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Theses

Fiabilité des clades et congruence taxinomique
Application à la phylogénie des téléostéens acanthomorphes

Abstract : The goal of a phylogeny is usually to get an idea of the real relationships between living organisms. It is thus not a good idea to be satisfied with the tree obtained by a simple combined analysis of the data. Indeed, even robust clades in such a tree may not be reliable. Confidence about a phylogenetic statement can only stem from a comparison between results obtained from independent data.
This thesis begins by proposing a repetition index to measure reliability. This index takes into account the number of occurrences for a clade over a set of trees obtained from independent data, that is, data unlikely to be subject to the same reconstruction biaises. The more a clade occurs this way, the more it can be considered reliable. The index also takes into account clades that are not compatible with the clade under focus and that are also repeated. The highest the number of occurrences of a clade's contradictor, the less reliable it should be considered.
In the second part of the thesis, the repetition index is calculated from a series of analyses involving about two hundred taxa. The analyses are primarily based on four nuclear markers: Rhodopsin, MLL4, IRBP and RNF213 (the latter being used for the first time). These markers are analysed under probabilistic models, separately and in combinations of 2, 3 or 4. This allows to take advantage of combined analysis while still being able to compare sets of independent results.
The results are then summarized into trees including mostly reliable clades. Several ways of dealing with the differences between the taxonomic samplings of the datasets are used.
The synthesis trees allow to refine the structure of the acantomorph (Actinopterygii: Teleostei) phylogeny. New reliable clades are identified, at several resolution levels, and new taxa are placed into the phylogeny of acanthomorph teleosts.
Complete list of metadatas

https://tel.archives-ouvertes.fr/tel-00331825
Contributor : Blaise Li <>
Submitted on : Friday, October 17, 2008 - 5:35:32 PM
Last modification on : Tuesday, September 1, 2020 - 3:16:02 PM
Long-term archiving on: : Tuesday, October 9, 2012 - 2:00:22 PM

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  • HAL Id : tel-00331825, version 1

Citation

Blaise Li. Fiabilité des clades et congruence taxinomique
Application à la phylogénie des téléostéens acanthomorphes. Autre [q-bio.OT]. Université Pierre et Marie Curie - Paris VI, 2008. Français. ⟨tel-00331825⟩

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