ORCID Profile
0000-0003-4223-0149
Current Organisation
CONICET Mendoza - IBAM
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Publisher: Cold Spring Harbor Laboratory
Date: 19-08-2021
DOI: 10.1101/2021.08.18.456742
Abstract: Understanding how wild populations respond to climatic shifts is a fundamental goal of biological research in a fast-changing world. The Southern Ocean represents a fascinating system for assessing large-scale climate-driven biological change, as it contains extremely isolated island groups within a predominantly westerly, circumpolar wind and current system. The blue-eyed shags ( Leucocarbo spp.) represent a paradoxical Southern Ocean seabird radiation a circumpolar distribution implies strong dispersal capacity yet their speciose nature suggests local adaptation and isolation. Here we use genetic tools in an attempt to resolve this paradox. Southern Ocean. 17 species and subspecies of blue-eyed shags ( Leucocarbo spp.) across the geographical distribution of the genus. Here we use mitochondrial and nuclear sequence data to conduct the first global genetic analysis of this group using a temporal phylogenetic framework to test for rapid speciation. Our analysis reveals remarkably shallow evolutionary histories among island-endemic lineages, consistent with a recent high-latitude circumpolar radiation. This rapid sub-Antarctic expansion contrasts with significantly deeper lineages detected in more temperate regions such as South America and New Zealand that may have acted as glacial refugia. The dynamic history of high-latitude expansions is further supported by ancestral demographic and biogeographic reconstructions. The circumpolar distribution of blue-eyed shags, and their highly dynamic evolutionary history, potentially make Leucocarbo a strong sentinel of past and ongoing Southern Ocean ecosystem change given their sensitivity to climatic impacts.
Publisher: Wiley
Date: 29-01-2015
Abstract: Microsatellite loci are ideal for testing hypotheses relating to genetic segregation at fine spatio-temporal scales. They are also conserved among closely related species, making them potentially useful for clarifying interspecific relationships between recently erged taxa. However, mutations at primer binding sites may lead to increased non lification, or disruptions that may result in decreased polymorphism in nontarget species. Furthermore, high mutation rates and constraints on allele size may also with evolutionary time, promote an increase in convergently evolved allele size classes, biasing measures of interspecific genetic differentiation. Here, we used next-generation sequencing to develop microsatellite markers from a shotgun genome sequence of the sub-Antarctic seabird, the thin-billed prion (Pachyptila belcheri), that we tested for cross-species lification in other Pachyptila and related sub-Antarctic species. We found that heterozygosity decreased and the proportion of non lifying loci increased with phylogenetic distance from the target species. Surprisingly, we found that species trees estimated from interspecific FST provided better approximations of mtDNA relationships among the studied species than those estimated using DC , even though FST was more affected by null alleles. We observed a significantly nonlinear second order polynomial relationship between microsatellite and mtDNA distances. We propose that the loss of linearity with increasing mtDNA distance stems from an increasing proportion of homoplastic allele size classes that are identical in state, but not identical by descent. Therefore, despite high cross-species lification success and high polymorphism among the closely related Pachyptila species, we caution against the use of microsatellites in phylogenetic inference among distantly related taxa.
Publisher: Springer Science and Business Media LLC
Date: 19-06-2018
Publisher: Springer Science and Business Media LLC
Date: 18-12-2021
DOI: 10.1007/S00438-021-01845-3
Abstract: Interspecific introgression can occur between species that evolve rapidly within an adaptive radiation. Pachyptila petrels differ in bill size and are characterised by incomplete reproductive isolation, leading to interspecific gene flow. Salvin’s prion ( Pachyptila salvini ), whose bill width is intermediate between broad-billed ( P. vittata ) and Antarctic ( P. desolata ) prions, evolved through homoploid hybrid speciation. MacGillivray’s prion ( P. macgillivrayi ), known from a single population on St Paul (Indian Ocean), has a bill width intermediate between salvini and vittata and could also be the product of interspecies introgression or hybrid speciation. Recently, another prion population phenotypically similar to macgillivrayi was discovered on Gough (Atlantic Ocean), where it breeds 3 months later than vittata . The similarity in bill width between the medium-billed birds on Gough and macgillivrayi suggest that they could be closely related. In this study, we used genetic and morphological data to infer the phylogenetic position and evolutionary history of P. macgillivrayi and the Gough medium-billed prion relative other Pachyptila taxa, to determine whether species with medium bill widths evolved through common ancestry or convergence. We found that Gough medium-billed prions belong to the same evolutionary lineage as macgillivrayi , representing a new population of MacGillivray’s prion that originated through a colonisation event from St Paul. We show that macgillivrayi ’s medium bill width evolved through ergence (genetic drift) and independently from that of salvini , which evolved through hybridisation (gene flow). This represents the independent convergence towards a similarly medium-billed phenotype. The newly discovered MacGillivray’s prion population on Gough is of utmost conservation relevance, as the relict macgillivrayi population in the Indian Ocean is very small.
Location: Argentina
Location: Argentina
Location: Argentina
Location: Argentina
Location: Argentina
Location: Argentina
No related grants have been discovered for Luciano Calderón.