Reply to “The Underestimation of Global Microbial Diversity”

Our commentary “After All, Only Millions?” (1) highlighted that, in contrast to a recent scaling law-based estimate of global microbial diversity of a trillion species-level operational taxonomic units (2), the decreasing frequencies of novel 16S rRNA gene sequences recovered by high-throughput sequencing (3, 4) is suggesting that global microbial diversity might well be saturated at a few million. No one knows even the order of magnitude of Bacteria and Archaea species numbers that ongoing surveys will …