Evolutionary relationships among the Scarabaeini (Coleoptera: Scarabaeidae) based on combined molecular and morphological data

• Published in: Molecular phylogenetics and evolution Vol. 40; no. 3; pp. 662 - 678
• Main Authors: Forgie, Shaun A., Kryger, Ute, Bloomer, Paulette, Scholtz, Clarke H.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-09-2006
• Subjects: 16S; Animals; Base Sequence; COI; Coleoptera; Coleoptera - anatomy & histology; Coleoptera - classification; Coleoptera - genetics; Combined analysis; DNA, Mitochondrial - analysis; Dung beetle; Eucraniini; Evolution; Evolution, Molecular; Genetic Linkage; Genetic Variation; Molecular Sequence Data; Morphology; Phylogeny; RNA, Ribosomal, 16S - analysis; Scarabaeus; Sequence Homology, Nucleic Acid; Dung beetle; Combined analysis; Morphology; Evolution; Phylogeny; COI; 16S
• ISSN: 1055-7903; 1095-9513
• DOI: 10.1016/j.ympev.2006.04.018

The Scarabaeini is an old world tribe of ball-rolling dung beetles that have origins dating back to at least the mid-upper Miocene (19–8 million years ago). The tribe has received little to no attention in morphological or molecular phylogenetics. We obtained sequence data from the mitochondrial cytochrome oxidase subunit I (1197
bp) and 16S ribosomal RNA (461
bp) genes for 25 species of the Scarabaeini in an attempt to further resolve broad phylogenetic relationships within this tribe. Sequence data from both markers along with 216 morphological and 3 biological characters were analysed separately and combined. Independent analyses showed poorly resolved trees with many of the intermediate and basal nodes collapsed by low bootstrap values. Many sites in both genes exhibited strong A
+
T nucleotide bias and high interlineage divergences. The combined analysis revealed a number of well supported relationships such as the monophyly of the nocturnal species
Scarabaeus satyrus,
S. [
Neateuchus]
proboscideus, and
S. zambesianus. Furthermore, the total evidence tree suggested to elevate
S. (
Pachysoma) to the status of an independent genus,
Pachysoma, as a sister taxon to a clade containing
Pachylomerus femoralis and
Scarabaeus sensu lato. Within the latter, the following subgenera were maintained by the combination of data sets:
S. (
Scarabaeolus),
S. (
Sceliages), and
S. (
Kheper). Both, feeding specialisation and food relocation behaviour, were inferred to be polyphyletic in the Scarabaeini. Total evidence analysis found no support for common ancestry of Scarabaeini and Eucraniini.