Sequencing DNA of museum specimens to uncover the genetic basis of rapid adaptation to heavy fishing.

We currently lack a detailed understanding of how organisms rapidly adapt genetically to environmental changes. However, gaining such an understanding is key in evaluating and predicting human impact on nature, can uncover the genetic basis of adaptive traits, and give insight into fundamental evolutionary processes. To address this, we will dissect the genetic factors contributing to rapid adaptation in Lake Malawi cichlid fish populations following ~40 years of extremely heavy fishing. We have already collected and whole-genome sequenced 96 samples from present day weakly and heavily fished populations. Analysis of these samples suggested overall very close relatedness between populations, but identified the presence of candidate genomic regions of high genetic divergence between weakly and heavily fished populations. Here we suggest to sequence the genomes of museum specimens (an innovative technique sometimes referred to as "museomics") from the same populations before the onset of heavy fishing and during fishing. Samples are available through established collaborations with the British Museum of Natural History, the Monkey Bay Fisheries Research Station in Malawi, and Prof. Erik Verheyen (University of Antwerp and Royal Belgian Institute of Natural Sciences). Comparing the genetic composition of historic populations with the present-day genetic composition (after 40 years of heavy fishing) will enable us to identify candidate genes conferring adaptation to fishing. We have performed a pilot study, which suggests that the museum specimens used in this study yield sufficient DNA for genome sequencing. We also have recently established breeding colonies of the same fish populations at the University of Antwerp, which will allow us in future projects to follow up phenotypic changes related to the genetic adaptations identified here. This project will yield important data and results to support an ERC starting grant application by the applicant on this study system that aims to dissect the links between genotypes, phenotypes and selective pressures in rapid human-induced evolution.

Keywords:GENOMICS, FISHERIES-INDUCED EVOLUTION, MUSEOMICS, EVOLUTIONARY GENETICS

Disciplines:Biology of adaptation, Population, ecological and evolutionary genetics