HAS FISHERIES SELECTION AFFECTED THE RECOVERY AND ADAPTIVE POTENTIAL OF EXPLOITED FISH POPULATIONS?
The genetic basis of adaptation and adaptive potential is a fundamental and timely question in evolutionary biology. Habitat fragmentation, pollution, overexploitation and climate change are examples of human activities that can affect the adaptive potential of a species. This project uses fisheries as an example of human activity affecting populations’ adaptive potential.
Fisheries remove enormous amounts of fish from the ecosystem and typically target the largest individuals in a stock, thus generate strong directional selection. After certain amount of time, fisheries have reduced the population size and average individual body size to a level, where fishing is no longer profitable. At this point, fishing is typically stopped and populations are allowed to recover. IFan exploited population shows a sign of recovery, closed fisheries tend to be reopened, although it is not certain whether the population is resilient enough to any level of exploitation. The past fisheries selection has likely reduced phenotypic and genetic variation, thus eroded adaptive potential. The project utilizes experimentally harvested and recovered zebrafish (Danio rerio) populations to study the effects of harvesting on adaptive potential and whether these changes have reversed during the recovery. We will expose the recovered populations to re-harvesting and to an environmental stressor to see whether the recovered populations are resilient to new selection pressures.
The main questions of this project are:
- What is the recovery rate of the exploited fish populations at phenotypic (body size, growth rate, reproductive success) and genetic level (sequence and epigenetic)?
- How has the past selection affected the adaptive potential of the exploited fish populations? This question will be addressed by studying how resilient the recovered populations are to a) new selection pressures (e.g. thermal stress) and b) re-harvesting.
We are looking for a candidate who is highly motivated and has a background in evolutionary biology (Master’s degree in biology or related area). The candidate should have good statistical skills and preferably be familiar working with R and Unix. Experience in genetic lab work is a benefit. We will provide training in animal husbandry, experimental evolution, genetics/genomics, bioinformatics and statistics. Working language is English. The project is supervised by Dr. Silva Uusi-Heikkilä and Prof. Phillip Watts.
Further information: Academy Research Fellow Silva Uusi-Heikkilä, Email firstname.lastname@example.org
Uusi-Heikkilä S et al. (2015) The evolutionary legacy of size-selective harvesting extends from genes to populations. Evolutionary Applications 8, 597-620.
Uusi-Heikkilä S et al. (2017) Rapid, broad-scale gene expression evolution in experimentally harvested fish populations. Molecular Ecology 26, 3954-3967.