scholarly journals Eolian stratigraphic record of environmental change through geological time

Geology ◽  
2021 ◽  
Author(s):  
G.I.E. Cosgrove ◽  
L. Colombera ◽  
N.P. Mountney

The terrestrial sedimentary record provides a valuable archive of how ancient depositional systems responded to and recorded changes in Earth’s atmosphere, biosphere, and geosphere. However, the record of these environmental changes in eolian sedimentary successions is poorly constrained and largely unquantified. Our study presents the first global-scale, quantitative investigation of the architecture of eolian systems through geological time via analysis of 55 case studies of eolian successions. Eolian deposits accumulating (1) under greenhouse conditions, (2) in the presence of vascular plants and grasses, and (3) in rapidly subsiding basins associated with the rifting of supercontinents are represented by significantly thicker eolian dune-set, sand-sheet, and interdune architectural elements. Pre-vegetation eolian systems are also associated with more frequent interactions with non-eolian environments. The interplay of these forcings has resulted in dune-set thicknesses that tend to be smallest and largest in Proterozoic and Mesozoic successions, respectively. In the Proterozoic, the absence of sediment-binding plant roots rendered eolian deposits susceptible to post-depositional wind deflation and reworking by fluvial systems, whereby highly mobile channels reworked contiguous eolian deposits. During the Mesozoic, humid greenhouse conditions (associated with relatively elevated water tables) and high rates of basin subsidence (associated with the breakup of Pangea) favored the rapid transfer of eolian sediment beneath the erosional baseline. The common presence of vegetation promoted accumulation of stabilizing eolian systems. These factors acted to limit post-depositional reworking. Eolian sedimentary deposits record a fingerprint of major environmental changes in Earth history: climate, continental configuration, tectonics, and land-plant evolution.

2019 ◽  
Vol 286 (1914) ◽  
pp. 20191662 ◽  
Author(s):  
James W. Clark ◽  
Mark N. Puttick ◽  
Philip C. J. Donoghue

Whole-genome duplication (WGD) has occurred commonly in land plant evolution and it is often invoked as a causal agent in diversification, phenotypic and developmental innovation, as well as conferring extinction resistance. The ancient and iconic lineage of Equisetum is no exception, where WGD has been inferred to have occurred prior to the Cretaceous–Palaeogene (K–Pg) boundary, coincident with WGD events in angiosperms. In the absence of high species diversity, WGD in Equisetum is interpreted to have facilitated the long-term survival of the lineage. However, this characterization remains uncertain as these analyses of the Equisetum WGD event have not accounted for fossil diversity. Here, we analyse additional available transcriptomes and summarize the fossil record. Our results confirm support for at least one WGD event shared among the majority of extant Equisetum species. Furthermore, we use improved dating methods to constrain the age of gene duplication in geological time and identify two successive Equisetum WGD events. The two WGD events occurred during the Carboniferous and Triassic, respectively, rather than in association with the K–Pg boundary. WGD events are believed to drive high rates of trait evolution and innovations, but analysed trends of morphological evolution across the historical diversity of Equisetum provide little evidence for further macroevolutionary consequences following WGD. WGD events cannot have conferred extinction resistance to the Equisetum lineage through the K–Pg boundary since the ploidy events occurred hundreds of millions of years before this mass extinction and we find evidence of extinction among fossil polyploid Equisetum lineages. Our findings precipitate the need for a review of the proposed roles of WGDs in biological innovation and extinction survival in angiosperm and non-angiosperm lineages alike.


Author(s):  
Anita Roth-Nebelsick ◽  
Tatiana Miranda ◽  
Martin Ebner ◽  
Wilfried Konrad ◽  
Christopher Traiser

AbstractTrees are the fundamental element of forest ecosystems, made possible by their mechanical qualities and their highly sophisticated conductive tissues. The evolution of trees, and thereby the evolution of forests, were ecologically transformative and affected climate and biogeochemical cycles fundamentally. Trees also offer a substantial amount of ecological niches for other organisms, such as epiphytes, creating a vast amount of habitats. During land plant evolution, a variety of different tree constructions evolved and their constructional principles are a subject of ongoing research. Understanding the “natural construction” of trees benefits strongly from methods and approaches from physics and engineering. Plant water transport is a good example for the ongoing demand for interdisciplinary efforts to unravel form-function relationships on vastly differing scales. Identification of the unique mechanism of water long-distance transport requires a solid basis of interfacial physics and thermodynamics. Studying tree functions by using theoretical approaches is, however, not a one-sided affair: The complex interrelationships between traits, functionality, trade-offs and phylogeny inspire engineers, physicists and architects until today.


2013 ◽  
Vol 2013 ◽  
pp. 1-14 ◽  
Author(s):  
Maria S. Krasnikova ◽  
Denis V. Goryunov ◽  
Alexey V. Troitsky ◽  
Andrey G. Solovyev ◽  
Lydmila V. Ozerova ◽  
...  

PCR-based approach was used as a phylogenetic profiling tool to probe genomic DNA samples from representatives of evolutionary distant moss taxa, namely, classes Bryopsida, Tetraphidopsida, Polytrichopsida, Andreaeopsida, and Sphagnopsida. We found relatives of allPhyscomitrella patensmiR390 and TAS3-like loci in these plant taxa excluding Sphagnopsida. Importantly, cloning and sequencing ofMarchantia polymorphagenomic DNA showed miR390 and TAS3-like sequences which were also found among genomic reads ofM. polymorphaat NCBI database. Our data suggest that the ancient plant miR390-dependent TAS molecular machinery firstly evolved to target AP2-like mRNAs in Marchantiophyta and only then both ARF- and AP2-specific mRNAs in mosses. The presented analysis shows that moss TAS3 families may undergone losses of tasiAP2 sites during evolution toward ferns and seed plants. These data confirm that miR390-guided genes coding for ARF- and AP2-specific ta-siRNAs have been gradually changed during land plant evolution.


2021 ◽  
Author(s):  
Eftychios Frangedakis ◽  
Manuel Waller ◽  
Tomoaki Nishiyama ◽  
Hirokazu Tsukaya ◽  
Xia Xu ◽  
...  

We have developed a simple Agrobacterium-mediated method for the stable transformation of the hornwort Anthoceros agrestis, the fifth bryophyte species for which a genetic manipulation technique becomes available. High transformation efficiency was achieved by using thallus tissue grown under low-light conditions. We generated a total of 216 transgenic A. agrestis lines expressing the β-Glucuronidase (GUS), cyan, green, and yellow fluorescent proteins under the control of the CaMV 35S promoter and several endogenous promoters. Nuclear and plasma membrane localization with multiple color fluorescent proteins was also confirmed. The transformation technique described here should pave the way for detailed molecular and genetic studies of hornwort biology, providing much needed insight into the molecular mechanisms underlying symbiosis, carbon-concentrating mechanism, RNA editing, and land plant evolution in general.


2010 ◽  
Vol 365 (1558) ◽  
pp. 3667-3679 ◽  
Author(s):  
Michael J. Benton

Comparative studies of large phylogenies of living and extinct groups have shown that most biodiversity arises from a small number of highly species-rich clades. To understand biodiversity, it is important to examine the history of these clades on geological time scales. This is part of a distinct ‘phylogenetic expansion’ view of macroevolution, and contrasts with the alternative, non-phylogenetic ‘equilibrium’ approach to the history of biodiversity. The latter viewpoint focuses on density-dependent models in which all life is described by a single global-scale model, and a case is made here that this approach may be less successful at representing the shape of the evolution of life than the phylogenetic expansion approach. The terrestrial fossil record is patchy, but is adequate for coarse-scale studies of groups such as vertebrates that possess fossilizable hard parts. New methods in phylogenetic analysis, morphometrics and the study of exceptional biotas allow new approaches. Models for diversity regulation through time range from the entirely biotic to the entirely physical, with many intermediates. Tetrapod diversity has risen as a result of the expansion of ecospace, rather than niche subdivision or regional-scale endemicity resulting from continental break-up. Tetrapod communities on land have been remarkably stable and have changed only when there was a revolution in floras (such as the demise of the Carboniferous coal forests, or the Cretaceous radiation of angiosperms) or following particularly severe mass extinction events, such as that at the end of the Permian.


The Holocene ◽  
2018 ◽  
Vol 28 (6) ◽  
pp. 984-997 ◽  
Author(s):  
Andrea JM Hanna ◽  
Timothy M Shanahan ◽  
Mead A Allison ◽  
Thomas S Bianchi ◽  
Kathryn M Schreiner

The significant and ongoing environmental changes in Arctic regions demonstrate the need for quantitative, high-resolution records of pre-industrial climate change in this climatically sensitive region; such records are fundamental for understanding recent anthropogenic changes in the context of natural variability. Sediment contained within Arctic coastal environments proximal to large fluvial systems has the ability to record paleoclimate variability on subdecadal to decadal scale resolution, on par with many other terrestrial climate archives (i.e. lake sediments, ice cores). Here, we utilize one such sediment archive from Simpson Lagoon, Alaska, located adjacent to the Colville River Delta to reconstruct temperature variability and fluctuations in sediment sourcing over the past 1700 years. Quantitative reconstructions of summer air temperature are obtained using the branched glycerol dialkyl glycerol tetraether (brGDGT)-derived methylation index of branched tetraethers (MBT’)/cyclization ratio of branched tetraether (CBT) paleothermometer and reveal temperature departures correlative with noted climate events (i.e. ‘Little Ice Age’, ‘Medieval Climate Anomaly’). In addition, temporal variability in sediment sourcing to the lagoon, determined using a multi-proxy approach (i.e. granulometry, elemental analysis, clay mineralogy), broadly corresponds with temperature fluctuations, indicating relative increases in fluvial sediment discharge during colder intervals and decreased river discharge/increased coastal erosion during warmer periods. The Simpson Lagoon record presented in this study is the first temperature reconstruction, to our knowledge, developed from coastal marine sediments in the Alaskan Beaufort Sea.


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