title: Experimental evolution of slowed cognitive aging in Drosophila melanogaster.
abstract: Reproductive output and cognitive performance decline in parallel during aging, but it is unknown whether this reflects a shared genetic architecture or merely the declining force of natural selection acting independently on both traits. We used experimental evolution in Drosophila melanogaster to test for the presence of genetic variation for slowed cognitive aging, and assess its independence from that responsible for other traits' decline with age. Replicate experimental populations experienced either joint selection on learning and reproduction at old age (Old + Learning), selection on late-life reproduction alone (Old), or a standard two-week culture regime (Young). Within 20 generations, the Old + Learning populations evolved a slower decline in learning with age than both the Old and Young populations, revealing genetic variation for cognitive aging. We found little evidence for a genetic correlation between cognitive and demographic aging: although the Old + Learning populations tended to show higher late-life fecundity than Old populations, they did not live longer. Likewise, selection for late reproduction alone did not result in improved late-life learning. Our results demonstrate that Drosophila harbor genetic variation for cognitive aging that is largely independent from genetic variation for demographic aging and suggest that these two aspects of aging may not necessarily follow the same trajectories.
authors.affiliation: Department of Animal Ecology, Uppsala University, 752 36, Uppsala, Sweden.|Department of Ecology and Evolution, University of Lausanne, CH 1015, Lausanne, Switzerland.
authors.forename: Martyna K
authors.initials: MK
authors.lastname: Zwoinska
authors.affiliation: Department of Animal Ecology, Uppsala University, 752 36, Uppsala, Sweden.
authors.forename: Alexei A
authors.initials: AA
authors.lastname: Maklakov
authors.affiliation: Department of Ecology and Evolution, University of Lausanne, CH 1015, Lausanne, Switzerland.
authors.forename: Tadeusz J
authors.initials: TJ
authors.lastname: Kawecki
authors.affiliation: Department of Ecology and Evolution, University of Lausanne, CH 1015, Lausanne, Switzerland.|School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
authors.forename: Brian
authors.initials: B
authors.lastname: Hollis
mesh_terms: D000818:Animals; D005075:Biological Evolution; D000066492:Cognitive Aging; D004331:Drosophila melanogaster / Q000235:genetics / Q000502:physiology*; D005260:Female; D014644:Genetic Variation; D007858:Learning; D008297:Male; D012098:Reproduction
keywords: Cognitive aging; Drosophila; experimental evolution; genetic architecture; learning; trade-off