Combining morphology and molecular data to improveDrosophila paulistorum(Diptera, Drosophilidae) taxonomic status

Abstract

The willistoni species subgroup has been the subject of several studies since the latter half of the past century and is considered a Neotropical model for evolutionary studies, given the many levels of reproductive isolation and different evolutionary stages occurring within them. Here we present for the first time a phylogenetic reconstruction combining morphological characters and molecular data obtained from 8 gene fragments (COI, COII, Cytb, Adh, Ddc, Hb, kl-3 and per). Some relationships were incongruent when comparing morphological and molecular data. Also, morphological data presented some unresolved polytomies, which could reflect the very recent divergence of the subgroup. The total evidence phylogenetic reconstruction presented well-supported relationships and summarized the results of all analyses. The diversification of the willistoni subgroup began about 7.3 Ma with the split of D. insularis while D.paulistorum complex has a much more recent diversification history, which began about 2.1 Ma and apparently has not completed the speciation process, since the average time to sister species separation is one million years, and some entities of the D. paulistorum complex diverge between 0.3 and 1 Ma. Based on the obtained data, we propose the categorization of the former "semispecies" of D. paulistorum as a subspecies and describe the subspecies D. paulistorum amazonian, D. paulistorum andeanbrazilian, D. paulistorum centroamerican, D. paulistorum interior, D. paulistorum orinocan and D. paulistorum transitional.

Multiple introgressions shape mitochondrial evolutionary history inDrosophila paulistorumand theDrosophila willistonigroup

“…Unfortunately, sequence data is not available for all species in the bocainensis subgroup, but D. nebulosa, which is included in our phylogeny, branches basally to b. A similar position was observed for three other representatives of the bocainensis subgroup, D. capricorni, D. fumipennis and D. sucinea in previously published single gene trees [54]. No sequence data is available for any alagitans species.…”

“…All semispecies also carry the bacterial endosymbiont Wolbachia, which provides mutualistic functions and causes premating isolation between members of different semispecies pairs [47][48][49][50][51]. The whole willistoni subgroup is a recent radiation and phylogenetic incongruences between D. paulistorum nuclear and mitochondrial evolutionary histories [52][53][54] suggest that hybridization and introgression events between semispecies may have occurred in the past [53].…”

Interpopulation variation of transposable elements of the hAT superfamily in Drosophila willistoni (Diptera: Drosophilidae): in-situ approach

“…Additionally, the lower diversity of the mar sequences observed in D. paulistorum- L06 (8.99%) compared to the sequences found in D. paulistorum -L12 (24.51%) may be a function of the different geographical origins of the strains. D. paulistorum- L12 is Andean-Brazilian, from within the large geographic region of origin (Brazil, Ecuador, Peru, Colombia, and Venezuela) ( Zanini et al, 2018 ). D. paulistorum- L06 from San Salvador (El Salvador) has been maintained in the laboratory since 1955 ( Kim et al, 2021 ) ( Figure 3 ), explaining the lower diversity of mar in this genome.…”

Is the demise of plant taxonomy in sight? Maybe yes, maybe no…

“…According to Rouhan and Gaudeul (2021) molecular taxonomy is at disadvantage because of the potential lack of genetic divergence in sister-species sharing recent origins, i.e., they will share alleles due to recent ancestry. Thus, the amalgamation of different datasets, e.g., morphology and molecular, is desirable to more accurately infer evolutionary process (Hillis 1987;Humphries 1988;Patterson et al 1993;Pennington 1996;Scotland et al 2003;Martynov 2012;Zanini et al 2018). In addition, the conflict emerging from combining the data sets should be considered in the outcomes (Bremer 1996;Petersen and Seberg 1998;Wiens 2004).…”