Anthropogenic Parasite Evolution

Informations

Funding country

Norway

Acronym

-

URL

-

Start date

1/1/2019

End date

12/31/2027

Budget

1,217,085 EUR

Fundings

Abstract

In the past decade we have had increasing insight into the way humans with their activities modify selection on wild plants and animals - and how this will affect their evolutionary trajectories. Parasites (including pathogens) are organisms present in all branches of the tree of life, and that owe their success to the fact that they live and feed from other living organisms. We all know them because they cause infectious disease; what may be less known is that they represent the majority of all living species and are essential to ecosystem functioning, stability, and diversity. Yet despite their importance we still understand poorly how human activities affect them and drive their evolution. This question has mostly been addressed theoretically, as it is notoriously difficult to study parasites in animal populations due to the difficulty in tracking parasites and estimating their reproductive success. Human activities are changing the environment for parasites, both indirectly by changing the living conditions for their plant and animal hosts, and directly via drugs and vaccines that target them. One major human activity combining these two types of effects is modern farming. Humans and their domestic animals vastly dominate the biosphere in biomass and abundance, and for their parasites this represents a huge and global ecological change, which long-term evolutionary consequences remain largely unknown. To understand the human evolutionary impact on parasites, we first need to understand the mechanisms of parasite adaptation, and in particular how environmental changes translate into selection on parasites. The aim of this project is to gain insight into these questions, using the salmon louse as a model species. We have developed a unique mark-recapture approach that has allowed us to monitor populations of this parasite as they were evolving under various scenarii. The data that we are collecting spans over 10 generations of parasites and will allow us to characterise the selection acting in these populations and test theoretical predictions about their evolution in dense, as compared to sparse, populations. This will significantly advance current knowledge on how the interactions between parasites and their hosts are affected by the changes imposed by humans on populations. One key aspect of these changes is that plant and animal populations are either rapidly declining or increasing in abundance. The knowledge generated by this project will improve our ability to tackle the current biodiversity crisis and its future consequences.