sentence: Ochmann and co-workers found that poorly connected proteins are more likely to be lost in the evolution of γ - proteobacteria [ 45 ] , while Tamanes and co-workers found that in the reductive evolution of Buchnera aphidicola APS , gene loss did not correlate with the absolute number of links of a protein in the protein interaction network ( some hubs were more likely to be preserved than others ) , nor did they observe any drive to keep functional modules intact [ 46 ] .