Evolutionary History, Genomic Adaptation to Toxic Diet and Extinction of the Carolina Parakeet

Year: 2019

Type: article

Abstract: As the only endemic neotropical parrot to have recently lived in the northern hemisphere, the Carolina parakeet (Conuropsis carolinensis) was an iconic North American bird. The last surviving specimen died in the Cincinnati Zoo in 1918 [1]. The cause of its extinction remains contentious: besides excessive mortality associated to habitat destruction and active hunting, their survival could have been negatively affected by its range having become increasingly patchy [2] or by the exposure to poultry pathogens [3, 4]. In addition, the Carolina parakeet showed a predilection for cockleburs, an herbaceous plant that contains a powerful toxin, carboxyatractyloside, or CAT [5], which did not seem to affect them but made the birds notoriously toxic to most predators [3]. To explore the demographic history of this bird, we generated the complete genomic sequence of a preserved specimen held in a private collection in Espinelves (Girona, Spain), as well as of a close extant relative, Aratinga solstitialis. We identified two non-synonymous genetic changes in two highly conserved proteins known to interact with CAT that could underlie a specific dietary adaptation to this toxin. Our genomic analyses did not reveal evidence of a dramatic past demographic decline in the Carolina parakeet; also, its genome did not exhibit the long runs of homozygosity that are signals of recent inbreeding and are typically found in endangered species. As such, our results suggest its extinction was an abrupt process and thus likely solely attributable to human causes.

Source: Current Biology

DOI: 10.1016/j.cub.2019.10.066

Institutions: University of Vienna, Consejo Superior de Investigaciones Científicas, Universitat Pompeu Fabra, Institut de Biologia Evolutiva, University of Copenhagen, BGI Group (China), Institut de Recerca de la Biodiversitat de la Universitat de Barcelona, Universitat de Barcelona, Northwestern Polytechnical University, AIMST University, Stockholm University, Science for Life Laboratory, Institució Catalana de Recerca i Estudis Avançats, Barcelona Institute of Science and Technology, Centre for Genomic Regulation, Swedish Museum of Natural History, Universitat Autònoma de Barcelona, Institut Català de Paleontologia Miquel Crusafont, Kunming Institute of Zoology, Chinese Academy of Sciences, China National GeneBank, State Key Laboratory of Genetic Resources and Evolution, Universidade do Porto, Centro Interdisciplinar de Investigação Marinha e Ambiental, Norwegian University of Science and Technology

Language: English

Topic: Genetic diversity and population structure

Subfield: Genetics

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

Open Access status: hybrid

Estimated APC paid: $5,200

Funders: Howard Hughes Medical Institute, Centres de Recerca de Catalunya, Generalitat de Catalunya, Ministerio de Economía y Competitividad, Knut och Alice Wallenbergs Stiftelse, Vetenskapsrådet, Science for Life Laboratory, European Research Council, Fundação para a Ciência e a Tecnologia, European Regional Development Fund, Kunming Institute of Zoology, Chinese Academy of Sciences, Uppsala Multidisciplinary Center for Advanced Computational Science, National Institute of Mental Health

OpenAlex ID: W2958615016