Surviving with low genetic diversity: the case of albatrosses

• Main Authors: Milot, Emmanuel, Weimerskirch, Henri, Duchesne, Pierre, Bernatchez, Louis
• Other Authors: Départment de Biologie, Université Laval Québec (ULaval), Centre d'Études Biologiques de Chizé (CEBC), Centre National de la Recherche Scientifique (CNRS), Département de Biologie
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2007
• Subjects: genetic diversity; life-history traits; albatrosses; AFLP; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; [SDE.ES]Environmental Sciences/Environmental and Society; [SDE.MCG]Environmental Sciences/Global Changes; Diomedea exulans; Wandering Albatross
• Online Access: https://hal.science/hal-00183595

International audience Low genetic diversity is predicted to negatively impact species viability and has been a central concern for conservation. In contrast, the possibility that some speciesmay thrive in spite of a relatively poor diversity has received little attention. The wandering and Amsterdam albatrosses (Diomedea exulans and Diomedea amsterdamensis) are long-lived seabirds standing at an extreme along the gradient of life strategies, having traits that may favour inbreeding and low genetic diversity. Divergence time of the two species is estimated at 0.84 Myr ago from cytochrome b data.We tested the hypothesis that both albatrosses inherited poor genetic diversity from their common ancestor. Within the wandering albatross, per cent polymorphic loci and expected heterozygosity at amplified fragment length polymorphisms were approximately one-third of the minimal values reported in other vertebrates. Genetic diversity in the Amsterdam albatross, which is recovering from a severe bottleneck, was about twice as low as in the wandering albatross. Simulations supported the hypothesis that genetic diversity in albatrosses was already depleted prior to their divergence. Given the generally high breeding success of these species, it is likely that they are not suffering much from their impoverished diversity. Whether albatrosses are unique in this regard is unknown, but they appear to challenge the classical view about the negative consequences of genetic depletion on species survival.