BLOOMINGTON, Ind. — Earth could contain nearly 1 trillion species, with only one-thousandth of 1 percent now identified, according to a study from biologists at Indiana University.
The estimate, based on the intersection of large datasets and universal scaling laws, appears today in the Proceedings of the National Academy of Sciences. The study’s authors are Jay T. Lennon, associate professor in the IU Bloomington College of Arts and Sciences’ Department of Biology, and Kenneth J. Locey, a postdoctoral fellow in the department.
The IU scientists combined microbial, plant and animal community datasets from government, academic and citizen science sources, resulting in the largest compilation of its kind. Altogether, these data represent over 5.6 million microscopic and nonmicroscopic species from 35,000 locations across all the world’s oceans and continents, except Antarctica.
“Estimating the number of species on Earth is among the great challenges in biology,” Lennon said. “Our study combines the largest available datasets with ecological models and new ecological rules for how biodiversity relates to abundance. This gave us a new and rigorous estimate for the number of microbial species on Earth.
“Until recently, we’ve lacked the tools to truly estimate the number of microbial species in the natural environment,” he added. “The advent of new genetic sequencing technology provides an unprecedentedly large pool of new information.”