I am performing a spatio-temporal analysis of 652 viral samples but I have found information that as part of the process I should remove duplicate sequences prior an ML tree construction. However, I have not found information that support this procedure. Moreover, this will be a problem if we consider that we could remove identical samples but from different years and/or locations. As far as I understand, the main issue is associated with the computational cost while other reasons are related to technical problems of some programs to deal with duplicate sequences. Please, it would be really great to understand if this step is really necessary. Thanks!