THE TIME OF ORIGIN OF THE FLOWERING PLANTS DETERMINED BY USING AMINO ACID SEQUENCE DATA OF CYTOCHROME <i>C</i>

Ramshaw, John A. M.; Richardson, D.; Meatyard, Barry T.; Brown, R. H.; Richardson, Michael; Thompson, E. W.; Boulter, D.

doi:10.1111/j.1469-8137.1972.tb01956.x

Cited by 56 publications

(40 citation statements)

References 24 publications

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“…Cytochrome c gives reasonably constant values for plants, insects, fish, and land vertebrates. [This isn't strictly true, although Boulter (1972) and Ramshaw et al (1972) believe it is and seriously propose a phyletic divergence within angiosperms in the middle Paleozoic. This contradicts the fossil record (e.g.…”

Section: The Red Queen's Problemsmentioning

confidence: 87%

Molecular evolution as predicted by natural selection

Valen

1974

J Mol Evol

157

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Summary. The major difficulty with selectionist explanations of molecular evolution has been their lack of a prediction of roughly constant evolutionary rates. A new selectionist theory (the Red Queen's Hypothesis), motivated by paleontology and derivable ecologically, makes such a prediction directly. Not all its other predictions are now verified. The counter-intuitive theory presupposes that an increase in momentary fitness by one species causes an equal total decline in momentary fitness among ecologically interacting species. Although some arguments for the selectionist approach seenl invalid, this general approach remains plausible.

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Section: The Red Queen's Problemsmentioning

confidence: 87%

Molecular evolution as predicted by natural selection

Valen

1974

J Mol Evol

157

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“…Some of the earliest strict clock studies (e.g., Ramshaw, 1972Martin et al, 1989Brandl et al, 1992) estimated ages of 300 Ma or older for angiosperms, or within angiosperms. Relaxed clock studies have also provided older-than-fossil estimates, for example, the most recent studies (Bell et al, 2010;Magallón, 2010;Smith et al, 2010;Clarke et al, 2011) estimate the crown age of angiosperms between 147 Ma (Bell et al, 2010) and 275 Ma (Magallón, 2010).…”

mentioning

confidence: 99%

A Review of the Effect of Relaxed Clock Method, Long Branches, Genes, and Calibrations in the Estimation of Angiosperm Age

Magallón

2014

Bot. Sci.

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Abstract:The timing of angiosperm origin and diversifi cation is crucial to understand the evolution of terrestrial ecosystems as we know them today. The fossil record and relaxed molecular clocks provide substantially different estimates of the time in which angiosperms started to diversify into lineages that originated living species. The roles of different methodological and systematic factors on ages estimated with relaxed clocks across land plants, with a focus on angiosperms, are here reviewed. Different relaxed clocks and molecular data provided similar age estimates for nodes across land plants. Breaking the long branch subtending angiosperms typically did not result in substantially younger age estimates for angiosperms. Including or excluding fossil-derived calibrations on internal nodes had a pronounced effect on ages across the tree, and among examined factors, calibrations were the most infl uential in resulting ages. However, interactions between calibrations and genes were detected as different genes converged on similar ages when the same set of calibrations was applied. Estimated angiosperm ages were much older than angiosperm earliest fossils. Although a missing fossil history cannot be ruled out, this explanation alone is insuffi cient, considering the gradually increasing abundance, diversity and geographical distribution of angiosperms in the fossil record; the ordered progression of their morphological and functional diversifi cation; and the agreement in the sequence of appearance of lineages in the stratigraphic record and in molecular phylogenies. It is hypothesized that model misspecifi cation may play a role in the observed molecular clock/fossil discrepancy. Key words: calibrations, fossil record, land plants, lineage effects, model misspecifi cation.Resumen: La edad del origen y diversifi cación de las angiospermas son cruciales para entender la evolución de los ecosistemas terrestres modernos. El registro fósil y los relojes moleculares relajados calculan edades substancialmente diferentes para el inicio de la diversifi cación de las angiospermas. Se revisa el efecto de diferentes factores metodológicos y sistemáticos en los estimados de relojes relajados para las plantas terrestres, con énfasis en las angiospermas. Diferentes métodos de reloj relajado y datos moleculares estimaron edades similares en todo el árbol fi logenético. Romper la rama larga que subyace a las angiospermas no resultó en edades substancialmente más jóvenes. La inclusión o exclusión de calibraciones derivadas del registro fósil tuvo un efecto pronunciado en las edades estimadas, además de ser el factor más relevante entre los que se evaluaron. Sin embargo, existen interacciones entre las calibraciones y los genes, pues diferentes genes convergieron en edades similares cuando las mismas calibraciones fueron aplicadas. Las edades estimadas para las angiospermas son mucho más viejas que sus primeros fósiles. Aunque la posibilidad de un registro fósil incompleto no puede excluirse, ésta sola explicación es insufi ...

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“…Molecular-based estimates of divergence times in plants reveal a vast range of dates: for example, the age of the angiosperms has been estimated as 350-420 mya (18), Ͼ319 mya (8, 9), 200 mya (19,20), 160 mya (7), to 140-190 mya (11). However, although some of these studies examined potential error caused by calibration time, lineage effects, or substitutional noise, only Sanderson and Doyle (11) thoroughly investigated multiple sources of error.…”

mentioning

confidence: 99%

Rate heterogeneity among lineages of tracheophytes: Integration of molecular and fossil data and evidence for molecular living fossils

Soltis

Savolainen

et al. 2002

Proc. Natl. Acad. Sci. U.S.A.

232

152

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Many efforts to date evolutionary divergences by using a molecular clock have yielded age estimates that are grossly inconsistent with the paleontological evidence. Such discrepancies often are attributed to the inadequacy of the fossil record, but many potential sources of error can affect molecular-based estimates. In this study, we minimize the potential error caused by inaccurate topology and uncertain calibration times by using a well-supported tree, multiple genes, and multiple well-substantiated dates to explore the correspondence between the fossil record and molecular-based age estimates for major clades of tracheophytes. Age estimates varied because of gene effects, codon position, lineage effects, method of inferring branch lengths, and whether or not rate constancy was assumed. However, even methods designed to ameliorate the effects of rate heterogeneity among lineages could not accommodate the substantially slower rates observed in Marattia ؉ Angiopteris and in the tree ferns. Both of these clades of ferns have undergone dramatic decelerations in their rates of molecular evolution and are ''molecular living fossils,'' consistent with their relative morphological stasis for the past 165-200 million years. Similar discrepancies between the fossil record and molecular-based age estimates noted in other studies may also be explained in part by violations of rate constancy among lineages.

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THE TIME OF ORIGIN OF THE FLOWERING PLANTS DETERMINED BY USING AMINO ACID SEQUENCE DATA OF CYTOCHROME C

Cited by 56 publications

References 24 publications

Molecular evolution as predicted by natural selection

Molecular evolution as predicted by natural selection

A Review of the Effect of Relaxed Clock Method, Long Branches, Genes, and Calibrations in the Estimation of Angiosperm Age

Rate heterogeneity among lineages of tracheophytes: Integration of molecular and fossil data and evidence for molecular living fossils

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