Limits...
Molecular phylogeny of the Drosophila obscura species group, with emphasis on the Old World species.

Gao JJ, Watabe HA, Aotsuka T, Pang JF, Zhang YP - BMC Evol. Biol. (2007)

Bottom Line: The subobscura and microlabis subgroups form the basal clade in this group.The obscura subgroup is paraphyletic.Partial members of this subgroup (D. ambigua, D. obscura, D. tristis, D. subsilvestris, and D. dianensis) form a monophyletic group which appears to be most closely related to the sinobscura subgroup.

View Article: PubMed Central - HTML - PubMed

Affiliation: Laboratory for Conservation and Utilization of Bio-resources, Yunnan University, Kunming, Yunnan, China. gao-leyun@263.net <gao-leyun@263.net>

ABSTRACT

Background: Species of the Drosophila obscura species group (e.g., D. pseudoobscura, D. subobscura) have served as favorable models in evolutionary studies since the 1930's. Despite numbers of studies conducted with varied types of data, the basal phylogeny in this group is still controversial, presumably owing to not only the hypothetical 'rapid radiation' history of this group, but also limited taxon sampling from the Old World (esp. the Oriental and Afrotropical regions). Here we reconstruct the phylogeny of this group by using sequence data from 6 loci of 21 species (including 16 Old World ones) covering all the 6 subgroups of this group, estimate the divergence times among lineages, and statistically test the 'rapid radiation' hypothesis.

Results: Phylogenetic analyses indicate that each of the subobscura, sinobscura, affinis, and pseudoobscura subgroups is monophyletic. The subobscura and microlabis subgroups form the basal clade in the obscura group. Partial species of the obscura subgroup (the D. ambigua/D. obscura/D. tristis triad plus the D. subsilvestris/D. dianensis pair) forms a monophyletic group which appears to be most closely related to the sinobscura subgroup. The remaining basal relationships in the obscura group are not resolved by the present study. Divergence times on a ML tree based on mtDNA data are estimated with a calibration of 30-35 Mya for the divergence between the obscura and melanogaster groups. The result suggests that at least half of the current major lineages of the obscura group originated by the mid-Miocene time (~15 Mya), a time of the last developing and fragmentation of the temperate forest in North Hemisphere.

Conclusion: The obscura group began to diversify rapidly before invading into the New World. The subobscura and microlabis subgroups form the basal clade in this group. The obscura subgroup is paraphyletic. Partial members of this subgroup (D. ambigua, D. obscura, D. tristis, D. subsilvestris, and D. dianensis) form a monophyletic group which appears to be most closely related to the sinobscura subgroup.

Show MeSH

Related in: MedlinePlus

Phylogenetic trees based on AA data set. (A) Strict consensus of 17 equally parsimonious trees (tree length = 433, CI = 0.7367, RI = 0.7355); (B) Bayesian tree inferred with the Poisson model, with gamma-distributed rate variation across sites and a proportion of invariable sites; (C) Bayesian tree inferred with the GTR model, with gamma-distributed rate variation across sites and a proportion of invariable sites. Numbers besides nodes are bootstrap values of 1000 replicates in (A); those in (B) and (C) are posterior probabilities. Symbols are same as in Figure 2.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC1904182&req=5

Figure 3: Phylogenetic trees based on AA data set. (A) Strict consensus of 17 equally parsimonious trees (tree length = 433, CI = 0.7367, RI = 0.7355); (B) Bayesian tree inferred with the Poisson model, with gamma-distributed rate variation across sites and a proportion of invariable sites; (C) Bayesian tree inferred with the GTR model, with gamma-distributed rate variation across sites and a proportion of invariable sites. Numbers besides nodes are bootstrap values of 1000 replicates in (A); those in (B) and (C) are posterior probabilities. Symbols are same as in Figure 2.

Mentions: Figure 3 shows the results of phylogenetic analyses with AA data, including the strict consensus of 17 equally parsimonious MP trees (Figure 3A) and the Bayesian trees inferred with the Poisson model (Figure 3B) or the GTR (General time reversible) model (Figure 3C). All these trees recover the same set of major lineages as those trees of NT data, clearly indicating that the microlabis and subobscura subgroups are basal to the remainder ingroup species (BP = 53; PP = 0.96–0.99), all of which form a very large monophyletic group. The Bayesian analyses strongly indicate that D. microlabis forms a monophyletic group with the subobscura subgroup (PP = 0.99). All the analyses with AA data lend strong support to the monophyly of the obscura cluster (BP = 87; PP = 1.00), while the obscura-sinobscura cluster is only weakly suggested by the Bayesian tree inferred with the Poisson model.


Molecular phylogeny of the Drosophila obscura species group, with emphasis on the Old World species.

Gao JJ, Watabe HA, Aotsuka T, Pang JF, Zhang YP - BMC Evol. Biol. (2007)

Phylogenetic trees based on AA data set. (A) Strict consensus of 17 equally parsimonious trees (tree length = 433, CI = 0.7367, RI = 0.7355); (B) Bayesian tree inferred with the Poisson model, with gamma-distributed rate variation across sites and a proportion of invariable sites; (C) Bayesian tree inferred with the GTR model, with gamma-distributed rate variation across sites and a proportion of invariable sites. Numbers besides nodes are bootstrap values of 1000 replicates in (A); those in (B) and (C) are posterior probabilities. Symbols are same as in Figure 2.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC1904182&req=5

Figure 3: Phylogenetic trees based on AA data set. (A) Strict consensus of 17 equally parsimonious trees (tree length = 433, CI = 0.7367, RI = 0.7355); (B) Bayesian tree inferred with the Poisson model, with gamma-distributed rate variation across sites and a proportion of invariable sites; (C) Bayesian tree inferred with the GTR model, with gamma-distributed rate variation across sites and a proportion of invariable sites. Numbers besides nodes are bootstrap values of 1000 replicates in (A); those in (B) and (C) are posterior probabilities. Symbols are same as in Figure 2.
Mentions: Figure 3 shows the results of phylogenetic analyses with AA data, including the strict consensus of 17 equally parsimonious MP trees (Figure 3A) and the Bayesian trees inferred with the Poisson model (Figure 3B) or the GTR (General time reversible) model (Figure 3C). All these trees recover the same set of major lineages as those trees of NT data, clearly indicating that the microlabis and subobscura subgroups are basal to the remainder ingroup species (BP = 53; PP = 0.96–0.99), all of which form a very large monophyletic group. The Bayesian analyses strongly indicate that D. microlabis forms a monophyletic group with the subobscura subgroup (PP = 0.99). All the analyses with AA data lend strong support to the monophyly of the obscura cluster (BP = 87; PP = 1.00), while the obscura-sinobscura cluster is only weakly suggested by the Bayesian tree inferred with the Poisson model.

Bottom Line: The subobscura and microlabis subgroups form the basal clade in this group.The obscura subgroup is paraphyletic.Partial members of this subgroup (D. ambigua, D. obscura, D. tristis, D. subsilvestris, and D. dianensis) form a monophyletic group which appears to be most closely related to the sinobscura subgroup.

View Article: PubMed Central - HTML - PubMed

Affiliation: Laboratory for Conservation and Utilization of Bio-resources, Yunnan University, Kunming, Yunnan, China. gao-leyun@263.net <gao-leyun@263.net>

ABSTRACT

Background: Species of the Drosophila obscura species group (e.g., D. pseudoobscura, D. subobscura) have served as favorable models in evolutionary studies since the 1930's. Despite numbers of studies conducted with varied types of data, the basal phylogeny in this group is still controversial, presumably owing to not only the hypothetical 'rapid radiation' history of this group, but also limited taxon sampling from the Old World (esp. the Oriental and Afrotropical regions). Here we reconstruct the phylogeny of this group by using sequence data from 6 loci of 21 species (including 16 Old World ones) covering all the 6 subgroups of this group, estimate the divergence times among lineages, and statistically test the 'rapid radiation' hypothesis.

Results: Phylogenetic analyses indicate that each of the subobscura, sinobscura, affinis, and pseudoobscura subgroups is monophyletic. The subobscura and microlabis subgroups form the basal clade in the obscura group. Partial species of the obscura subgroup (the D. ambigua/D. obscura/D. tristis triad plus the D. subsilvestris/D. dianensis pair) forms a monophyletic group which appears to be most closely related to the sinobscura subgroup. The remaining basal relationships in the obscura group are not resolved by the present study. Divergence times on a ML tree based on mtDNA data are estimated with a calibration of 30-35 Mya for the divergence between the obscura and melanogaster groups. The result suggests that at least half of the current major lineages of the obscura group originated by the mid-Miocene time (~15 Mya), a time of the last developing and fragmentation of the temperate forest in North Hemisphere.

Conclusion: The obscura group began to diversify rapidly before invading into the New World. The subobscura and microlabis subgroups form the basal clade in this group. The obscura subgroup is paraphyletic. Partial members of this subgroup (D. ambigua, D. obscura, D. tristis, D. subsilvestris, and D. dianensis) form a monophyletic group which appears to be most closely related to the sinobscura subgroup.

Show MeSH
Related in: MedlinePlus