"Except you know what’s weird? Although the absolute diversity of prokaryotes is widely held to be unknown and unknowable at any scale, most new genetic information we find in bacteria is similar to genetic information we’ve seen elsewhere. It’s a comforting reminder that, although large-grain diversity is uncountably large, most genes in diverse bacteria have sequence-based similarity. But when you sequence a sample of mixed viruses, most of that genetic information has never been seen before, anywhere. "