...to understand the functional and evolutionary history of cryptochrome magnetic sensitivity. Using the protein production pipeline and mutational strategies set up during the first funding period, this project will produce a variety of cryptochrome mutants from several different bird species. The magnetic sensitivity of these mutated proteins will be measured spectroscopically by our Mercator Fellows and collaborators in Oxford. Based on the insight from new protein mutants, spectroscopic measurements, theoretical predictions, and phylogenetic analyses, we will investigate why some cryptochromes are more magnetically sensitive than others.