Trapped in the extinction vortex? Strong genetic effects in a declining vertebrate population

• Published in: BMC Evolutionary Biology
• Main Authors: Larsson Mikael, Pauliny Angela, Blomqvist Donald, Flodin Lars-Åke
• Format: Article in Journal/Newspaper
• Language: English
• Published: BMC 2010
• Subjects: Evolution; QH359-425; Calidris alpina
• Online Access: https://doi.org/10.1186/1471-2148-10-33; https://doaj.org/article/1f9c0a37993a49f1a8d65a7c848fa22f

Abstract Background Inbreeding and loss of genetic diversity are expected to increase the extinction risk of small populations, but detailed tests in natural populations are scarce. We combine long-term population and fitness data with those from two types of molecular markers to examine the role of genetic effects in a declining metapopulation of southern dunlins Calidris alpina schinzii , an endangered shorebird. Results The decline is associated with increased pairings between related individuals, including close inbreeding (as revealed by both field observations of parentage and molecular markers). Furthermore, reduced genetic diversity seems to affect individual fitness at several life stages. Higher genetic similarity between mates correlates negatively with the pair's hatching success. Moreover, offspring produced by related parents are more homozygous and suffer from increased mortality during embryonic development and possibly also after hatching. Conclusions Our results demonstrate strong genetic effects in a rapidly declining population, emphasizing the importance of genetic factors for the persistence of small populations.