On being the right size: increased body size is associated with reduced telomere length under natural conditions.
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.
['Ringsby|Thor Harald|TH|', 'Jensen|Henrik|H|http://orcid.org/0000-0001-7804-1564', 'Pärn|Henrik|H|', 'Kvalnes|Thomas|T|', 'Boner|Winnie|W|', 'Gillespie|Robert|R|', 'Holand|Håkon|H|http://orcid.org/0000-0001-9530-7096', 'Hagen|Ingerid Julie|IJ|', 'Rønning|Bernt|B|', 'Sæther|Bernt-Erik|BE|', 'Monaghan|Pat|P|']
D000818:Animals D049628:Body Size D008297:Male D012641:Selection, Genetic D046370:Sparrows D016615:Telomere
body size telomere length longevity Passer domesticus life-history trade-off selection experiment