0000000000446946
AUTHOR
Andreas Hapke
Hybridization of mouse lemurs: different patterns under different ecological conditions
Abstract Background Several mechanistic models aim to explain the diversification of the multitude of endemic species on Madagascar. The island's biogeographic history probably offered numerous opportunities for secondary contact and subsequent hybridization. Existing diversification models do not consider a possible role of these processes. One key question for a better understanding of their potential importance is how they are influenced by different environmental settings. Here, we characterized a contact zone between two species of mouse lemurs, Microcebus griseorufus and M. murinus, in dry spiny bush and mesic gallery forest that border each other sharply without intermediate habitats…
Population Genetics, Parasitism, and Long-Term Population Dynamics of Microcebus murinus in Littoral Forest Fragments of South-Eastern Madagascar
Habitat fragmentation is a major threat for lemur conservation, as it reduces population sizes to levels that are nonviable in the long term. Alternatively, isolated populations may have great importance for conservation, as some are well protected and some lemurs do well even in small areas. Hence, knowing which characteristics indicate a population under threat is of paramount importance for conservation action. We studied Microcebus murinus populations confined to forest fragments of different sizes and states of degradation in south-eastern Madagascar to investigate relationships between population size, population dynamics, genetic diversity of coding and noncoding DNA, and infection r…
Discrepant partitioning of genetic diversity in mouse lemurs and dwarf lemurs--biological reality or taxonomic bias?
Unequal degrees of taxonomic subdivision can pose problems for research that relies on cross-taxon comparisons of biogeographic patterns. Numerous species of lemurs have been described in recent years. These descriptions were unevenly distributed over the genera of lemurs as exemplified by the closely related mouse lemurs (Microcebus spp.) and dwarf lemurs (Cheirogaleus spp.). According to previous studies, these genera display striking differences such as many versus few species, small versus large distributions, and small versus large mitochondrial divergence within and between species. We questioned if these differences reflect the biological reality or a biased taxonomic subdivision, wh…
Range Shifts of Mouse Lemurs in South-Eastern Madagascar: Evidence from Mitochondrial Genetic Data
The gray mouse lemur, Microcebus murinus, occurs mainly in dry forests in western Madagascar, but its distribution extends into humid littoral forests in the south-eastern Anosy Region. We sequenced the mitochondrial hypervariable region 1 for 282 M. murinus individuals from 13 south-eastern study sites. The spatial distribution of mitochondrial haplotypes and the varying genetic distances within two haplotype clades indicated a trend of decreasing genetic diversity towards the south-eastern margin of the range. Rufous mouse lemurs, Microcebus cf. rufus, have a complementary distribution in south-eastern Madagascar which does not overlap with that of M. murinus. Taken together, the spatial …
Hybridization between mouse lemurs in an ecological transition zone in southern Madagascar
Hybrid zones in ecotones can be useful model systems for the study of evolutionary processes that shape the distribution and discreteness of species. Such studies could be important for an improved understanding of the complex biogeography of Madagascar, which is renowned for its outstanding degree of small-scale endemism. Certain forest remnants in central Madagascar indicate that transitional corridors across the island could have connected microendemics in different forest types in the past. Evolutionary processes in such corridors are difficult to study because most of these corridors have disappeared due to deforestation in central Madagascar. We studied a hybrid zone in one of the few…