When attempting to understand evolution, we traditionally rely on analysing evolutionary outcomes, despite the fact that unseen intermediates determine its course. A handful of recent studies has begun to explore these intermediate evolutionary forms, which can be reconstructed in the laboratory. With this first view on empirical evolutionary landscapes, we can now finally start asking why particular evolutionary paths are taken.


Poelwijk, F., Kiviet, D. J., Weinreich, D. M., & Tans, S. (2007). Empirical fitness landscapes reveal accessible evolutionary paths. Nature, 445, 383–386. doi:10.1038/nature05451