Genome size and longevity

Abstract

Our lack of understanding of the great variation in eukaryote genome size (the C-value paradox) has given rise to a search for clues as to its phenotypic consequences 1 Jockusch E.L. An evolutionary correlate of genome size change in plethodontid salamanders. Proc. R. Soc. London Ser. B. 1997; 264: 597-604 Crossref Scopus (63) Google Scholar , 2 Beaton M.J. Cavalier-Smith T. Eukaryotic non-coding DNA is functional evidence from the differential scaling of cryptomonad genomes. Proc. R. Soc. London Ser. B. 1999; 266: 2053-2059 Crossref PubMed Scopus (49) Google Scholar . While C-value has been related to cellular and developmental traits in some groups 2 Beaton M.J. Cavalier-Smith T. Eukaryotic non-coding DNA is functional evidence from the differential scaling of cryptomonad genomes. Proc. R. Soc. London Ser. B. 1999; 266: 2053-2059 Crossref PubMed Scopus (49) Google Scholar , the results are equivocal and any direct link with whole-organism fitness parameters has remained elusive 1 Jockusch E.L. An evolutionary correlate of genome size change in plethodontid salamanders. Proc. R. Soc. London Ser. B. 1997; 264: 597-604 Crossref Scopus (63) Google Scholar . Lifespan is an organismal trait with important fitness consequences. Interspecific differences in longevity are likely to be related to differences in the levels of genome and tissue maintenance, damage and repair 3 Kirkwood T.B.L. Comparative aspects of longevity. in: Finch C.E. Schneider E.L. Handbook of the Biology of Aging. Van Nostrand Reinhold, 1985: 27-45 Google Scholar . Although there is some evidence of a relationship between the duration of the life cycle and genome size in vascular plants 4 Finch C.E. Longevity, Senescence, and the Genome. University of Chicago Press, 1990 Google Scholar , the potential link between lifespan and C-value has not been examined within any group of organisms. We have examined this link using birds, one of the few taxa for which there are now reasonably good data both on genome sizes and on maximum longevity under natural conditions, for a broad range of species.