title: On being the right size: increased body size is associated with reduced telomere length under natural conditions.
abstract: Evolution of body size is likely to involve trade-offs between body size, growth rate and longevity. Within species, larger body size is associated with faster growth and ageing, and reduced longevity, but the cellular processes driving these relationships are poorly understood. One mechanism that might play a key role in determining optimal body size is the relationship between body size and telomere dynamics. However, we know little about how telomere length is affected when selection for larger size is imposed in natural populations. We report here on the relationship between structural body size and telomere length in wild house sparrows at the beginning and end of a selection regime for larger parent size that was imposed for 4 years in an isolated population of house sparrows. A negative relationship between fledgling size and telomere length was present at the start of the selection; this was extended when fledgling size increased under the selection regime, demonstrating a persistent covariance between structural size and telomere length. Changes in telomere dynamics, either as a correlated trait or a consequence of larger size, could reduce potential longevity and the consequent trade-offs could thereby play an important role in the evolution of optimal body size.
authors.affiliation: Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, 7491 Trondheim, Norway thor.h.ringsby@ntnu.no.
authors.forename: Thor Harald
authors.initials: TH
authors.lastname: Ringsby
authors.affiliation: Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, 7491 Trondheim, Norway.
authors.forename: Henrik
authors.identifier: http://orcid.org/0000-0001-7804-1564
authors.initials: H
authors.lastname: Jensen
authors.affiliation: Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, 7491 Trondheim, Norway.
authors.forename: Henrik
authors.initials: H
authors.lastname: Pärn
authors.affiliation: Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, 7491 Trondheim, Norway.
authors.forename: Thomas
authors.initials: T
authors.lastname: Kvalnes
authors.affiliation: Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Graham Kerr Building, Glasgow G12 8QQ, UK.
authors.forename: Winnie
authors.initials: W
authors.lastname: Boner
authors.affiliation: Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Graham Kerr Building, Glasgow G12 8QQ, UK.
authors.forename: Robert
authors.initials: R
authors.lastname: Gillespie
authors.affiliation: Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, 7491 Trondheim, Norway.
authors.forename: Håkon
authors.identifier: http://orcid.org/0000-0001-9530-7096
authors.initials: H
authors.lastname: Holand
authors.affiliation: Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, 7491 Trondheim, Norway.
authors.forename: Ingerid Julie
authors.initials: IJ
authors.lastname: Hagen
authors.affiliation: Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, 7491 Trondheim, Norway.
authors.forename: Bernt
authors.initials: B
authors.lastname: Rønning
authors.affiliation: Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, 7491 Trondheim, Norway.
authors.forename: Bernt-Erik
authors.initials: BE
authors.lastname: Sæther
authors.affiliation: Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Graham Kerr Building, Glasgow G12 8QQ, UK.
authors.forename: Pat
authors.initials: P
authors.lastname: Monaghan
mesh_terms: D000818:Animals; D049628:Body Size / Q000235:genetics*; D008297:Male; D012641:Selection, Genetic; D046370:Sparrows / Q000235:genetics*; D016615:Telomere
keywords: Passer domesticus; body size; life-history trade-off; longevity; selection experiment; telomere length