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Genomics reveal the origins and current structure of a genetically depauperate freshwater species in its introduced Alaskan range

Authors :
Matthew A. Campbell
Matthew C. Hale
Chase S. Jalbert
Kristine Dunker
Adam J. Sepulveda
J. Andrés López
Jeffrey A. Falke
Peter A. H. Westley
Source :
Evolutionary Applications, Vol 16, Iss 6, Pp 1119-1134 (2023)
Publication Year :
2023
Publisher :
Wiley, 2023.

Abstract

Abstract Invasive species are a major threat to global biodiversity, yet also represent large‐scale unplanned ecological and evolutionary experiments to address fundamental questions in nature. Here we analyzed both native and invasive populations of predatory northern pike (Esox lucius) to characterize landscape genetic variation, determine the most likely origins of introduced populations, and investigate a presumably postglacial population from Southeast Alaska of unclear provenance. Using a set of 4329 SNPs from 351 individual Alaskan northern pike representing the most widespread geographic sampling to date, our results confirm low levels of genetic diversity in native populations (average 𝝅 of 3.18 × 10−4) and even less in invasive populations (average 𝝅 of 2.68 × 10−4) consistent with bottleneck effects. Our analyses indicate that invasive northern pike likely came from multiple introductions from different native Alaskan populations and subsequently dispersed from original introduction sites. At the broadest scale, invasive populations appear to have been founded from two distinct regions of Alaska, indicative of two independent introduction events. Genetic admixture resulting from introductions from multiple source populations may have mitigated the negative effects associated with genetic bottlenecks in this species with naturally low levels of genetic diversity. Genomic signatures strongly suggest an excess of rare, population‐specific alleles, pointing to a small number of founding individuals in both native and introduced populations consistent with a species' life history of limited dispersal and gene flow. Lastly, the results strongly suggest that a small isolated population of pike, located in Southeast Alaska, is native in origin rather than stemming from a contemporary introduction event. Although theory predicts that lack of genetic variation may limit colonization success of novel environments, we detected no evidence that a lack of standing variation limited the success of this genetically depauperate apex predator.

Details

Language :
English
ISSN :
17524571
Volume :
16
Issue :
6
Database :
Directory of Open Access Journals
Journal :
Evolutionary Applications
Publication Type :
Academic Journal
Accession number :
edsdoj.94ee5d65e2c4246a3df3997bcb0c477
Document Type :
article
Full Text :
https://doi.org/10.1111/eva.13556