Non-adaptive change in early land plant evolution

Primary vascular architecture of members of the Paleozoic Aneurophytales (Progymnosper-mopsida) is described. This architecture is somewhat more complex but fundamentally similar (homologous) to that of members of the Trimerophytina, putative ancestors of aneurophytes. It is suggested that the presence of complex stelar morphology in aneurophytes was epiphenomenal, a passive result of changes in growth and development in a trimerophyte-like ancestor. Specifically, I suggest that the evolutionary transformation in primary vascular architecture from haplostele to ribbed protostele was a direct consequence of changes that affected the vertical spacing and degree of organization of lateral appendages in early vascular plants. This view is in sharp contrast to adaptationist explanations of change in stelar morphology expressed by other authors and provides an example of non-adaptive change in evolution.

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Modeling Optimization and Early Land Plant Evolution

Modeling Biology ◽

10.7551/mitpress/7430.003.0022 ◽

2007 ◽

Keyword(s):

Land Plant ◽

Plant Evolution ◽

Early Land Plant ◽

Land Plant Evolution ◽

Early Land

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The hornwort genome and early land plant evolution

Nature Plants ◽

10.1038/s41477-019-0588-4 ◽

2020 ◽

Vol 6 (2) ◽

pp. 107-118 ◽

Cited By ~ 31

Author(s):

Jian Zhang ◽

Xin-Xing Fu ◽

Rui-Qi Li ◽

Xiang Zhao ◽

Yang Liu ◽

...

Keyword(s):

Land Plant ◽

Plant Evolution ◽

Early Land Plant ◽

Land Plant Evolution ◽

Early Land

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

Geological Magazine ◽

10.1017/s0016756800033537 ◽

1986 ◽

Vol 123 (4) ◽

pp. 445-454 ◽

Cited By ~ 26

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.

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Diversification of fts Z During Early Land Plant Evolution

Journal of Molecular Evolution ◽

10.1007/s00239-003-2535-1 ◽

2004 ◽

Vol 58 (2) ◽

pp. 154-162 ◽

Cited By ~ 26

Author(s):

Stefan A. Rensing ◽

Justine Kiessling ◽

Ralf Reski ◽

Eva L. Decker

Keyword(s):

Land Plant ◽

Plant Evolution ◽

Early Land Plant ◽

Land Plant Evolution ◽

Early Land

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A polycomb repressive complex 2 gene regulates apogamy and gives evolutionary insights into early land plant evolution

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.0906997106 ◽

2009 ◽

Vol 106 (38) ◽

pp. 16321-16326 ◽

Cited By ~ 83

Author(s):

Y. Okano ◽

N. Aono ◽

Y. Hiwatashi ◽

T. Murata ◽

T. Nishiyama ◽

...

Keyword(s):

Land Plant ◽

Plant Evolution ◽

Polycomb Repressive Complex ◽

Polycomb Repressive Complex 2 ◽

Early Land Plant ◽

Land Plant Evolution ◽

Early Land

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The timescale of early land plant evolution

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1719588115 ◽

2018 ◽

Vol 115 (10) ◽

pp. E2274-E2283 ◽

Cited By ~ 244

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.

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