title: Long lifespans have evolved with long and monounsaturated fatty acids in birds.
abstract: The evolution of lifespan is a central question in evolutionary biology, begging the question why there is so large variation among taxa. Specifically, a central quest is to unravel proximate causes of ageing. Here, we show that the degree of unsaturation of liver fatty acids predicts maximum lifespan in 107 bird species. In these birds, the degree of fatty acid unsaturation is positively related to maximum lifespan across species. This is due to a positive effect of monounsaturated fatty acid content, while polyunsaturated fatty acid content negatively correlates with maximum lifespan. Furthermore, fatty acid chain length unsuspectedly increases with maximum lifespan independently of degree of unsaturation. These findings tune theories on the proximate causes of ageing while providing evidence that the evolution of lifespan in birds occurs in association with fatty acid profiles. This suggests that studies of proximate and ultimate questions may facilitate our understanding of these central evolutionary questions.
authors: Departamento de Ecología Evolutiva, Estación Biológica de Doñana - CSIC, c/ Américo Vespucio s/n, 41092, Sevilla, Spain. galvan@ebd.csic.es.
authors: Ismael
authors: I
authors: Galván
authors: Departamento de Medicina Experimental, Universidad de Lleida - Instituto de Investigación Biomédica de Lleida (IRBLleida), 25198, Lleida, Spain.
authors: Alba
authors: A
authors: Naudí
authors: Taps Old Rectory, 6040, Christiansfeld, Denmark.
authors: Johannes
authors: J
authors: Erritzøe
authors: Laboratoire d'Ecologie, Systématique et Evolution, Université Paris-Sud 11, Bâtiment 362, 91405, Orsay Cedex, France.
authors: Anders P
authors: AP
authors: Møller
authors: Departamento de Fisiología Animal II, Universidad Complutense de Madrid, c/ José Antonio Novais 2, 28040, Madrid, Spain.
authors: Gustavo
authors: G
authors: Barja
authors: Departamento de Medicina Experimental, Universidad de Lleida - Instituto de Investigación Biomédica de Lleida (IRBLleida), 25198, Lleida, Spain.
authors: Reinald
authors: R
authors: Pamplona
mesh_terms: D000375:Aging / Q000502:physiology; D000818:Animals; D005075:Biological Evolution; D001717:Birds / Q000378:metabolism*; D005227:Fatty Acids / Q000032:analysis*; D005231:Fatty Acids, Unsaturated / Q000032:analysis*; D008099:Liver / Q000737:chemistry; D008136:Longevity / Q000502:physiology*; D013045:Species Specificity
chemical_list: D005227:Fatty Acids; D005231:Fatty Acids, Unsaturated
keywords: Ageing; birds; homeoviscous longevity adaptation hypothesis; longevity