title: Evolution under dietary restriction increases male reproductive performance without survival cost.
abstract: Dietary restriction (DR), a reduction in nutrient intake without malnutrition, is the most reproducible way to extend lifespan in a wide range of organisms across the tree of life, yet the evolutionary underpinnings of the DR effect on lifespan are still widely debated. The leading theory suggests that this effect is adaptive and results from reallocation of resources from reproduction to somatic maintenance, in order to survive periods of famine in nature. However, such response would cease to be adaptive when DR is chronic and animals are selected to allocate more resources to reproduction. Nevertheless, chronic DR can also increase the strength of selection resulting in the evolution of more robust genotypes. We evolved Drosophila melanogaster fruit flies on 'DR', 'standard' and 'high' adult diets in replicate populations with overlapping generations. After approximately 25 generations of experimental evolution, male 'DR' flies had higher fitness than males from 'standard' and 'high' populations. Strikingly, this increase in reproductive success did not come at a cost to survival. Our results suggest that sustained DR selects for more robust male genotypes that are overall better in converting resources into energy, which they allocate mostly to reproduction.
authors.affiliation: School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia Department of Animal Ecology, Evolutionary Biology Centre, Uppsala University, Uppsala 75236, Sweden felix@zajitschek.net.
authors.forename: Felix
authors.identifier: http://orcid.org/0000-0001-6010-6112
authors.initials: F
authors.lastname: Zajitschek
authors.affiliation: Department of Evolutionary Biology, Evolutionary Biology Centre, Uppsala University, Uppsala 75236, Sweden Doñana Biological Station, Spanish Research Council CSIC, c/ Americo Vespucio, s/n, Isla de la Cartuja, 41092 Sevilla, Spain.
authors.forename: Susanne R K
authors.identifier: http://orcid.org/0000-0003-4676-9950
authors.initials: SR
authors.lastname: Zajitschek
authors.affiliation: Department of Animal Ecology, Evolutionary Biology Centre, Uppsala University, Uppsala 75236, Sweden.
authors.forename: Cindy
authors.initials: C
authors.lastname: Canton
authors.affiliation: Department of Animal Ecology, Evolutionary Biology Centre, Uppsala University, Uppsala 75236, Sweden.
authors.forename: Grigorios
authors.initials: G
authors.lastname: Georgolopoulos
authors.affiliation: Department of Evolutionary Biology, Evolutionary Biology Centre, Uppsala University, Uppsala 75236, Sweden IFM Biology, AVIAN Behavioural, Genomics and Physiology Group, Linköping University, Linköping 58183, Sweden.
authors.forename: Urban
authors.identifier: http://orcid.org/0000-0001-6112-9586
authors.initials: U
authors.lastname: Friberg
authors.affiliation: Department of Animal Ecology, Evolutionary Biology Centre, Uppsala University, Uppsala 75236, Sweden.
authors.forename: Alexei A
authors.initials: AA
authors.lastname: Maklakov
mesh_terms: D000818:Animals; D005075:Biological Evolution; D031204:Caloric Restriction; D004032:Diet; D004331:Drosophila melanogaster / Q000502:physiology*; D008136:Longevity; D008297:Male; D012098:Reproduction
keywords: Drosophila melanogaster; adaptation; dietary stress; nutrition