Mayhew, P J (2002) Shifts in hexapod diversification and what Haldane could have said. Proceedings of the Royal Society B: Biological Sciences. pp. 969-974. ISSN 1471-2954Full text available as:
Data on species richness and taxon age are assembled for the extant hexapod orders (insects and their six-legged relatives). Coupled with estimates of phylogenetic relatedness, and simple statistical null models, these data are used to locate where, on the hexapod tree, significant changes in the rate of cladogenesis (speciation-minus-extinction rate) have occurred. Significant differences are found between many successive pairs of sister taxa near the base of the hexapod tree, all of which are attributable to a shift in diversification rate after the origin of the Neoptera (insects with wing flexion) and before the origin of the Holometabola (insects with complete metamorphosis). No other shifts are identifiable amongst supraordinal taxa. Whilst the Coleoptera have probably diversified faster than either of their putative sister lineages, they do not stand out relative to other closely related clades. These results suggest that any Creator had a fondness for a much more inclusive clade than the Coleoptera, definitely as large as the Eumetabola (Holometabola plus bugs and their relatives), and possibly as large as the entire Neoptera. Simultaneous, hence probable causative events are discussed, of which the origin of wing flexion has been the focus of much attention.
|Copyright, Publisher and Additional Information:||© 2002 The Royal Society|
|Keywords:||adaptive radiation, extinction, Insecta, macroevolution, speciation, tree balance, EVOLUTIONARY PROCESS, INSECTS, PHYLOGENY, ARCHITECTURE, SPECIATION|
|Academic Units:||The University of York > Biology (York)|
|Depositing User:||Repository Officer|
|Date Deposited:||13 Jun 2006|
|Last Modified:||17 Oct 2013 14:32|