Earth could contain nearly 1 trillion species, with only one-thousandth of 1 percent now identified, according to the results of a new study.
The estimate, based on universal scaling laws applied to large datasets, appears today in the journal Proceedings of the National Academy of Sciences. The report’s authors are Jay Lennon and Kenneth Locey of Indiana University in Bloomington, Indiana.
The scientists combined microbial, plant and animal datasets from government, academic and citizen science sources, resulting in the largest compilation of its kind.
Altogether, these data represent more than 5.6 million microscopic and non-microscopic species from 35,000 locations across all the world’s oceans and continents, except Antarctica.
Great challenge in biology
“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.”
He added that “until recently, we’ve lacked the tools to truly estimate the number of microbial species in the natural environment. The advent of new genetic sequencing technology provides a large pool of new information.”
The work is funded by the National Science Foundation (NSF) Dimensions of Biodiversity program, an effort to transform our understanding of the scope of life on Earth by filling major gaps in knowledge of the planet’s biodiversity.
“This research offers a view of the extensive diversity of microbes on Earth,” said Simon Malcomber, director of the Dimensions of Biodiversity program. “It also highlights how much of that diversity still remains to be discovered and described.”