Zhi-Hui Su

Phylogenetic relationships and evolution of the Japanese Carabinae ground beetles based on mitochondrial ND5 gene sequences

The phylogenetic relationships of the Japanese Carabinae ground beetles were analyzed by comparing 1,069 nucleotide sequences in the mitochondrial gene encoding NADH dehydrogenase subunit 5 (ND5). The ND5 phylogenetic tree revealed that the hind-wingless Carabina and the hind-wingedCalosoma/Campalita (Calosomina) diverged from the common ancestor, andCychrus (Cychrini) is the outgroup of them. Five distinct clusters (groups) can be recognized in the Carabina, i.e.,CARABUS, HEMICARABUS, LEPTOCARABUS, APOTOMOPTERUS, andPROCRUSTES/DAMASTER. The ancestors of these lineages diverged almost at the same time more than 10 Myr ago. TheCarabus cluster includes two subclusters,Carabus andOhomopterus. Two species ofCarabus examined are phylogenetically rather remote, while five species amongOhomopterus are closely related to each other. The results suggest that diversification ofCarabus started much earlier than that ofOhomopterus, presumably in the Eurasian continent, and that ofOhomopterus in the Japanese archipelago. The branching order in theLEPTOCARABUS lineage was established,Authenocarabus/Pentacarabus being their outgroup. In theDAMASTER/PROCRUSTES lineage,Procrustes is placed as the outgroup ofDamaster, with the branching order ofCoptolabrus andAcoptolabrus/Damaster. The diversification of theDamaster subspecies appeared to have occurred in the Japanese archipelago earlier thanOhomopterus, and its phylogeny reflects their geographic distribution in the archipelago rather than the morphological characters.

PARALLEL EVOLUTION IN RADIATION OF OHOMOPTERUS GROUND BEETLES INFERRED FROM MITOCHONDRIAL ND5 GENE SEQUENCES

Molecular phylogenetic analyses using mitochondrial NADH dehydrogenase subunit 5 (ND5) gene sequences representing all 15 species and the majority of subspecies or races of theOhomopterus ground beetles from all over the Japanese archipelago have uncovered a remarkable evolutionary history. Clustering of the species in the molecular phylogenetic tree is linked to their geographic distribution and does not correlate with morphological characters. Taxonomically the “same” species or the members belonging to the same species-group fall out in more than two different places on the ND5 tree. Evidence has been presented against a possible participation of ancestral polymorphism and random lineage sorting or of hybrid individuals for the observed distribution of mitochondrial DNA haplotypes. The most plausible explanation of our results is that parallel evolution took place in different lineages. Most notably,O. dehaanii, O. yaconinus, andO. japonicus in a lineage reveal almost identical morphology with those of the “same” species (or subspecies) but belonging to the phylogenetically remote lineages.

Evolution of the carabid ground beetles

The phylogenetic relationships of the carabid ground beetles have been estimated by analysing a large part of the ND5 gene sequences of more than 1,000 specimens consisting of the representative species and geographic races covering most of the genera and subgenera known in the world. From the phylogenetic analyses in conjunction with the mtDNA-based dating, a scenario of the establishment of the present habitats of the respective Japanese carabids has been constructed. The carabid diversification took place ca. 40 MYA as an explosive radiation of the major genera. During evolution, occasional small or single bangs also took place, sometimes accompanied by parallel morphological evolution in phylogenetically remote as well as close lineages. The existence of silent periods, in which few morphological changes took place, has been recognized during evolution. Thus, the carabid evolution is discontinuous, alternatively having a phase of rapid morphological change and a silent phase.

Formation of the Japanese Carabina fauna inferred from a phylogenetic tree of mitochondrial ND5 gene sequences (Coleoptera, Carabidae).

Abstract. Phylogenetic analyses based on the mitochondrial ND5 gene comparisons and the geohistory of the Japanese Islands suggest that each Japanese species belonging to the subtribe Carabina has its own history for the establishment of its present habitat in the Japanese Islands. It can be roughly classified into two categories: (1) species which were derived from the ancestry that inhabited ancient Japan at the time of its split from the Eurasian Continent [ca. 15 million years ago (MYA)], followed by diversification within the Japanese Islands; and (2) species which invaded Hokkaido from the Eurasian Continent through land-bridges from Sakhalin and/or the Kuriles or from western Japan from the Korean Peninsula during the glacial era (<2 MYA).

Geography-Linked Phylogeny of the Damaster Ground Beetles Inferred from Mitochondrial ND5 Gene Sequences

We have constructed phylogenetic trees based on sequence comparisons of mitochondrial NADH dehydrogenase subunit 5 gene for 11Damaster blaptoides specimens from various localities of Japan. The specimens consist of eight “subspecies.”Coptolabrus fruhstorferi, Acoptolabrus gehinii, andProcrustes kolbei, which are taxonomically related toDamaster, have also been analyzed for comparison.Damaster is more related toAcoptolabrus than toCoptolabrus in the ND5 trees, in contrast to the generally accepted view thatDamaster is derived fromCoptolabrus, whereasAcoptolabrus is the sister group ofDamaster/Coptolabrus. The emergence ofProcrustes is much earlier than the rest of the genera. TheDamaster subspecies are monophyletic. Four major lineages are recognized, which are geography linked within the Japanese archipelago. The origin and diversification process have been discussed based on these findings.

Sympatric Convergence of the Color Pattern in the Chilean Ceroglossus Ground Beetles Inferred from Sequence Comparisons of the Mitochondrial ND5 Gene

Abstract. The phylogenetic trees have been constructed using the mitochondrial ND5 gene sequences for 66 specimens of the Chilean Ceroglossus ground beetles collected from various localities of Chile. The trees show that the Ceroglossus specimens examined are composed of four phylogenetic lineages that have diverged 25–30 MYA. The results are consistent with the classification proposed by Jiroux (1996) based on morphology, in which Ceroglossus is divided into four species groups. Despite a remarkable color polymorphism revealed by these ground beetles, the color pattern is geographically linked and is not species-specific, suggesting that some ecological or environmental factors are involved in determining it.

Phylogeny and evolution of Digitulati ground beetles (Coleoptera, Carabidae) inferred from mitochondrial ND5 gene sequences

Genealogical trees have been constructed using mitochondrial ND5 gene sequences of 87 specimens consisting of 32 species which have been believed to belong to the division Digitulati (one of the lineages of the subtribe Carabina) of the world. There have been recognized six lineages, which are well separated from each other. Each lineage contains the following genus: (1) the lineage A: Ohomopterus from Japan; (2) the lineage B: Isiocarabus from eastern Eurasian Continent; (3) the lineage C: Carabus from China which are further subdivided into three sublineages; (4) the lineage D: Carabus from USA; (5) the lineage E: Carabus from the Eurasian Continent, Japan and North America; and (6) the lineage F: Eucarabus from the Eurasian Continent. Additionally, the genus Acrocarabus which had been treated as a constituent of the division Archicarabomorphi has been recognized to be the 7th lineage of the division Digitulati from the ND5 genealogical analysis as well as morphology. These lineages are assumed to have radiated within a short period and are largely linked to their geographic distribution.

Phylogeny and Distribution of the Subfamily Carabinae

The samples collected and used in this study cover almost the entire distribution range of carabid beetles (Fig. 2.1). Specimens come from more than 500 locations in about 35 countries. The samples represent more than 90% of the carabid genera and include about a half of the entire carabid species so far discovered.

Formation of the Japanese Carabina Fauna

The Japanese Carabina are currently classified into 12 genera, 36 species, and many subspecies (Imura and Mizusawa 1996) (Fig. 6.1).

Molecular Phylogeny of the Carabinae

There are now known to be about 150 species of Cychrini which are classified into four genera. All these beetles are without hind wings and have elytra fused at suture, so that they cannot fly, having undergone considerable geographically linked speciation. The range of their distribution is restricted to the Northern Hemisphere.