scholarly journals Revisiting the origin and diversification of vascular plants through a comprehensive Bayesian analysis of the fossil record

2015 ◽  
Vol 207 (2) ◽  
pp. 425-436 ◽  
Author(s):  
Daniele Silvestro ◽  
Borja Cascales‐Miñana ◽  
Christine D. Bacon ◽  
Alexandre Antonelli
Keyword(s):  
Bayesian Analysis ◽  
Fossil Record ◽  
Vascular Plants

scholarly journals The Heavy Links between Geological Events and Vascular Plants Evolution: A Brief Outline

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Aldo Piombino
Keyword(s):  
Fossil Record ◽  
Vascular Plants ◽  
Vascular Plant ◽  
Flowering Plants ◽  
Plant Evolution ◽  
Seed Plants ◽  
Fast Diffusion ◽  
Extinction Rate ◽  
Environmental Condition ◽  
Plant Origin

Since the rise of photosynthesis, life has influenced terrestrial atmosphere, particularly the O2 and the CO2 content (the latter being originally more than 95%), changing the chemistry of waters, atmosphere, and soils. Billions of years after, a far offspring of these first unicellular forms conquered emerging lands, not only completely changing landscape, but also modifying geological cycles of deposition and erosion, many chemical and physical characteristics of soils and fresh waters, and, more, the cycle of various elements. So, there are no doubts that vascular plants modified geology; but it is true that also geology has affected (and, more, has driven) plant evolution. New software, PyRate, has determined vascular plant origin and diversification through a Bayesian analysis of fossil record from Silurian to today, particularly observing their origination and extinction rate. A comparison between PyRate data and geological history suggests that geological events massively influenced plant evolution and that also the rise of nonflowering seed plants and the fast diffusion of flowering plants can be explained, almost partly, with the environmental condition changes induced by geological phenomena.

scholarly journals The microfossil record of early land plants

2000 ◽  
Vol 355 (1398) ◽  
pp. 717-732 ◽  
Author(s):  
Charles H. Wellman ◽  
Jane Gray
Keyword(s):  
Fossil Record ◽  
Vascular Plants ◽  
Major Change ◽  
Land Plant ◽  
Land Plants ◽  
Early Land Plant ◽  
Early Late ◽  
Early Land ◽  
Lines Of Evidence ◽  
Plant Microfossil

Dispersed microfossils (spores and phytodebris) provide the earliest evidence for land plants. They are first reported from the Llanvirn (Mid–Ordovician). More or less identical assemblages occur from the Llanvirn (Mid–Ordovician) to the late Llandovery (Early Silurian), suggesting a period of relative stasis some 40 Myr in duration. Various lines of evidence suggest that these early dispersed microfossils derive from parent plants that were bryophyte–like if not in fact bryophytes. In the late Llandovery (late Early Silurian) there was a major change in the nature of dispersed spore assemblages as the separated products of dyads (hilate monads) and tetrads (trilete spores) became relatively abundant. The inception of trilete spores probably represents the appearance of vascular plants or their immediate progenitors. A little later in time, in the Wenlock (early Late Silurian), the earliest unequivocal land plant megafossils occur. They are represented by rhyniophytoids. It is only from the Late Silurian onwards that the microfossil / megafossil record can be integrated and utilized in interpretation of the flora. Dispersed microfossils are preserved in vast numbers, in a variety of environments, and have a reasonable spatial and temporal fossil record. The fossil record of plant megafossils by comparison is poor and biased, with only a dozen or so known pre–Devonian assemblages. In this paper, the early land plant microfossil record, and its interpretation, are reviewed. New discoveries, novel techniques and fresh lines of inquiry are outlined and discussed.

The Early Cretaceous Apple Bay flora of Vancouver Island: a hotspot of fossil bryophyte diversity

Botany ◽  
2016 ◽  
Vol 94 (9) ◽  
pp. 683-695 ◽  
Author(s):  
Alexandru M.F. Tomescu
Keyword(s):  
British Columbia ◽  
Early Cretaceous ◽  
Fossil Record ◽  
Vascular Plants ◽  
Vancouver Island ◽  
Significant Fraction ◽  
Plant Fossil ◽  
Rock Record ◽  
Preservation Potential ◽  
Better Than

The pre-Cenozoic bryophyte fossil record is significantly sparser than that of vascular plants or Cenozoic bryophytes. This situation has been traditionally attributed to a hypothesized low preservation potential of the plants. However, instances of excellent pre-Cenozoic bryophyte preservation and the results of experiments simulating fossilization contradict this traditional interpretation, suggesting that bryophytes have good preservation potential. Studies of an anatomically preserved Early Cretaceous (Valanginian) plant fossil assemblage on Vancouver Island (British Columbia), at Apple Bay, focusing on the cryptogamic flora, have revealed an abundant bryophyte component. The Apple Bay flora hosts one of the most diverse bryophyte assemblages worldwide, with at least nine distinct moss types (polytrichaceous, leucobryaceous, tricostate), one complex thalloid liverwort, and two other thalloid plants (representing bryophyte or pteridophyte gametophytes), which contribute a significant fraction of biodiversity to the pre-Cenozoic fossil record of bryophytes. These results (i) corroborate previous observations and studies, indicating that the preservation potential of bryophytes is much better than traditionally thought; (ii) indicate that the bryophyte fossil record is incompletely explored and many more bryophyte fossils are hidden in the rock record, awaiting discovery; and (iii) suggest that the paucity of the pre-Cenozoic bryophyte fossil record is primarily a reflection of inadequate paleobryological capacity.

scholarly journals Evolution and development in the origin of major groups of vascular plants

1992 ◽  
Vol 6 ◽  
pp. 280-280
Author(s):  
William E. Stein
Keyword(s):  
Fossil Record ◽  
Vascular Plants ◽  
Vascular Tissue ◽  
Evolutionary Change ◽  
Diagnostic Features ◽  
Phylogenetic Implications ◽  
History Of ◽  
Hormone Influence ◽  
Multicellular Organisms ◽  
Alternate Routes

Among multicellular organisms, the fossil record of vascular plants is, perhaps, uniquely informative about pattern and process leading to the establishment of major groups. Although classifications above the family level remain highly debatable, especially with regard to level, important insight has been gained into external morphology and internal anatomy of the earliest members of the clade, as well as into general patterns of diversification and change in form through time. Despite these advantages, cladistic methods have brought into sharp focus significant problems with important characters at high taxonomic levels. Putative synapomorphies used to diagnose major groups often have conflicting phylogenetic implications which, according to the cladistic paradigm, must be interpreted as homoplasy. From a biological standpoint, however, unrecognized instances of homoplasy in the character set often seem unlikely due to the complexity of the features involved, and the lack of plausible mechanisms producing multiple parallelisms or reversals by means of “known” processes such as adaptation, homeosis, heterochrony, or functional constraint. Added to this are conceptual and practical problems concerning morphological gaps (and what might bridge them) between recognized groups. One of the most interesting challenges to current approaches are enigmatic fossils early in the history of apparent clades exhibiting unprecedented variability in expression of supposedly diagnostic features. As a result, terminology originally developed to circumscribe alternative morphological states within clades completely breaks down. Perhaps, what's needed here is a more dynamic model of evolutionary change linking hypotheses of synapomorphy with specific changes in the structuring “rules” (or capacities) of development.Among characters used to diagnose major groups of vascular plants, differences in stelar architecture remain among the most important. Comparative evidence suggests that early vascular plants have essentially the same relatively well-understood developmental mechanisms as living plants; vascular tissues differentiate according to hormone (primarily auxin) gradient signals, that are the more-or-less the passive consequence of shoot geometry during growth. Because early plants have an extremely simple organography (dichotomizing stems with no leaves), an unparalleled opportunity exists to understand historical changes leading to establishment of major stelar morphs in the fossil record terms of changed dynamics of continuous serial development at the shoot apex. A computer simulation of vascular tissue patterning under hormone influence will be presented, and suggestions offered regarding the relative plausibility of alternate routes of evolutionary change between major groups.

Fossil evidence for plant-arthropod interactions in the Palaeozoic and Mesozoic

1991 ◽  
Vol 333 (1267) ◽  
pp. 177-186 ◽  
Keyword(s):  
Fossil Record ◽  
Vascular Plants ◽  
Feeding Activity ◽  
Late Carboniferous ◽  
Gut Contents ◽  
Leaf Miners ◽  
Plant Feeding ◽  
Plant Animal Interactions ◽  
Wood Boring

Some of the earliest Devonian fossils of vascular plants show lesions that may be attributed to plant feeding activity by animals. This is the beginning of a more or less continuous fossil record of plant-animal interactions which extends from the Devonian to the present day. An important feature of pre-Cretaceous material is the evidence from coprolites and gut-contents of spore eating by arthropods. Experiments with living arthropods, of groups represented in the Palaeozoic, show that viable spores can survive passage through the gut in significant numbers. Spore eating could clearly have had a dispersal role of value to the plant, as well as its evident benefit as a source of nutrition for the animal involved. Evidence of wood boring and leaf eating extends from the late Carboniferous onwards. It appears that ‘continuous marginal’ leaf-feeding preceded 'interrupted marginal’ feeding, and that this was in turn followed by ‘non-marginal’ leaf feeding. The latter first appeared in Cretaceous angiosperms. Some diversity of leaf miners and leaf galls are also represented in Cretaceous angiosperm leaf fossils.

The evolution and biological significance of seeds

1983 ◽  
Vol 61 (12) ◽  
pp. 3550-3560 ◽  
Author(s):  
T. A. Steeves
Keyword(s):  
Adaptive Radiation ◽  
Fossil Record ◽  
Vascular Plants ◽  
Biological Significance ◽  
Free Water ◽  
Significant Component ◽  
Early Mesozoic ◽  
Evolutionary Event ◽  
Fossil Floras ◽  
The Relationship

No evolutionary event in the colonization of the land by vascular plants is of greater significance than the appearance of the seed habit. What apparently began as an adaptation enhancing sexual reproduction in the absence of external free water has assumed a far broader importance in terms of survival and dispersal. The essential features of the seed habit are identified in relation to heterospory, megaspore retention, and endosporic gametophyte development and approaches to the seed habit by nonseed plants are reviewed. Seeds first appear in the fossil record of the Late Devonian Period and, in diverse forms and sizes, constitute a significant component of Carboniferous fossil floras. The rise to dominance of plants of gymnospermous affinity in the early Mesozoic and the appearance and rapid adaptive radiation of the angiosperms are discussed in relation to the significance of the seed habit. The structure and development of modern gymnosperm and angiosperm seeds are compared, and the contrasting patterns of embryogenesis in these two types of seeds are interpreted in terms of the relationship between the embryo and its nutritive support system.

scholarly journals The relationships of vascular plants

2000 ◽  
Vol 355 (1398) ◽  
pp. 847-855 ◽  
Author(s):  
P. Kenrick
Keyword(s):  
Life Cycle ◽  
Fossil Record ◽  
Vascular Plants ◽  
Vascular Plant ◽  
Comparative Morphology ◽  
Life Cycles ◽  
Plant Evolution ◽  
Seed Plants ◽  
Geological Conditions ◽  
Life Cycle Evolution

Recent phylogenetic research indicates that vascular plants evolved from bryophyte–like ancestors and that this involved extensive modifications to the life cycle. These conclusions are supported by a range of systematic data, including gene sequences, as well as evidence from comparative morphology and the fossil record. Within vascular plants, there is compelling evidence for two major clades, which have been termed lycophytes (clubmosses) and euphyllophytes (seed plants, ferns, horsetails). The implications of recent phylogenetic work are discussed with reference to life cycle evolution and the interpretation of stratigraphic inconsistencies in the early fossil record of land plants. Life cycles are shown to have passed through an isomorphic phase in the early stages of vascular plant evolution. Thus, the gametophyte generation of all living vascular plants is the product of massive morphological reduction. Phylogenetic research corroborates earlier suggestions of a major representational bias in the early fossil record. Megafossils document a sequence of appearance of groups that is at odds with that predicted by cladogram topology. It is argued here that the pattern of appearance and diversification of plant megafossils owes more to changing geological conditions than to rapid biological diversification.

Diversification dynamics of cheilostome bryozoans based on a Bayesian analysis of the fossil record

Palaeontology ◽  
2022 ◽  
Author(s):  
Farideh Moharrek ◽  
Paul D. Taylor ◽  
Daniele Silvestro ◽  
Helen L. Jenkins ◽  
Dennis P. Gordon ◽  
...  
Keyword(s):  
Bayesian Analysis ◽  
Fossil Record ◽  
Cheilostome Bryozoans

scholarly journals The Past Sure Is Tense: On Interpreting Phylogenetic Divergence Time Estimates

2017 ◽  
Author(s):  
Joseph W. Brown ◽  
Stephen A. Smith
Keyword(s):  
Bayesian Analysis ◽  
Early Cretaceous ◽  
Fossil Record ◽  
Divergence Time ◽  
Time Estimation ◽  
Inference Problem ◽  
Divergence Time Estimation ◽  
Divergence Time Estimates ◽  
The Impact ◽  
Pseudo Data

AbstractDivergence time estimation — the calibration of a phylogeny to geological time — is an integral first step in modelling the tempo of biological evolution (traits and lineages). However, despite increasingly sophisticated methods to infer divergence times from molecular genetic sequences, the estimated age of many nodes across the tree of life contrast significantly and consistently with timeframes conveyed by the fossil record. This is perhaps best exemplified by crown angiosperms, where molecular clock (Triassic) estimates predate the oldest (Early Cretaceous) undisputed angiosperm fossils by tens of millions of years or more. While the incompleteness of the fossil record is a common concern, issues of data limitation and model inadequacy are viable (if underexplored) alternative explanations. In this vein, Beaulieu et al. (2015) convincingly demonstrated how methods of divergence time inference can be misled by both (i) extreme state-dependent molecular substitution rate heterogeneity and (ii) biased sampling of representative major lineages. These results demonstrate the impact of (potentially common) model violations. Here, we suggest another potential challenge: that the configuration of the statistical inference problem (i.e., the parameters, their relationships, and associated priors) alone may preclude the reconstruction of the paleontological timeframe for the crown age of angiosperms. We demonstrate, through sampling from the joint prior (formed by combining the tree (diversification) prior with the calibration densities specified for fossil-calibrated nodes) that with no data present at all, that, an Early Cretaceous crown angiosperms is rejected (i.e., has essentially zero probability). More worrisome, however, is that, for the 24 nodes calibrated by fossils, almost all have indistinguishable marginal prior and posterior age distributions when employing routine lognormal fossil calibration priors. These results indicate that there is inadequate information in the data to overrule the joint prior. Given that these calibrated nodes are strategically placed in disparate regions of the tree, they act to anchor the tree scaffold, and so the posterior inference for the tree as a whole is largely determined by the pseudo-data present in the (often arbitrary) calibration densities. We recommend, as for any Bayesian analysis, that marginal prior and posterior distributions be carefully compared to determine whether signal is coming from the data or prior belief, especially for parameters of direct interest. This recommendation is not novel. However, given how rarely such checks are carried out in evolutionary biology, it bears repeating. Our results demonstrate the fundamental importance of prior/posterior comparisons in any Bayesian analysis, and we hope that they further encourage both researchers and journals to consistently adopt, this crucial step as standard practice. Finally, we note that the results presented here do not refute the biological modelling concerns identified by Beaulieu et al. (2015). Both sets of issues remain apposite to the goals of accurate divergence time estimation, and only by considering them in tandem can we move forward more confidently. [marginal priors; information content; diptych; divergence time estimation; fossil record; BEAST; angiosperms.]

Sign in / Sign up

Export Citation Format

Share Document