There are half as many microbes as we once thought, but they still outnumber us. By a lot. Like, a lot a lot.S

Newly published research by microbiologists at the University of Potsdam in Germany has revealed that previous studies have vastly overestimated the number of microbes living at the bottom of the world's oceans.

"The new calculations [published in this week's issue of PNAS] decrease previous estimates by 92%," writes Nature News' Kathryn Lougheed, "and reduce the estimated numbers of all microbes on Earth by around 50%, to between 9.2×1029 and 31.7×1029."

According to researcher Jens Kallmeyer, first author on the newly published study, previous overestimates probably resulted from collecting samples in nutrient-rich coastal upwelling zones. Be that as it may, he says, "their still gigantic number means that they play a key role in global biogeochemical cycles".

[PNAS via Nature News]