The Origin(s) of Modern Amphibians: A Commentary

Marjanović, David; Laurin, Michel

doi:10.1007/s11692-009-9065-8

Cited by 36 publications

(62 citation statements)

References 15 publications

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“…, 2008; Marjanović & Laurin, 2009), but all studies indicate that these ‘lepospondyls’ are closely related to amniotes; thus, they are highly relevant to this study. A review of the evidence (Marjanović & Laurin, 2009) suggests that Brachydectes is the Paleozoic sister group of lissamphibians, but this pattern of relationships has yet to gain wide acceptance. We also sampled several early members of the main clades of Paleozoic amniotes.…”

Section: Methodsmentioning

confidence: 88%

Paleogenomic data suggest mammal‐like genome size in the ancestral amniote and derived large genome size in amphibians

Organ¹,

Canoville²,

Reisz³

et al. 2010

J of Evolutionary Biology

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An unsolved question in evolutionary genomics is whether amniote genomes have been expanding or contracting since the common ancestor of this diverse group. Here, we report on the polarity of amniote genome size evolution using genome size estimates for 14 extinct tetrapod genera from the Paleozoic and early Mesozoic Eras using osteocyte lacunae size as a correlate. We find substantial support for a phylogenetically controlled regression model relating genome size to osteocyte lacunae size (P of slopes < 0.01, r2 = 0.65, phylogenetic signal (λ) = 0.83). Genome size appears to have been homogeneous across Paleozoic crown‐tetrapod lineages (average haploid genome size 2.9–3.7 pg) with values similar to those of extant mammals. The differentiation in genome size and underlying architecture among extant tetrapod lineages likely evolved in the Mesozoic and Cenozoic Eras, with expansion in amphibians, contractions along the diapsid lineage, and no directional change within the synapsid lineage leading to mammals.

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Section: Methodsmentioning

confidence: 88%

Paleogenomic data suggest mammal‐like genome size in the ancestral amniote and derived large genome size in amphibians

Organ¹,

Canoville²,

Reisz³

et al. 2010

J of Evolutionary Biology

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show abstract

“…There is at present no consensus as to the evolutionary origins of the extant amphibian groups (e.g. Anderson, 2008; Marjanovic & Laurin, 2008, 2009). Modern amphibians, which are united in the taxon Lissamphibia in two out of three current hypotheses, consist of Salientia (frogs and their fossil relatives), Caudata (salamanders and newts), and Gymnophiona (caecilians), with Anura, Urodela, and Apoda constituting their respective crown groups (Milner, 1988; Cannatella & Hillis, 2004).…”

Section: Introductionmentioning

confidence: 99%

The origin of modern amphibians: a re-evaluation

Sigurdsen

Green

2011

Zoological Journal of the Linnean Society

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There are currently three competing hypotheses seeking to explain the evolutionary origins of modern amphibians. The lepospondyl hypothesis holds that the lysorophian lepospondyls constitute the sister taxon to all lissamphibians. The temnospondyl hypothesis suggests that modern amphibians are most closely related to the dissorophoid temnospondyls. Finally, the polyphyletic hypothesis posits that the modern amphibian orders have separate evolutionary origins from among different groups of Palaeozoic tetrapods. Here, we review the character matrices used in previous studies. These data sets differ significantly in choice of characters. Therefore, we built a matrix based on data from all three hypotheses and analysed key taxa phylogenetically using both Bayesian inference and parsimony. Uncorrected, the supermatrix yielded inconclusive results, demonstrating the presence of at least two phylogenetic optima. When the data were corrected according to new observations on Doleserpeton, Eocaecilia, and other fossil forms, the phylogeny supported the temnospondyl hypothesis of lissamphibian origins. This conclusion is also supported by a careful study of character changes in the individual lineages.

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“…Homoplasy generated by interpretative errors and all types of human errors may be crucial in phylogenetic reconstructions given that such errors may not be uncommon in empirical datasets (e.g. Marjanovic and Laurin 2008Laurin , 2009). The comparison of phylogenetic methods should address their robustness to such errors in the data.…”

Section: Resultsmentioning

confidence: 99%

Impact of errors on cladistic inference: simulation-based comparison between parsimony and three-taxon analysis

Rineau

Bagils

Laurin

2018

CTOZ

Self Cite

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Simulation-based and experimental studies are crucial to produce factual arguments to solve theoretical and methodological debates in phylogenetics. However, despite the large number of works that tested the relative efficiency of phylogenetic methods with various evolutionary models, the capacity of methods to manage various sources of error and homoplasy has almost never been studied. By applying ordered and unordered methods to datasets with iterative addition of errors in the ordering scheme, we show that unordered coding in parsimony is not a more cautious option. A second debate concerns how to handle reversals, especially when they are regarded as possible synapomorphies. By comparing analyses of reversible and irreversible characters, we show empirically that three-taxon analysis (3ta) manages reversals better than parsimony. For Brownian motion data, we highlight that 3ta is also more efficient than parsimony in managing random errors, which might result from taphonomic problems or any homoplasy generating events that do not follow the dichotomy reversal/ convergence, such as lateral gene transfer. We show parsimony to be more efficient with numerous character states (more than four), and 3ta to be more efficient with binary characters, both methods being equally efficient with four states per character. We finally compare methods using two empirical cases of known evolution.

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The Origin(s) of Modern Amphibians: A Commentary

Cited by 36 publications

References 15 publications

Paleogenomic data suggest mammal‐like genome size in the ancestral amniote and derived large genome size in amphibians

Paleogenomic data suggest mammal‐like genome size in the ancestral amniote and derived large genome size in amphibians

The origin of modern amphibians: a re-evaluation

Impact of errors on cladistic inference: simulation-based comparison between parsimony and three-taxon analysis

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