Without getting too deep into discussion of this particular paper - viruses aren't even considered to be "living organisms" per se and don't really fit into the

Without getting too deep into discussion of this particular paper - viruses aren't even considered to be "living organisms" per se and don't really fit into the biological taxonomy. Their own taxonomy is rather vague and uses classification methods different from those applied to living organisms. As far as the paper is concerned - divergence in virus populations based on their affinity for a specific receptor is nothing new, the very well researched influenza virus has been shown to do the exact same thing.