title: Ancestral population reconstitution from isofemale lines as a tool for experimental evolution.
abstract: Experimental evolution is a powerful tool to study adaptation under controlled conditions. Laboratory natural selection experiments mimic adaptation in the wild with better-adapted genotypes having more offspring. Because the selected traits are frequently not known, adaptation is typically measured as fitness increase by comparing evolved populations against an unselected reference population maintained in a laboratory environment. With adaptation to the laboratory conditions and genetic drift, however, it is not clear to what extent such comparisons provide unbiased estimates of adaptation. Alternatively, ancestral variation could be preserved in isofemale lines that can be combined to reconstitute the ancestral population. Here, we assess the impact of selection on alleles segregating in newly establishedDrosophilaisofemale lines. We reconstituted two populations from isofemale lines and compared them to two original ancestral populations (AP) founded from the same lines shortly after collection. No significant allele frequency changes could be detected between both AP and simulations showed that drift had a low impact compared to Pool-Seq-associated sampling effects. We conclude that laboratory selection on segregating variation in isofemale lines is too weak to have detectable effects, which validates ancestral population reconstitution from isofemale lines as an unbiased approach for measuring adaptation in evolved populations.
authors.affiliation: Institut für Populationsgenetik Vetmeduni Vienna Vienna Austria.
authors.forename: Pierre
authors.initials: P
authors.lastname: Nouhaud
authors.affiliation: Institut für Populationsgenetik Vetmeduni Vienna Vienna Austria; Present address: Ray Tobler, Australian Centre for Ancient DNA School of Biological Sciences University of Adelaide Adelaide SA Australia.
authors.forename: Ray
authors.initials: R
authors.lastname: Tobler
authors.affiliation: Institut für Populationsgenetik Vetmeduni Vienna Vienna Austria.
authors.forename: Viola
authors.initials: V
authors.lastname: Nolte
authors.affiliation: Institut für Populationsgenetik Vetmeduni Vienna Vienna Austria.
authors.forename: Christian
authors.initials: C
authors.lastname: Schlötterer
keywords: Adaptation; evolve and resequence; experimental evolution; isofemale line; whole‐genome sequencing