A Study of Ecological Biodiversity Predicts the Existence of 1 Trillion Species on Earth

Ecological biodiversity on earth. Image source: Emaze

Ecological Biodiversity is an important aspect of ecological research. It is significant since every species has its own role in boosting natural sustainability for all the living entities.

Scientists from the Indiana University believe that Earth may be home to 1 trillion species. Incidentally, of which only 0.001% are known.

The study published in the Proceedings of the National Academy of Sciences is based on the intersection of large data sets and universal scaling laws. Scientists did the biggest compilation of the data of over 5.6 million microscopic and non-microscopic species.

These species were found to be residing in the oceans and continents worldwide excluding Antarctica. Consequently, the data was obtained from the microbial, plant, and animal community datasets of the government, academic, and citizen science sources.

The study provided a thorough estimation of microbial biodiversity on Earth,” says Jay T. Lennon, one of the authors and associate professor in the Bloomington College of Arts and Sciences, Indiana University.

This research offers a view of the extensive diversity of microbes on Earth,” said Simon Malcomber, director of the National Science Foundation’s Dimensions of Biodiversity Program. He further adds, “It also highlights how much of that diversity still remains to be discovered and described.


According to Lennon, previous studies estimating the ecological diversity on Earth mostly excluded microbial species, including unicellular organisms. Some studies were based on the old datasets which are biased in estimating the whole range of microorganisms due to lack of sufficient sampling.

However, in order to overcome the biases associated with old datasets, several new projects were floated. Furthermore, the major ones to born out of this were; human-related microorganisms by the 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.

The advancement in high throughput sequencing and bioinformatics has made it possible for the researchers to effectively estimate billions of microorganisms residing on Earth.

The present study compiled the data from these sources together with many other publicly available sources. Roughly put these comprise 20,376 sites of bacterial, archaeal, and microscopic fungal communities and 14,862 sites of tree, bird, and mammal communities.

The primary focus of the study was taxonomic characterization of biodiversity including species richness, evenness, rarity, and absolute dominance.


Scaling laws of predicting biodiversity is a measure of how physiological, ecological, and evolutionary constraints hold across the diverse range of micro and macro-organisms.

Scientists of this study revealed a universal dominance scaling law that predicts the abundance of dominant ocean bacteria. Furthermore, using the log normal model of diversity along with the scaling law, they predict that Earth may contain 1 trillion species.

Biodiversity on earth
Biodiversity on Earth could surpass 1 trillion mark. Image source: Shutterstock

However, the study also depicts that identification of each and every microorganism residing on Earth is next to impossible, as evidenced from the Earth Microbiome Project. The project was a huge collaborative approach to characterize microbial life on Earth. However, it has indexed less than 10 million species till now.

Of those cataloged species, only about 10,000 have ever been grown in a lab, and fewer than 100,000 have classified sequences,” Lennon said. “Our results show that this leaves 100,000 times more microorganisms awaiting discovery — and 100 million to be fully explored. Microbial biodiversity, it appears, is greater than ever imagined.

Wow!! 1 trillion species. Our school textbooks need to be rewritten.

Source Indiana University

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