@article {267,
	title = {Phylogenetic signal and its decay in mitochondrial SSU and LSU rRNA gene fragments of Anisoptera},
	journal = {Mol Biol Evol},
	volume = {18},
	number = {1},
	year = {2001},
	month = {Jan},
	pages = {27-37},
	abstract = {The phylogeny of Anisoptera, dragonflies in the strict sense, has proven to be notoriously difficult to resolve. Based on morphological characters, several recent publications dealing with the phylogeny of dragonflies proposed contradicting inter- and intrafamily relationships. We explored phylogenetic information content of mitochondrial large-subunit (LSU) and small-subunit (SSU) ribosomal gene fragments for these systematic problems. Starting at published universal primers, we developed primer sets suitable for amplifying large parts of the LSU and SSU rRNA genes within dragonflies. These fragments turned out to harbor sufficient phylogenetic information to satisfyingly resolve intrafamily relationships, but they contain insufficient phylogenetic structure to permit reliable conclusions about several interfamily relationships. We demonstrate that decay of phylogenetic signal progresses from intrafamily to interfamily to outgroup relationships and is correlated with an increase of genetic distances. As expected, signal decay is most pronounced in fast-changing sites. Additionally, base composition among fast-changing sites significantly deviates from the expected homogeneity. Homogeneity of base composition among all included taxa was restored only after removing fast-changing sites from the data set. The molecular data tentatively support interfamily relationships proposed by the most recent publication based on morphological characters of fossil and extant dragonflies.},
	author = {Misof, B and Rickert, A M and Buckley, T R and Fleck, G and Sauer, K P}
}
@article {208,
	title = {A phylogenomic approach to resolve the basal pterygote divergence},
	journal = {Mol Biol Evol},
	year = {2009},
	month = {Aug},
	abstract = {One of the most fascinating Bauplan transitions in the animal kingdom was the invention of insect wings, a change which also contributed to the success and enormous diversity of this animal group. However, the origin of insect flight and the relationships of basal winged insect orders are still controversial. Three hypotheses have been proposed to explain the phylogeny of winged insects: (i) the traditional Palaeoptera hypothesis (Ephemeroptera+Odonata, Neoptera), (ii) the Metapterygota (Ephemeroptera, Odonata+Neoptera) and (iii) the Chiastomyaria hypothesis (Odonata, Ephemeroptera+Neoptera). Neither phylogenetic analyses of single genes nor even multiple marker systems (e.g. molecular markers + morphological characters) have yet been able to conclusively resolve basal pterygote divergences. A possible explanation for the lack of resolution is that the divergences took place in the mid-Devonian within a short period of time, and attempts to solve this problem have been confounded by the major challenge of finding molecular markers to accurately track these short ancient internodes. Although phylogenomic data are available for Neoptera and some wingless (apterygote) orders, they are lacking for the crucial Odonata and Ephemeroptera orders. We adopt a multi-gene approach including data from two new EST projects - from the orders Ephemeroptera (Baetis sp.) and Odonata (Ischnura elegans) - to evaluate the potential of phylogenomic analyses in clarifying this unresolved issue. We analyzed two data sets that differed in represented taxa, genes and overall sequence lengths: maxspe (15 taxa, 125 genes, 31,643 amino acid positions), maxgen (8 taxa, 150 genes, 42,541 amino acid positions). Maximum likelihood and Bayesian inference analyses both place the Odonata at the base of the winged insects. Furthermore, statistical hypotheses testing rejected both the Palaeoptera and the Metapterygota hypotheses. The comprehensive molecular data set developed here provides conclusive support for odonates as the most basal winged insect order (Chiastomyaria hypothesis). Data quality assessment indicates that proteins involved in cellular processes and signaling harbor the most informative phylogenetic signal.},
	author = {Simon, Sabrina and Strauss, Sascha and von Haeseler, Arndt and Hadrys, Heike}
}
