A shift towards the annual habit in selfing Arabidopsis lyrata

The annual life history is often associated with the ability to self-fertilize. However, it is unknown which, of selfing or the annual habit, evolves first during the speciation process. Using a two-year common garden, we asked if the evolution of selfing in the normally perennial Arabidopsis lyrata was accompanied by a shift towards the annual habit. Despite their very recent divergence from obligately outcrossing populations, selfing plants exhibited a 39% decrease in over-winter survival after the first year as compared to outcrossing plants. Reproductive investment in the first year did not explain this difference in survival. We conclude that the evolutionary transition to selfing in perennial A. lyrata has been accompanied by a shift towards the annual habit. Because the shift does not appear to be due to reproductive trade-offs, its drivers require further investigation.