The
A/Influenza/Goose/Guandong/1996 (Acc. No. F148678) was applied
as the root for all phylogenetic analyses. Screening of
positively and negatively selected sites was conducted using the
Single-Likelihood Ancestor Counting method (Pond and Frost,
2005), and evidence of episodic diversifying selection was traced
using the Mixed Effects Model of Evolution (Murrell et al., 2012).
All analyses were performed using the Datamonkey webserver and
the HyPhy package (Delport et al., 2010; Pond and Frost, 2005;
Pond et al., 2005).