Integrating morphology and phylogenomics supports a terrestrial origin of insect flight
2019; National Academy of Sciences; Volume: 116; Issue: 8 Linguagem: Inglês
10.1073/pnas.1822087116
ISSN1091-6490
Autores Tópico(s)Insect and Arachnid Ecology and Behavior
Resumo> I picture a small aquatic insect…which would thus learn to fly while passively air-borne; not, of course, by studying aerodynamics, but by trial and error. > > —Sir Vincent Wigglesworth Of all of the extant groups in the animal Tree of Life, the staggering diversity of insects makes the resolution of their phylogenetic relationships a herculean task. The phylogeny of insects is the fulcrum that underlies various macroevolutionary phenomena, such as the evolution of winged flight, parental care, cospeciation with plants, and morphological specializations for diverse modes of feeding, to name but a few. However, a stable insect phylogeny has historically remained elusive, even after the advent of molecular systematics nearly two decades ago (1⇓⇓–4), owing to limitations in molecular dataset size, the informativeness of available loci, and taxonomic sampling. In PNAS, Wipfler et al. (5) bring to bear a dataset of over 3,000 genes and over 100 taxa to resolve the relationships of Polyneoptera, a subdivision of insects that includes such groups as cockroaches, termites, crickets, walking sticks, and praying mantises. Using this phylogenetic framework, they inferred the ancestral states of various morphological and life history traits and came to an unexpected conclusion: The ancestor of winged insects did not have an aquatic nymph (Fig. 1). Fig. 1. ( Left ) Traditional phylogeny of insects reflecting the uncertain placement of key groups with aquatic larvae (blue) and inferred ancestral state in the common ancestor of Pterygota (the winged insects). Tree topology integrates over a number of historical phylogenies, based on morphological data and/or Sanger-sequenced loci. ( Right ) Phylogenomic tree of a resolved Polyneoptera (red) from the supermatrix analyses of Wipfler et al. (5), reflecting the ancestral state reconstruction of an aquatic larval stage. Some background is required to put this inference and its implications into context. The monophyly of Pterygota (the … [↵][1]1Email: prashant.sharma{at}wisc.edu. [1]: #xref-corresp-1-1
Referência(s)