1.1: Molecular phylogenetics of the ant genus Camponotus

Project overview

Sub-Project progress

Challenges

Ants of the genus Camponotus occur worldwide and in very diverse habitats. This very large ant genus contains about 1000 species with a similar overall body shape. Despite their being abundant, large and obvious, the biology, ecology and taxonomy of these ants are poorly understood, which makes it a hardly manageable group. In the late 19th and early 20th century, 50 sub-genera were erected, but some may not represent natural groups and others may be as different from each other as separate genera.

Seeking solutions

We will establish whether the genus Camponotus and its sub-genera are monophyletic groups and how they relate to each other and other closely related formicine ant genera.

Approaches

We will sequence parts of 8 genes for all major sub-genera of Camponotus and 6 other ant genera. From this sequence information phylogenetic trees will be constructed using the statistical methods of Maximum Likelihood and Bayesian Inference. Using these trees we can then study the evolution of morphological and ecological characteristics of these species.

Collaboration

Ant researchers from all over the world have contributed specimens from their collections enabling us to include many groups from other continents as well as Australia. For later reference voucher specimens will be deposited in the ants section of the Australian National Insect Collection curated by Dr Steve Shattuck.

Tools for Decision Makers

We will make suggestions how to group the species of Camponotus naturally and which groups to raise to genus rank. Our results will be published in scientific journal articles. Particularly the new system of the Australian fauna will be included in the web site Australian Ants Online by Steve Shattuck and Natalie Barnett.

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Sub-Project progress

January 2010

We are establishing whether the very large ant genus, Camponotus, and its sub-genera are monophyletic groups and how they relate to each other and other closely related formicine ant genera.

With specimen sampling nearing completion and the analysis well underway, activity has shifted to exploration of the available data. Substitution models have been tested using a range of statistical methods and trees have been generated for all available taxa. These results confirm earlier findings that the genus contains various similar but unrelated species (that is, it’s polyphyletic) and that some species groups may have to be excluded from the genus.

In addition, the exploration of evolutionary pattern found in several specific character systems has begun. For example, while the metapleural gland is an autapomorphy for all ants (it is one of the characters that defines the family), this gland is absent from the majority of species of Camponotus as well as some other members of the tribe to which the genus belongs. By calibrating the trees using fossils, we will be able to provide a time frame for those significant changes in Camponotus and related formicine ants. It is important to understand the pattern of evolution in this complex and fundamental character system.

The solid phylogenetic foundation provided by this project provides the framework for a range of investigations from evolutionary studies to taxonomic revisions.

Results of this work titled, Metapleural gland evolution in formicine ants (Formicidae: Hymenoptera), were presented by Ellen Schlűns at the Darwin 200: Evolution and Biodiversity conference (Darwin, September, 2009).

 

May 2009

Sampling and sequencing work has been extended to include the majority of the Australian species (ca. 50) and species from other continents covering a range of target subgenera (ca. 50). Exploration of the data (including substitution model testing and construction of a first tree covering 12 subgenera) indicates the genus is polyphyletic and some groups may have to be excluded from the genus.

A tree covering the now sequenced species will be produced to continue the data exploration and to present the results later in the year.

 

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