Life-history specialization was not an evolutionary dead-end in Pyrenean cave beetles

Alternative Title

Proceedings of the Royal Society B

Link to Full Text

Download Full Text

Publication Date

4-22-2014

Volume Number

281

Issue Number

1781

Abstract

Research on subterranean organisms has focused on the colonization process and some of the associated phenotypic changes, but little is known on the long-term evolutionary dynamics of subterranean lineages and the origin of some highly specialized complex characters. One of the most extreme modifications is the reduction of the number of larval instars in some Leptodirini beetles from the ancestral 3 to 2 and ultimately a single instar. This reduction is usually assumed to have occurred independently multiple times within the same lineage and geographical area, but its evolution has never been studied in a phylogenetic framework. Using a comprehensive molecular phylogeny, we found a low number of independent origins of the reduction in the number of instars, with a single transition, dated to the Oligocene–Miocene, from 3 to 2 and then 1 instar in the Pyrenees, the best-studied area. In the Pyrenees, the 1-instar lineage had a diversification rate (0.22 diversification events per lineage per million years) significantly higher than that of 3- or 2-instar lineages (0.10), and similar to that seen in other Coleopteran radiations. Far from being evolutionary dead-ends, ancient lineages fully adapted to subterranean life seem able to persist and diversify over long evolutionary periods.

Keywords

Larval development, Speciation, Subterranean environment, Life cycle, Diversification, Evolution

Document Type

Article

Digital Object Identifier (DOI)

https://doi.org/10.1098/rspb.2013.2978

Link to Full Text

Share

 
COinS