modern environments and biota. It was a time of great change, in both physical environments and biological communities. The Wisconsin Glaciation is called the Pinedale Glaciation in the Rocky Mountain region (after terminal moraines near the town of Pinedale, Wyoming; see chapter 4). The Pinedale Glaciation began after the last (Sangamon) Interglaciation, perhaps 110,000 radiocarbon years before present (yr BP), and included at least two major ice advances and retreats. These glacial events took different forms in different regions. The Laurentide Ice Sheet covered much of northeastern and north-central North America, and the Cordilleran Ice Sheet covered much of northwestern North America. The two ice sheets covered more than 16 million km2 and contained one third of all the ice in the world’s glaciers during this period. The history of glaciation is not as well resolved for the Colorado Front Range region as it is for regions farther north. For instance, although a chronology of three separate ice advances has been established for the Teton Range during Pinedale times, in northern Colorado we know only that there were earlier and later Pinedale ice advances. We do not know when the earlier advance (or multiple advances) took place. However, based on geologic evidence (Madole and Shroba 1979), the early Pinedale glaciation was more extensive than the late Pinedale was.

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