ORCID Profile
0000-0003-3963-146X
Current Organisation
Universidad Austral de Chile
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Publisher: Wiley
Date: 19-08-2021
DOI: 10.1111/JBI.14227
Abstract: Accurate characterization of evolutionary units (species or populations) underlies all ecological and evolutionary studies and is crucial to conservation planning. Seascapes have long been thought to be highly permeable to gene flow, yet over the last decade building evidence has shown that barriers to gene flow in marine environments are much more common than previously thought. Here, we precisely characterize two barriers to gene flow in the tunicate Pyura chilensi s across 26° of latitude in the southeastern Pacific, assess their magnitude and explore their congruence with current biogeographical patterns of this region. The southeastern Pacific (SEP), from Ilo, Perú (17°S) to Chiloé, Chile (43°S). Pyura chilensis . We used a combination of highly polymorphic microsatellite markers and a 540 bp fragment of the Cytochrome Oxidase subunit I (COI) to compare in iduals s led at 26 localities spanning approximately 2500 km of the SEP. Genetic ersity was analysed using Bayesian clustering, haplotype networks, Isolation by Distance and cline models. A Coalescent simulator was used to estimate migration rates. The results from both the microsatellite and COI markers indicate the presence of two genetic discontinuities: one at 34°S and one at 39°S which coincide with genetic breaks reported for other species. Interestingly, we were able to determine that genetic transitions occur abruptly and within short geographical distances (~30 km) compared with previous studies of this tunicate. Coalescent simulations indicate the 34°S break is less permeable than the 39°S break, and gene flow appears to be mostly from north to south. Our results support other studies that show that seascapes are complex, and also highlight the importance of accurately s ling distribution ranges when making conclusions about gene flow. Overall, the two main biogeographical barriers to gene flow characterized in the southeastern Pacific are not homogeneously permeable and can be narrow ( km). These results are relevant for the management of fisheries in this region and specifically for this commercially important species.
Publisher: Springer Science and Business Media LLC
Date: 14-03-2018
Publisher: Wiley
Date: 14-09-2022
DOI: 10.1111/MEC.16672
Abstract: Gracilaria chilensis is the main cultivated seaweed in Chile. The low genetic ersity observed in the Chilean populations has been associated with the over‐exploitation of natural beds and/or the founder effect that occurred during post‐glacial colonization from New Zealand. How these processes have affected its evolutionary trajectory before farming and incipient domestication is poorly understood. In this study, we used 2232 single nucleotide polymorphisms (SNPs) to assess how the species' evolutionary history in New Zealand (its region of origin), the founder effect linked to transoceanic dispersion and colonization of South America, and the recent over‐exploitation of natural populations have influenced the genetic architecture of G. chilensis in Chile. The contrasting patterns of genetic ersity and structure observed between the two main islands in New Zealand attest to the important effects of Quaternary glacial cycles on G. chilensis . Approximate Bayesian Computation (ABC) analyses indicated that Chatham Island and South America were colonized independently near the end of the Last Glacial Maximum and emphasized the importance of coastal and oceanic currents during that period. Furthermore, ABC analyses inferred the existence of a recent and strong genetic bottleneck in Chile, matching the period of over‐exploitation of the natural beds during the 1970s, followed by rapid demographic expansion linked to active clonal propagation used in farming. Recurrent genetic bottlenecks strongly eroded the genetic ersity of G. chilensis prior to its cultivation, raising important challenges for the management of genetic resources in this incipiently domesticated species.
No related grants have been discovered for Suany Quesada-Calderon.