“We are really fairly ignorant of the complexity and colorfulness of this amazing planet,” said the study’s co-author, Boris Worm, a biology professor at Canada’s Dalhousie University. “We need to expose more people to those wonders. It really makes you feel differently about this place we inhabit.”
Biologists have long known that there’s more to Earth than it seems, estimating the number of species to be somewhere between 3 million and 100 million. Figuring out how much is difficult.
Worm and Camilo Mora of the University of Hawaii used complex mathematical models and the pace of discoveries of not only species, but of higher classifications such as family to come up with their estimate.
Their study published in the online journal PLoS Biology, a publication of the Public Library of Science, estimated the number of species at nearly 8.8 million.
Of those species, 6.5 million would be on land and 2.2 million in the ocean, which is a priority for the scientists doing the work since they are part of the Census of Marine Life, an international group of scientists trying to record all the life in the ocean.
The research estimates that animals rule with 7.8 million species, followed by fungi with 611,000 and plants with just shy of 300,000 species.
While some new species like the strange mini-lobster are in exotic places such as undersea vents, “many of these species that remain to be discovered can be found literally in our own backyards,” Mora said.
The study said it could be off by about 1.3 million species, with the number somewhere between 7.5 million and 10.1 million.
The study’s authors point to other species as evidence of the growing rate of discovery: the 6-inch, blind, hairy lobster-type species found in 2005 by a submarine looking at hydrothermal vents near where the Pacific meets Antarctica and a brilliant-colored frogfish found by divers in Indonesia in 2008.
Of the 1.9 million species found thus far, only about 1.2 million have been listed in the fledgling online Encyclopedia of Life, a massive international effort to chronicle every species that involves biologists, including Wilson.
If the 8.8 million estimate is correct, “those are brutal numbers,” said Encyclopedia of Life executive director Erick Mata. “We could spend the next 400 or 500 years trying to document the species that actually inhabit our planet.”