* Progression occurs through a variety of pathways.<ref name="livestream-19-May-2017-51:52">[https://youtu.be/LUJugtqTBxw?t=51m52s Livestream, 19 May 2017 (51:52)]</ref> | * Progression occurs through a variety of pathways.<ref name="livestream-19-May-2017-51:52">[https://youtu.be/LUJugtqTBxw?t=51m52s Livestream, 19 May 2017 (51:52)]</ref> |