Figure 2. Conceptual summary diagram.

A: comparison of general virus prediction strategies utilized by software tools, from variable recall and precision capabilities to a balanced approach. B: categorization of virus predictions as “not novel” or “novel” according to similarity to reference databases and datasets of uncultivated viral sequences. C: the reference-free fallacy; visualization of how virus prediction software tools, whether protein annotation-based (left) or nucleotide feature-based (right), are all inherently referenced-based. D: the fate of complete linear versus circular viral genomes in interpreting metagenomic data. E: illustration of a viral genome either binned into a vMAG (left) or analyzed as individual fragments (right); each sequence fragment is represented by puzzle pieces.