RESUMO
The Ethiopian highlands represent a remarkable biodiversity 'hot spot' with a very high number of endemic species, even among vertebrates. Ethiopian representatives of a species complex of speckled brush-furred rats (Lophuromys flavopunctatus sensu lato) inhabit highland habitats ranging from low-elevation forests to Afroalpine grasslands. These may serve as a suitable model for understanding evolutionary processes leading to high genetic and ecological diversity in montane biodiversity hot spots. Here, we analyse the most comprehensive genetic data set of this group, comprising 315 specimens (all nine putative Ethiopian Lophuromys taxa sampled across most of their distribution ranges) genotyped at one mitochondrial and four nuclear markers, and thousands of SNPs from ddRAD sequencing. We performed phylogenetic analyses, delimited species and mapped their distribution and estimated divergence time between species (under the species-tree framework) and mitochondrial lineages. We found significant incongruence between mitochondrial and nuclear phylogenies, most probably caused by multiple interspecific introgression events. We discuss alternative scenarios of Ethiopian Lophuromys evolution, from retention of ancestral polymorphism to hybridization upon secondary contact of partially reproductively isolated lineages leading to reticulate evolution. Finally, we use the diversity of the speckled brush-furred rats for the description of the main biogeographic patterns in the fauna of the Ethiopian highlands.
Assuntos
Biodiversidade , Evolução Biológica , Murinae , Animais , DNA Mitocondrial/genética , Ecossistema , Etiópia , FilogeniaRESUMO
Complete mitochondrial genomes of four species of Ethiopian speckled brush-furred rats Lophuromys (L. chrysopus, L. menageshae, L. melanonyx, and L. simensis) were assembled for the first time. We provide data concerning the sequencing, assembly, and annotation of the obtained mitogenomes; compare two widely used circular-genome annotation tools (MITOS and MitoZ), and discuss relevant points concerning relationships within both Ethiopian Lophuromys and the Muridae family.
RESUMO
Valentin's rock lizard (Darevskia valentini) is suggested to be the parent for several parthenogenetic species (e.g., D. armeniaca, D. bendimahiensis, D. sapphirina, and D. unisexualis) that evolved through hybridization. Complex evolutionary processes (including reticulate evolution) are occurring within the areas where Valentin's rock lizard coexists with these and other rock lizards. Hence, a detailed biological specification of this species is important for understanding how vertebrates evolve. Valentin's rock lizard is a long-lived (up to 9 years), small diurnal lizard with larger females than males, which is unlike other species of the genus. Their relatively large eggs and early reproduction period, which occurs just after emergence from winter shelters, are adaptations for living in a high elevation climate (higher than 2 000 m a.s.l.). Their body temperatures (31-32 °Ð¡) are comparable to body temperatures of rock lizards living in milder climates, though female body temperature is more dependent on substrate temperature and basking due to their lower activity than that found in males. Population density fluctuates from several individuals to several hundred per hectare and is not affected by parthenogen coexistence, although hybrids do occur in sexually biased populations where males are more common than females. The male home range is larger than that of females, though these home ranges broadly overlap. Prey is not limited in the mountain meadows and Valentin's rock lizards feed on a great variety of arthropods. Infanticide occurs in high-density populations.