Multiple paths toward repeated phenotypic evolution in the spiny-leg adaptive radiation (Tetragnatha; Hawai'i)

The repeated evolution of phenotypes provides clear evidence for the role of natural selection in driving evolutionary change. However, the evolutionary origin of repeated phenotypes can be difficult to disentangle as it can arise from a combination of factors such as gene flow, shared ancestral polymorphisms or mutation. Here, we investigate the presence of these evolutionary processes in the Hawaiian spiny-leg Tetragnatha adaptive radiation, which includes four microhabitat-specialists or ecomorphs, with different body pigmentation and size (Green, Large Brown, Maroon, and Small Brown). We investigated the evolutionary history of this radiation using 76 newly generated low-coverage, whole-genome resequenced samples, along with phylogenetic and population genomic tools. Considering the Green ecomorph as the ancestral state, our results suggest that the Green ecomorph likely re-evolved once, the Large Brown and Maroon ecomorphs evolved twice and the Small Brown evolved three times. We found that the evolution of the Maroon and Small Brown ecomorphs likely involved ancestral hybridization events, while the Green and Large Brown ecomorphs likely evolved through novel mutations, despite a high rate of incomplete lineage sorting in the dataset. Our findings demonstrate that the repeated evolution of ecomorphs in the Hawaiian spiny-leg Tetragnatha is influenced by multiple evolutionary processes.publishedVersio

A comprehensive mitogenome phylogeny of the avian tribe Arini (Arinae: Psittacidae) with emphasis in Pyrrhura species

The tribe Arini is the most diverse group of Neotropical parrots, and it includes approximately 158 species distributed in at least 32 genera. These parrots have been largely affected by habitat loss, fragmentation, and the illegal wildlife trade market. In the past, many molecular phylogenies have been inferred based on both nuclear and mitochondrial sequences. However, the evolutionary relationships between some taxa remain unclear, especially within the Pyrrhura genus, the most diverse genus within the tribe. This study used whole-genome shotgun sequencing to obtain mitochondrial genome sequences of 48 Pyrrhura samples, representing 22 Pyrrhura species. Using this data together with all publicly available mitogenome sequences, we inferred the most comprehensive mitogenome-based phylogeny of the tribe Arini. The obtained phylogeny shows better resolved clades and higher support than previous phylogenetic studies of Arini and Pyrrhura. Previous studies categorized Pyrrhura species in three groups, including P. cruentata, the picta-leucotis complex, and the ‘remaining Pyrrhura species’. The evolutionary relationships within the last two groups have been poorly studied so far. Based on our mitogenome phylogeny, we divide the ‘remaining Pyrrhura species’ into the following groups: Clade 1: P. rupicola; clade 2: P. frontalis, P. molinae, P. perlata, and P. lepida; clade 3: P. hoffmani, and P. rhodocephala; clade 4: P. egregia, P. calliptera, and P. melanura. Previous works placed P. albipectus and P. devillei in clades 4 and 2 respectively. On the other hand, the P. orcesi could form an independent clade within the remaining Pyrrhura species. The systematic positions of P. viridicata and P. hoematotis remain a mystery due to lack of data. hoematotis remain a mystery due to lack of data. Finally, a CYTB-CR-based phylogeny was inferred to further study the relationships within the clade 4 of the ‘remaining Pyrrhura species’, finding that P. melanura taxa form two separate clades. The first includes P. melanura taxa from Venezuela: P. m. souancei, P. calliptera, and P. albipectus. The second includes P. melanura taxa from Western South America, P. m. berlepschi, and P. m. pacifica. Moreover, species distribution models (SDMs) provided further support to the isolation of P. m. souancei and P. m. pacifica from the nominal race. Our results suggest that P. melanura subspecies are geographically and genetically separated from the nominal race. Future studies should increase the sample size and involve morphological analysis

Multiple paths toward repeated phenotypic evolution in the spiny-leg adaptive radiation (Tetragnatha; Hawai'i).

Funder: Peder Sather Center for Advanced Study; doi: http://dx.doi.org/10.13039/100012388Funder: Fulbright/CONICYT Doctoral FellowshipFunder: Integrative Biology Department and the Graduate Division of UC BerkeleyFunder: Margaret C. Walker FundFunder: Alexander von Humboldt Postdoctoral FellowshipFunder: Sigma Xi; doi: http://dx.doi.org/10.13039/100011084The repeated evolution of phenotypes provides clear evidence for the role of natural selection in driving evolutionary change. However, the evolutionary origin of repeated phenotypes can be difficult to disentangle as it can arise from a combination of factors such as gene flow, shared ancestral polymorphisms or mutation. Here, we investigate the presence of these evolutionary processes in the Hawaiian spiny-leg Tetragnatha adaptive radiation, which includes four microhabitat-specialists or ecomorphs, with different body pigmentation and size (Green, Large Brown, Maroon, and Small Brown). We investigated the evolutionary history of this radiation using 76 newly generated low-coverage, whole-genome resequenced samples, along with phylogenetic and population genomic tools. Considering the Green ecomorph as the ancestral state, our results suggest that the Green ecomorph likely re-evolved once, the Large Brown and Maroon ecomorphs evolved twice and the Small Brown evolved three times. We found that the evolution of the Maroon and Small Brown ecomorphs likely involved ancestral hybridization events, while the Green and Large Brown ecomorphs likely evolved through novel mutations, despite a high rate of incomplete lineage sorting in the dataset. Our findings demonstrate that the repeated evolution of ecomorphs in the Hawaiian spiny-leg Tetragnatha is influenced by multiple evolutionary processes