Pervasive horizontal transmission of Wolbachia in natural populations of closely related and widespread tropical skipper butterflies.

Background: The endosymbiotic relationship between Wolbachia bacteria and insects has been of interest for many years due to their diverse types of host reproductive phenotypic manipulation and potential role in the host's evolutionary history and population dynamics. Even though infection rates are high in Lepidoptera and specifically in butterflies, and reproductive manipulation is present in these taxa, less attention has been given to understanding how Wolbachia is acquired and maintained in their natural populations, across and within species having continental geographical distributions.

Results: We used whole genome sequencing data to investigate the phylogenetics, demographic history, and infection rate dynamics of Wolbachia in four species of the Spicauda genus of skipper butterflies (Lepidoptera: Hesperiidae), a taxon that presents sympatric and often syntopic distribution, with drastic variability in species abundance in the Neotropical region.

Evolutionary genomics of oceanic island radiations.

A recurring feature of oceanic archipelagos is the presence of adaptive radiations that generate endemic, species-rich clades that can offer outstanding insight into the links between ecology and evolution. Recent developments in evolutionary genomics have contributed towards solving long-standing questions at this interface. Using a comprehensive literature search, we identify studies spanning 19 oceanic archipelagos and 110 putative adaptive radiations, but find that most of these radiations have not yet been investigated from an evolutionary genomics perspective.

Genomics of Parallel Ecological Speciation in Lake Victoria Cichlids.

The genetic basis of parallel evolution of similar species is of great interest in evolutionary biology. In the adaptive radiation of Lake Victoria cichlid fishes, sister species with either blue or red-back male nuptial coloration have evolved repeatedly, often associated with shallower and deeper water, respectively. One such case is blue and red-backed Pundamilia species, for which we recently showed that a young species pair may have evolved through "hybrid parallel speciation".

Genomic landscape of early ecological speciation initiated by selection on nuptial colour.

Ecological speciation is the evolution of reproductive isolation as a consequence of direct divergent natural selection or ecologically mediated divergent sexual selection. While the genomic signature of the former has been extensively studied in recent years, only few examples exist for genomic differentiation where environment-dependent sexual selection has played an important role. Here, we describe a very young (~90 years old) population of threespine sticklebacks exhibiting phenotypic and genomic differentiation between two habitats within the same pond.