Evolution on repeat: unravelling the developmental origins of parallel evolution

The diversity of life may seem endless. Yet, a closer look reveals that evolution often is on repeat. This is most striking when the same suite of characters evolves over and over.

One explanation for such parallel evolution is that development produces some phenotypes readily and frequently, while others are rare or impossible. I have identified an opportunity to put the role of development in parallel evolution to the test.

At least six species of wall lizards have repeatedly evolved a complex syndrome, including striking coloration, stout bodies, large heads, and aggressive behaviour. All these traits share an origin in the same cell type, neural crest cells.

I propose that this developmental coupling allows seemingly unrelated traits – colours, morphologies and behaviours – to vary together. As a result, variation is channelled down particular routes, resulting in parallel evolution.

This project will (1) unravel the genomic underpinnings of parallel evolution, and (2) test if independent origins of the syndrome share the same epigenetic and transcriptional modifications of neural crest cells. Failure to attend to the Arrival of the fittest has left us poorly equipped to predict evolutionary outcomes.

My research will fill this explanatory gap by showing that it is possible to understand the rules by which individuals vary, and use this insight to explain why evolution proceeds some ways rather than others.