scholarly journals Mitochondrial sequence data indicate “Vicariance by Erosion” as a mechanism of species diversification in North American Ptomaphagus (Coleoptera, Leiodidae, Cholevinae) cave beetles

2019 ◽  
Vol 29 ◽  
pp. 35-57 ◽  
Author(s):  
Vincent L. Leray ◽  
Jason Caravas ◽  
Markus Friedrich ◽  
Kirk S. Zigler
Keyword(s):  
Molecular Phylogeny ◽  
Sequence Data ◽  
Single Species ◽  
The South ◽  
Cumberland Plateau ◽  
Climate Fluctuations ◽  
The Past ◽  
Pleistocene Climate ◽  
Group 2 ◽  
Carrion Beetles

Small carrion beetles (Coleoptera: Leiodidae: Cholevinae) are members of cave communities around the world and important models for understanding the colonization of caves, adaptation to cave life, and the diversification of cave-adapted lineages. We developed a molecular phylogeny to examine the diversification of the hirtus-group of the small carrion beetle genus Ptomaphagus. The hirtus-group has no surface-dwelling members; it consists of 19 short-range endemic cave- and soil-dwelling species in the central and southeastern United States of America. Taxonomic, phylogenetic and biogeographic data were previously interpreted to suggest the hirtus-group diversified within the past 350,000 years through a series of cave colonization and speciation events related to Pleistocene climate fluctuations. However, our time-calibrated molecular phylogeny resulting from the analysis of 2,300 nucleotides from five genes across three mitochondrial regions (cox1, cytb, rrnL-trnL-nad1) for all members of the clade paints a different picture. We identify three stages of diversification in the hirtus-group: (1) ~10 million years ago (mya), the lineage that develops into P.shapardi, a soil-dwelling species from the Ozarks, diverged from the lineage that gives rise to the 18 cave-obligate members of the group; (2) between 8.5 mya and 6 mya, seven geographically distinct lineages diverged across Kentucky, Tennessee, Alabama and Georgia; six of these lineages represent a single species today, whereas (3) the ‘South Cumberlands’ lineage in Tennessee and Alabama diversified into 12 species over the past ~6 my. While the events triggering diversification during the first two stages remain to be determined, the distributions, phylogenetic relationships and divergence times in the South Cumberlands lineage are consistent with populations being isolated by vicariant events as the southern Cumberland Plateau eroded and fragmented over millions of years.

Heterocyphelium leucampyx (Arthoniales, Ascomycota): another orphaned mazaediate lichen finds its way home

2017 ◽  
Vol 49 (4) ◽  
pp. 333-345 ◽  
Author(s):  
Dries VAN DEN BROECK ◽  
Robert LÜCKING ◽  
Ester GAYA ◽  
José Luis CHAVES ◽  
Julius B. LEJJU ◽  
...  
Keyword(s):  
Rna Polymerase Ii ◽  
Ribosomal Rna ◽  
Sequence Data ◽  
Parallel Evolution ◽  
Single Species ◽  
Molecular Data ◽  
Small Subunit ◽  
Systematic Position ◽  
The Past ◽  
The Family

AbstractHeterocyphelium is a mazaediate genus containing a single species, H. leucampyx. The species was originally described from Cuba within the genus Trachylia (Arthoniales, Arthoniaceae) and later placed in various genera of the collective order Caliciales s. lat. For the past three decades, Heterocyphelium was considered an orphaned genus (incertae sedis) within the Ascomycota, since morphology alone could not resolve its systematic position. In this study, we added molecular data with the aim of resolving this uncertainty. Bayesian and maximum likelihood analyses of newly generated sequence data from the mitochondrial ribosomal RNA small subunit (mtSSU) and the RNA polymerase II second largest subunit gene (RPB2) provide clear evidence that Heterocyphelium leucampyx is nested within the order Arthoniales, in the family Lecanographaceae, sister to the genus Alyxoria. Heterocyphelium is a further example of parallel evolution of passive spore dispersal, prototunicate asci and the occurrence of a mazaedium in the Ascomycota, and another calicioid genus whose systematic placement could be eventually clarified by means of molecular data. Heterocyphelium is the fourth mazaediate genus in Arthoniales, in addition to Sporostigma, Tylophorella and Tylophoron.

scholarly journals Phylogeography and population genetics of the endemic Malagasy bat,Macronycteris commersonis.s. (Chiroptera: Hipposideridae)

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e5866
Author(s):  
Andrinajoro R. Rakotoarivelo ◽  
Steven M. Goodman ◽  
M. Corrie Schoeman ◽  
Sandi Willows-Munro
Keyword(s):  
Sequence Data ◽  
Phylogeographic Structure ◽  
Climate Conditions ◽  
Climate Fluctuations ◽  
Pleistocene Climate ◽  
Clade B ◽  
Clade C ◽  
Forested Areas ◽  
Open Woodland ◽  
Western Half

Macronycteris commersoni(Hipposideridae), a bat species endemic to Madagascar, is widespread across the island and utilizes a range of habitat types including open woodland, degraded habitats, and forested areas from sea level to 1,325 m. Despite being widely distributed, there is evidence thatM. commersoniexhibits morphological and bioacoustic variation across its geographical range. We investigated the fine-scale phylogeographic structure of populations in the western half of the island using extensive spatial sampling and sequence data from two mitochondrial DNA regions. Our results indicated several lineages withinM. commersoni.Individuals collected from northern Madagascar formed a single monophyletic clade (clade C). A second clade (clade B) included individuals collected from the south-western portion of the island. This second clade displayed more phylogeographical partitioning with differences in mtDNA haplotypes frequency detected between populations collected in different bioclimatic regions. Lineage dispersal, genetic divergence, and timing of expansion events ofM.commersoniwere probably associated with Pleistocene climate fluctuations. Our data suggest that the northern and the central western regions of Madagascar may have acted as refugia for this species during periods of cooler and drier climate conditions associated with the Pleistocene.

scholarly journals PlatMine pillar strength formula for the UG2 Reef

2021 ◽  
Vol 121 (8) ◽  
pp. 1-12
Author(s):  
B.P. Watson ◽  
R.A. Lamos ◽  
D.P. Roberts
Keyword(s):  
South African ◽  
Hard Rock ◽  
Bushveld Complex ◽  
Back Analysis ◽  
The South ◽  
The Past ◽  
Pillar Strength ◽  
Group 2 ◽  
Strength Formula ◽  
Hard Rock Mines

The Upper Group 2 (UG2) chromitite reef is a shallow-dipping stratiform tabular orebody in the South African Bushveld Complex, which strikes for hundreds of kilometres. Mining is extensive, with depths ranging from close-to-surface to 2 500 m. Pillars are widely used to support the open stopes and bords. Little work has been done in the past to determine the strength of pillars on the UG2 Reef and design was done using formulae developed for other hard-rock mines. This has led to oversized pillars with consequent sterilization of ore. In this paper we describe a back-analysis of stable and failed UG2 pillars on the Bushveld platinum mines, and provides a strength formula for UG2 pillars. The formula may be used cautiously on all Bushveld platinum mines with similar geotechnical, geometrical, and geomechanical conditions to the pillars in the database.

Denouement: World Politics, Systemic Leadership, and Climate Change

2018 ◽  
Author(s):  
William R. Thompson ◽  
Leila Zakhirova
Keyword(s):  
Climate Change ◽  
Global Warming ◽  
World Politics ◽  
First Century ◽  
Modern World ◽  
Climate Fluctuations ◽  
The Past ◽  
Agrarian Economy ◽  
Historical Processes

In this final chapter, we conclude by recapitulating our argument and evidence. One goal of this work has been to improve our understanding of the patterns underlying the evolution of world politics over the past one thousand years. How did we get to where we are now? Where and when did the “modern” world begin? How did we shift from a primarily agrarian economy to a primarily industrial one? How did these changes shape world politics? A related goal was to examine more closely the factors that led to the most serious attempts by states to break free of agrarian constraints. We developed an interactive model of the factors that we thought were most likely to be significant. Finally, a third goal was to examine the linkages between the systemic leadership that emerged from these historical processes and the global warming crisis of the twenty-first century. Climate change means that the traditional energy platforms for system leadership—coal, petroleum, and natural gas—have become counterproductive. The ultimate irony is that we thought that the harnessing of carbon fuels made us invulnerable to climate fluctuations, while the exact opposite turns out to be true. The more carbon fuels are consumed, the greater the damage done to the atmosphere. In many respects, the competition for systemic leadership generated this problem. Yet it is unclear whether systemic leadership will be up to the task of resolving it.

scholarly journals Publisher Correction: Record warming at the South Pole during the past three decades

2021 ◽  
Author(s):  
Kyle R. Clem ◽  
Ryan L. Fogt ◽  
John Turner ◽  
Benjamin R. Lintner ◽  
Gareth J. Marshall ◽  
...  
Keyword(s):  
South Pole ◽  
The South ◽  
The Past

scholarly journals Sequence data from isolated lichen-associated melanized fungi enhance delimitation of two new lineages within Chaetothyriomycetidae

2021 ◽  
Vol 20 (7) ◽  
pp. 911-927
Author(s):  
Lucia Muggia ◽  
Yu Quan ◽  
Cécile Gueidan ◽  
Abdullah M. S. Al-Hatmi ◽  
Martin Grube ◽  
...  
Keyword(s):  
Sequence Data ◽  
Single Species ◽  
Sister Group ◽  
Asexual Propagation ◽  
Dna Sequence Data ◽  
Wide Range ◽  
The Family ◽  
Rock Inhabiting Fungi ◽  
Stable Habitat

AbstractLichen thalli provide a long-lived and stable habitat for colonization by a wide range of microorganisms. Increased interest in these lichen-associated microbial communities has revealed an impressive diversity of fungi, including several novel lineages which still await formal taxonomic recognition. Among these, members of the Eurotiomycetes and Dothideomycetes usually occur asymptomatically in the lichen thalli, even if they share ancestry with fungi that may be parasitic on their host. Mycelia of the isolates are characterized by melanized cell walls and the fungi display exclusively asexual propagation. Their taxonomic placement requires, therefore, the use of DNA sequence data. Here, we consider recently published sequence data from lichen-associated fungi and characterize and formally describe two new, individually monophyletic lineages at family, genus, and species levels. The Pleostigmataceae fam. nov. and Melanina gen. nov. both comprise rock-inhabiting fungi that associate with epilithic, crust-forming lichens in subalpine habitats. The phylogenetic placement and the monophyly of Pleostigmataceae lack statistical support, but the family was resolved as sister to the order Verrucariales. This family comprises the species Pleostigma alpinum sp. nov., P. frigidum sp. nov., P. jungermannicola, and P. lichenophilum sp. nov. The placement of the genus Melanina is supported as a lineage within the Chaetothyriales. To date, this genus comprises the single species M. gunde-cimermaniae sp. nov. and forms a sister group to a large lineage including Herpotrichiellaceae, Chaetothyriaceae, Cyphellophoraceae, and Trichomeriaceae. The new phylogenetic analysis of the subclass Chaetothyiomycetidae provides new insight into genus and family level delimitation and classification of this ecologically diverse group of fungi.

scholarly journals Hydroclimate variability in the low-elevation Atacama Desert over the last 2500 yr

2012 ◽  
Vol 8 (1) ◽  
pp. 287-306 ◽  
Author(s):  
E. M. Gayo ◽  
C. Latorre ◽  
C. M. Santoro ◽  
A. Maldonado ◽  
R. De Pol-Holz
Keyword(s):  
Hydrological Cycle ◽  
Atacama Desert ◽  
Plant Macrofossils ◽  
Central Andes ◽  
Tropical Pacific ◽  
Riparian Ecosystems ◽  
Independent Evidence ◽  
Radiocarbon Dates ◽  
Climate Fluctuations ◽  
The Past

Abstract. Paleoclimate reconstructions reveal that Earth system has experienced sub-millennial scale climate changes over the past two millennia in response to internal/external forcing. Although sub-millennial hydroclimate fluctuations have been detected in the central Andes during this interval, the timing, magnitude, extent and direction of change of these events remain poorly defined. Here, we present a reconstruction of hydroclimate variations on the Pacific slope of the central Andes based on exceptionally well-preserved plant macrofossils and associated archaeological remains from a hyperarid drainage (Quebrada Maní, ∼21° S, 1000 m a.s.l.) in the Atacama Desert. During the late Holocene, riparian ecosystems and farming social groups flourished in the hyperarid Atacama core as surface water availability increased throughout this presently sterile landscape. Twenty-six radiocarbon dates indicate that these events occurred between 1050–680, 1615–1350 and 2500–2040 cal yr BP. Regional comparisons with rodent middens and other records suggest that these events were synchronous with pluvial stages detected at higher-elevations in the central Andes over the last 2500 yr. These hydroclimate changes also coincide with periods of pronounced SST gradients in the Tropical Pacific (La Niña-like mode), conditions that are conducive to significantly increased rainfall in the central Andean highlands and flood events in the low-elevation watersheds at inter-annual timescales. Our findings indicate that the positive anomalies in the hyperarid Atacama over the past 2500 yr represent a regional response of the central Andean climate system to changes in the global hydrological cycle at centennial timescales. Furthermore, our results provide support for the role of tropical Pacific sea surface temperature gradient changes as the primary mechanism responsible for climate fluctuations in the central Andes. Finally, our results constitute independent evidence for comprehending the major trends in cultural evolution of prehistoric peoples that inhabited the region.

scholarly journals Our New Cathedrals: Spirituality and Old-Growth Forests in Western Australia

2006 ◽  
Vol 3 (1) ◽  
Author(s):  
David Worth
Keyword(s):  
Social Movements ◽  
Western Australia ◽  
The State ◽  
The South ◽  
Old Growth ◽  
The Past ◽  
South West ◽  
Old Growth Forests ◽  
Heated Debate ◽  
Policy Proposals

Over the past 30 years in Western Australia (WA), there has been heated debate about the future use of the remaining karri and jarrah forests in the south-west of the State. This debate revolves around policy proposals from two social movements: one wants to preserve as much of the remaining old-growth forests as possible, and an opposing movement supports a continued

Brikettfabrik Witznitz: specific indeterminacy – designing for uncertainty

1996 ◽  
Vol 2 (2) ◽  
pp. 18-39 ◽  
Author(s):  
Florian Beigel ◽  
Philip Christou
Keyword(s):  
Urban Regeneration ◽  
Landscape Design ◽  
Design Strategies ◽  
The South ◽  
Two Stage ◽  
The Past ◽  
Design Competition

A two stage international landscape and urban regeneration design competition was held last year for the site of a former Brikettfabrik at Witznitz near Borna in the south Leipzig region of Germany. The design of the winning entry was based on architectural, urban and landscape design strategies developed over the past five years. This paper opens with an introduction to these ideas and related theoretical precedents. There follows a description of the project's context and of the design itself.

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