Tuesday, May 3, 2016 4:31 pm
A United States study said on Tuesday in Washington that the earth could be home to nearly one trillion species, with only one-thousand of 1 per cent now identifie, meaning 99.9 percent unidentified.
Scientists said the estimate, published in the U.S. Journal Proceedings of the National Academy of Sciences, was based on data representing more than 5.6 million microscopic and non-microscopic species from 35,000 locations across all the world’s oceans and continents, except Antarctica.
Jay Lennon, Lead Author and Associate Professor at the Indiana University, said in a statement that estimating the number of species on Earth is among the great challenges in biology.
He said the group study combined 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.”
Lennon said his earlier attempts, simply ignored microorganisms or was informed by older datasets that were based on biased techniques or questionable extrapolations.
“The realisation that microorganisms were significantly under-sampled caused an explosion in new microbial sampling efforts over the past several years.
Lennon said the efforts included the collection of human-related microorganisms by the U.S. National Institutes of Health’s Human Microbiome Project, marine microorganisms by the Tara Oceans Expedition and aquatic, terrestrial and host-related microorganisms by the Earth Microbiome Project.
He said the data sources and many others were compiled to create the inventory in the new study, which pulled together 20,376 sampling efforts on bacteria, archaea and microscopic fungi and 14,862 sampling efforts on communities of trees, birds and mammals.
The associate professor said the study results also suggested that actually identifying every microbial species on Earth is an almost unimaginably huge challenge.
Lennon said the Earth Microbiome Project, is a global multidisciplinary project to identify microscope organisms, and has so far catalogued less than 10 million species.
“Of those catalogued species, only about 10,000 have ever been grown in a lab, and fewer than 100,000 have classified sequences.
“Our results show that this leaves 100,000 times more microorganisms awaiting discovery and 100 million to be fully explored,’’ he said.
Lennon said microbial biodiversity, is greater than ever imagined.