Land plant evolution decreased, rather than increased, weathering rates

Geology ◽  
2019 ◽  
Vol 48 (1) ◽  
pp. 29-33 ◽  
Author(s):  
Michael P. D’Antonio ◽  
Daniel E. Ibarra ◽  
C. Kevin Boyce
Keyword(s):  
Organic Carbon ◽  
Carbon Cycle ◽  
Land Plant ◽  
Plant Evolution ◽  
Land Plants ◽  
Silicate Weathering ◽  
Weathering Rates ◽  
Carbon Burial ◽  
Land Plant Evolution ◽  
Volcanic Outgassing

Abstract The repeated evolution of trees is widely thought to have enhanced the capacity of silicate weathering via the impact of deep rooting. However, land plants are also responsible for wetland assembly and organic carbon burial. The total burial output of carbon via both organic and inorganic deposition must balance input to the exogenic system from volcanic outgassing on million-year time scales. Increased partitioning of carbon burial toward organic carbon and away from inorganic carbon reduces the marine carbonate burial flux, necessitating a lowered total flux of alkalinity to the oceans to maintain mass balance in the Earth’s surface carbon cycle. This flux includes the nutrient delivery from the terrestrial vegetation implicated as a driver of marine evolution, extinction, and environmental change including anoxia and black shale formation. Here, the burial of terrestrial organic carbon, first substantially in the Devonian and continuing through to the present, is argued to require a reduction in silicate weathering rates when compared to earlier times, given the independence of volcanic outgassing from weathering on short time scales. Land plants still may cause reductions in steady-state atmospheric CO2 levels, but via increasing the silicate weathering feedback strength, not silicate weathering rates. The mass-balance constraints on the long-term carbon cycle provide a mechanism for linking how land plant evolution simultaneously increased nutrient recycling and weathering efficiency of the Earth’s surface.

Modeling the consequences of land plant evolution on silicate weathering

2019 ◽  
Vol 319 (1) ◽  
pp. 1-43 ◽  
Author(s):  
Daniel E. Ibarra ◽  
Jeremy K. Caves Rugenstein ◽  
Aviv Bachan ◽  
Andrés Baresch ◽  
Kimberly V. Lau ◽  
...  
Keyword(s):  
Land Plant ◽  
Plant Evolution ◽  
Silicate Weathering ◽  
Land Plant Evolution

Age of the Cedarberg Formation, South Africa and early land plant evolution

1986 ◽  
Vol 123 (4) ◽  
pp. 445-454 ◽  
Author(s):  
J. Gray ◽  
J. N. Theron ◽  
A. J. Boucot
Keyword(s):  
South Africa ◽  
Land Plant ◽  
Plant Evolution ◽  
Marine Phytoplankton ◽  
Land Plants ◽  
Table Mountain ◽  
Plant Remains ◽  
First Occurrence ◽  
Land Plant Evolution ◽  
Early Land

AbstractThe first occurrence of Early Paleozoic land plants is reported from South Africa. The plant remains are small, compact tetrahedral spore tetrads. They occur abundantly in the Soom Shale Member of the Cedarberg Formation, Table Mountain Group. Marine? phytoplankton (sphaeromorphs or leiospheres) occur with the spore tetrads in all samples. Rare chitinozoans are found in half the samples. Together with similar spore tetrads from the Paraná Basin (Gray et al. 1985) these are the first well-documented records of Ashgill and/or earlier Llandovery land plants from the Malvinokaffric Realm, and from the African continent south of Libya. These spore tetrads have botanical, evolutionary, and biogeographic significance. Their size in comparison with spore tetrads from stratigraphic sections throughout eastern North America, suggests that an earliest Llandovery age is more probable for the Soom Shale Member, although a latest Ordovician age cannot be discounted. The age of the brachiopods in the overlying Disa Siltstone Member has been in contention for over a decade. Both Ashgillian and Early Llandovery ages have been proposed. The age of the underlying Soom Shale Member based on plant spores and trilobites (earliest Llandovery or latest Ashgillian) suggests that the Disa Siltstone Member is also likely to be of Early Llandovery age, although the distance between the Soom Shale Member spore-bearing locality and rocks to the south yielding abundant invertebrate body fossils at one locality is great enough to permit diachroneity.

scholarly journals The timescale of early land plant evolution

2018 ◽  
Vol 115 (10) ◽  
pp. E2274-E2283 ◽  
Author(s):  
Jennifer L. Morris ◽  
Mark N. Puttick ◽  
James W. Clark ◽  
Dianne Edwards ◽  
Paul Kenrick ◽  
...  
Keyword(s):  
Molecular Clock ◽  
Fossil Record ◽  
Land Plant ◽  
Plant Evolution ◽  
Land Plants ◽  
Early Land Plant ◽  
Land Plant Evolution ◽  
The Impact ◽  
Earth’S System ◽  
Early Land

Establishing the timescale of early land plant evolution is essential for testing hypotheses on the coevolution of land plants and Earth’s System. The sparseness of early land plant megafossils and stratigraphic controls on their distribution make the fossil record an unreliable guide, leaving only the molecular clock. However, the application of molecular clock methodology is challenged by the current impasse in attempts to resolve the evolutionary relationships among the living bryophytes and tracheophytes. Here, we establish a timescale for early land plant evolution that integrates over topological uncertainty by exploring the impact of competing hypotheses on bryophyte−tracheophyte relationships, among other variables, on divergence time estimation. We codify 37 fossil calibrations for Viridiplantae following best practice. We apply these calibrations in a Bayesian relaxed molecular clock analysis of a phylogenomic dataset encompassing the diversity of Embryophyta and their relatives within Viridiplantae. Topology and dataset sizes have little impact on age estimates, with greater differences among alternative clock models and calibration strategies. For all analyses, a Cambrian origin of Embryophyta is recovered with highest probability. The estimated ages for crown tracheophytes range from Late Ordovician to late Silurian. This timescale implies an early establishment of terrestrial ecosystems by land plants that is in close accord with recent estimates for the origin of terrestrial animal lineages. Biogeochemical models that are constrained by the fossil record of early land plants, or attempt to explain their impact, must consider the implications of a much earlier, middle Cambrian–Early Ordovician, origin.

scholarly journals The evolution of land plants: a perspective from horizontal gene transfer

2014 ◽  
Vol 83 (4) ◽  
pp. 363-368 ◽  
Author(s):  
Qia Wang ◽  
Hang Sun ◽  
Jinling Huang
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Land Plant ◽  
Plant Evolution ◽  
Land Plants ◽  
Plant Colonization ◽  
Mitochondrial Genome Evolution ◽  
Land Plant Evolution ◽  
Colonization Of Land

Recent studies suggest that horizontal gene transfer (HGT) played a significant role in the evolution of eukaryotic lineages. We here review the mechanisms of HGT in plants and the importance of HGT in land plant evolution. In particular, we discuss the role of HGT in plant colonization of land, phototropic response, C<sub>4</sub> photosynthesis, and mitochondrial genome evolution.

scholarly journals Origin of gibberellin-dependent transcriptional regulation by molecular exploitation of a transactivation domain in DELLA proteins

2018 ◽  
Author(s):  
Jorge Hernández-García ◽  
Asier Briones-Moreno ◽  
Renaud Dumas ◽  
Miguel A. Blázquez
Keyword(s):  
Vascular Plants ◽  
Current Knowledge ◽  
Land Plant ◽  
Plant Evolution ◽  
Land Plants ◽  
Transactivation Domain ◽  
Della Proteins ◽  
Co Activation ◽  
Duplication Events ◽  
Land Plant Evolution

AbstractDELLA proteins are land-plant specific transcriptional regulators known to interact through their C-terminal GRAS domain with over 150 transcription factors in Arabidopsis thaliana. Besides, DELLAs from vascular plants can interact through the N-terminal domain with the gibberellin receptor encoded by GID1, through which gibberellins promote DELLA degradation. However, this regulation is absent in non-vascular land plants, which lack active gibberellins or a proper GID1 receptor. Current knowledge indicates that DELLAs are important pieces of the signalling machinery of vascular plants, especially angiosperms, but nothing is known about DELLA function during early land plant evolution or if they exist at all in charophytan algae. We have now elucidated the evolutionary origin of DELLA proteins, showing that algal GRAS proteins are monophyletic and evolved independently from those of land plants, which explains why there are no DELLAs outside land plants. DELLA genes have been maintained throughout land plant evolution with only two major duplication events kept among plants. Furthermore, we show that the features needed for DELLA interaction with the receptor were already present in the ancestor of all land plants, and propose that these DELLA N-terminal motifs have been tightly conserved in non-vascular land plants for their function in transcriptional co-activation, which allowed subsequent exaptation for the interaction with the GID1 receptor when vascular plants developed gibberellin synthesis and the corresponding perception module.

A new species Danaea (Marattiaceae) from the Atlantic forests of Brazil

Phytotaxa ◽  
2018 ◽  
Vol 356 (3) ◽  
pp. 226
Author(s):  
MAARTEN J. M. CHRISTENHUSZ ◽  
ERTON M. ALMEIDA ◽  
LEONARDO P. FELIX
Keyword(s):  
New Species ◽  
Land Plant ◽  
Plant Evolution ◽  
Land Plants ◽  
The Past ◽  
Important Link ◽  
The Family ◽  
Land Plant Evolution ◽  
A New Species

With a long fossil history (Taylor, Taylor & Krings 2009), Marattiaceae are among the earliest lineages of vascular land plants and are an important link to understanding land plant evolution. The family currently has a pantropical distribution, but was more widely distributed in the past. In the neotropics the family is represented by the genera Marattia Swartz (1788: 128), Eupodium Smith (1841: 190) and Danaea Smith (1793: 420). An additional three genera are found in the paleotropics and in total the family has an estimated 135 known species (Christenhusz & Byng 2016).

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