Phylogenomics resolves the timing and pattern of insect evolution

Abstract

Insects are the most speciose group of animals, but the phylogenetic relationships of many major lineages remain unresolved. We inferred the phylogeny of insects from 1478 protein-coding genes. Phylogenomic analyses of nucleotide and amino acid sequences, with site-specific nucleotide or domain-specific amino acid substitution models, produced statistically robust and congruent results resolving previously controversial phylogenetic relations hips. We dated the origin of insects to the Early Ordovician [~479 million years ago (Ma)], of insect flight to the Early Devonian (~406 Ma), of major extant lineages to the Mississippian (~345 Ma), and the major diversification of holometabolous insects to the Early Cretaceous. Our phylogenomic study provides a comprehensive reliable scaffold for future comparative analyses of evolutionary innovations among insects.

Absence of positive selection on CenH3 inLuzulasuggests that holokinetic chromosomes may suppress centromere drive

“…To become lost, CenH3 must first escape from natural selection. The absence of positive selection in Luzula and a high average x ¼ 0Á485 compared with other eukaryotic lineages ) might indeed suggest a relaxed selection possibly indicating an initial phase of such a process in a clade much younger than holokinetic clades of insects; the holokinetic plant family Juncaceae originated roughly 90 million years ago (Escudero et al, 2012), while Phtiraphtera, the youngest holokinetic order of insects, originated about 110 million years ago (Misof et al, 2014). Of course, CenH3 from more holokinetic clades has to be analysed to confirm or disprove that this process is really associated with the evolution of holokinetism.…”

Arthropod communities on hybrid and parental cottonwoods are phylogenetically structured by tree type: Implications for conservation of biodiversity in plant hybrid zones

“…Misof et al. (2014) also provided strong support for relationships within (e.g., basal Hymenoptera within Holometabola) and among these clades (e.g., Condylognatha + Holometabola). Overall, 79 of 198 possible phylogenetic relationships were resolved.…”

“…(2014) and additional well‐supported analyses. Each phylogenetic relationship is accompanied by a numbered node that corresponds to sources summarized in Appendix S1 …”

Structural mouthpart interaction evolved already in the earliest lineages of insects

“…Currently available morphological [9,33] and molecular evidence [11] strongly suggests that Collembola and Diplura do not form a monophyletic group. Instead Diplura are the sistergroup to ectognathous insects (bristletails, silverfish and winged insects) and Collembola the sistergroup to Protura (Ellipura hypothesis; figure 2).…”

“…Small blended food particles also are milled between the mandibles in many Collembola, while some species of Diplura prey on other soil organisms with their knife-like mandibles after hauling them towards the oral opening with their maxillae [4]. A growing body of morphological [8][9][10] and transcriptome-based studies [11] supports a sistergroup relationship of the entognathous Diplura with ectognathous insects (Cercophora hypothesis), while Protura þ Collembola (¼Ellipura) are the sistergroup to Cercophora.…”