Limits...
Origin and Diversification of Dung Beetles in Madagascar.

Miraldo A, Wirta H, Hanski I - Insects (2011)

Bottom Line: We discuss the likely mechanisms of speciation and the ecological characteristics of the extant communities, emphasizing the role of adaptation along environmental gradients and allopatric speciation in generating the exceptionally high beta diversity in Malagasy dung beetles.Phylogeographic analyses of selected species reveal complex patterns with evidence for genetic introgression between old taxa.The introduction of cattle to Madagascar 1500 years ago created a new abundant resource, onto which a few species haveshifted and thereby been able to greatly expand their geographical ranges.

View Article: PubMed Central - PubMed

Affiliation: Metapopulation Research Group, Department of Biosciences, University of Helsinki, P.O. Box 65, FI-00014, Finland. andreia.miraldo@helsinki.fi.

ABSTRACT
Madagascar has a rich fauna of dung beetles (Scarabaeinae and Aphodiinae) withalmost 300 species described to date. Like most other taxa in Madagascar, dung beetles exhibit an exceptionally high level of endemism (96% of the species). Here,we review the current knowledge of the origin and diversification of Malagasy dung beetles. Based on molecular phylogenies, the extant dung beetles originate from eight colonizations, of which four have given rise to extensive radiations. These radiations have occurred in wet forests, while the few extant species in the less successfulradiations occur in open and semi-open habitats. We discuss the likely mechanisms of speciation and the ecological characteristics of the extant communities, emphasizing the role of adaptation along environmental gradients and allopatric speciation in generating the exceptionally high beta diversity in Malagasy dung beetles. Phylogeographic analyses of selected species reveal complex patterns with evidence for genetic introgression between old taxa. The introduction of cattle to Madagascar 1500 years ago created a new abundant resource, onto which a few species haveshifted and thereby been able to greatly expand their geographical ranges.

No MeSH data available.


Percentage sequence difference (uncorrected p distances) between pairs of individuals against geographical distance (in degrees, corresponding to 112 km at the equator). Upper row: cattle dung-using species Helictopleurus quadripunctatus (a), Helictopleurus marsyas (b) and Helictopleurus neoamplicollis (c). The open symbols in (b) are for pairs of individuals involving H. marsyas and H. nicollei [29]. Lower row: forest dwelling species Helictopleurus unifasciatus (d), Helictopleurus perrieri (e) and Nanos clypeatus (f; from Wirta 2008). Figure adapted from Hanski et al. [29].
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4553453&req=5

f2-insects-02-00112: Percentage sequence difference (uncorrected p distances) between pairs of individuals against geographical distance (in degrees, corresponding to 112 km at the equator). Upper row: cattle dung-using species Helictopleurus quadripunctatus (a), Helictopleurus marsyas (b) and Helictopleurus neoamplicollis (c). The open symbols in (b) are for pairs of individuals involving H. marsyas and H. nicollei [29]. Lower row: forest dwelling species Helictopleurus unifasciatus (d), Helictopleurus perrieri (e) and Nanos clypeatus (f; from Wirta 2008). Figure adapted from Hanski et al. [29].

Mentions: Apart from the complex past evolutionary processes, more contemporary ecological processes can also shape the current distribution of species' genetic diversity. A good example is the recent resource shift to cattle dung documented for four species of Helictopleurus, which has left a signature in their spatial genetic variation [29]. Detailed phylogeographic analysis indicated that the shift to cattle dung has occurred within a small geographical region in Helictopleurus neoamplicollis and H. marsyas, followed by a rapid range expansion resulting in low genetic diversity across their current ranges and no isolation-by-distance pattern (Figure 2). This pattern is in striking contrast with the marked isolation-by-distance pattern in three forest species (the lower row of panels in Figure 2). Helictopleurus quadripunctatus exhibits a somewhat intermediate pattern, possibly reflecting a more gradual shift in diet across much of its original range, allowing therefore the maintenance of higher genetic diversity across its current distribution.


Origin and Diversification of Dung Beetles in Madagascar.

Miraldo A, Wirta H, Hanski I - Insects (2011)

Percentage sequence difference (uncorrected p distances) between pairs of individuals against geographical distance (in degrees, corresponding to 112 km at the equator). Upper row: cattle dung-using species Helictopleurus quadripunctatus (a), Helictopleurus marsyas (b) and Helictopleurus neoamplicollis (c). The open symbols in (b) are for pairs of individuals involving H. marsyas and H. nicollei [29]. Lower row: forest dwelling species Helictopleurus unifasciatus (d), Helictopleurus perrieri (e) and Nanos clypeatus (f; from Wirta 2008). Figure adapted from Hanski et al. [29].
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4553453&req=5

f2-insects-02-00112: Percentage sequence difference (uncorrected p distances) between pairs of individuals against geographical distance (in degrees, corresponding to 112 km at the equator). Upper row: cattle dung-using species Helictopleurus quadripunctatus (a), Helictopleurus marsyas (b) and Helictopleurus neoamplicollis (c). The open symbols in (b) are for pairs of individuals involving H. marsyas and H. nicollei [29]. Lower row: forest dwelling species Helictopleurus unifasciatus (d), Helictopleurus perrieri (e) and Nanos clypeatus (f; from Wirta 2008). Figure adapted from Hanski et al. [29].
Mentions: Apart from the complex past evolutionary processes, more contemporary ecological processes can also shape the current distribution of species' genetic diversity. A good example is the recent resource shift to cattle dung documented for four species of Helictopleurus, which has left a signature in their spatial genetic variation [29]. Detailed phylogeographic analysis indicated that the shift to cattle dung has occurred within a small geographical region in Helictopleurus neoamplicollis and H. marsyas, followed by a rapid range expansion resulting in low genetic diversity across their current ranges and no isolation-by-distance pattern (Figure 2). This pattern is in striking contrast with the marked isolation-by-distance pattern in three forest species (the lower row of panels in Figure 2). Helictopleurus quadripunctatus exhibits a somewhat intermediate pattern, possibly reflecting a more gradual shift in diet across much of its original range, allowing therefore the maintenance of higher genetic diversity across its current distribution.

Bottom Line: We discuss the likely mechanisms of speciation and the ecological characteristics of the extant communities, emphasizing the role of adaptation along environmental gradients and allopatric speciation in generating the exceptionally high beta diversity in Malagasy dung beetles.Phylogeographic analyses of selected species reveal complex patterns with evidence for genetic introgression between old taxa.The introduction of cattle to Madagascar 1500 years ago created a new abundant resource, onto which a few species haveshifted and thereby been able to greatly expand their geographical ranges.

View Article: PubMed Central - PubMed

Affiliation: Metapopulation Research Group, Department of Biosciences, University of Helsinki, P.O. Box 65, FI-00014, Finland. andreia.miraldo@helsinki.fi.

ABSTRACT
Madagascar has a rich fauna of dung beetles (Scarabaeinae and Aphodiinae) withalmost 300 species described to date. Like most other taxa in Madagascar, dung beetles exhibit an exceptionally high level of endemism (96% of the species). Here,we review the current knowledge of the origin and diversification of Malagasy dung beetles. Based on molecular phylogenies, the extant dung beetles originate from eight colonizations, of which four have given rise to extensive radiations. These radiations have occurred in wet forests, while the few extant species in the less successfulradiations occur in open and semi-open habitats. We discuss the likely mechanisms of speciation and the ecological characteristics of the extant communities, emphasizing the role of adaptation along environmental gradients and allopatric speciation in generating the exceptionally high beta diversity in Malagasy dung beetles. Phylogeographic analyses of selected species reveal complex patterns with evidence for genetic introgression between old taxa. The introduction of cattle to Madagascar 1500 years ago created a new abundant resource, onto which a few species haveshifted and thereby been able to greatly expand their geographical ranges.

No MeSH data available.