Humanity shares the planet with roughly 8.7 million species, most of them still undiscovered, according to a new study. Researchers used complex mathematical models to tackle a question that has long puzzled scientists, identifying numerical patterns in data from 1.2 million known species, excluding viruses and microorganisms, reports the Washington Post. Previous estimates ranged from 3 million to 100 million species. Some 86% of terrestrial species and 91% of marine species are still unknown, the researchers believe.
The researchers compare the planet to a machine with 8.7 million parts, each performing an important function. "If you think of the planet as a life-support system for our species, you want to look at how complex that life-support system is,” says one of the study's co-authors. “We’re tinkering with that machine because we’re throwing out parts all the time." The research, he says, shows that we are "really fairly ignorant of the complexity and colorfulness of this amazing planet. We need to expose more people to those wonders. It really makes you feel differently about this place we inhabit." (Read more species stories.)