The evolutionary loss and regain of lipid synthesis
Evolution was long thought to be irreversible, where lost traits diminish genetic variation that pushes systems towards evolutionary dead-ends. Recent comparative work has challenged this view, showing that numerous lost traits have been regained over the course of evolution. We have yet to decipher how and when adaptive trait loss and regain occurs, an objective that is fraught with difficulties because ancestral and derived lineages often do not co-occur. Parasitoids have recently emerged as an exceptional model for studying reverse evolution in action, as these are the only animals to have lost and regained a key metabolic trait, lipid synthesis, both between and within species. Using a parasitoid species that shows intra-specific variability in lipogenic ability, we aim to study trait loss and reversion both in the laboratory and in the wild. This work will lead to critical insights into the mechanistic underpinnings of trait loss and reversal and will elucidate how these processes are currently taking place in the wild.