We are living in a golden age of species discovery
Roughly three centuries ago, Swedish naturalist Carl Linnaeus set out to catalog and name every living organism he could
Roughly three centuries ago, Swedish naturalist Carl Linnaeus set out to catalog and name every living organism he could find. He is now widely regarded as the founder of modern taxonomy after introducing the binomial naming system and formally describing more than 10,000 species of plants and animals. Scientists have continued that mission ever since, steadily expanding humanity’s understanding of Earth’s biodiversity.
A new study led by researchers at the University of Arizona and published in Science Advances shows that the pace of discovery is accelerating. Today, scientists are identifying more than 16,000 new species each year, the highest rate ever recorded. The researchers say this trend is not slowing and suggest that groups such as plants, fungi, arachnids, fishes and amphibians are far more diverse than previously believed.
“Some scientists have suggested that the pace of new species descriptions has slowed down and that this indicates that we are running out of new species to discover, but our results show the opposite,” said John Wiens, a professor in the University of Arizona Department of Ecology and Evolutionary Biology, in the College of Science, and senior author of the paper. “In fact, we’re finding new species at a faster rate than ever before.”
What the Data Reveal About Global Biodiversity
To reach their conclusions, the team examined the taxonomic records of roughly 2 million species from across all major forms of life. Looking at the most recent period with comprehensive data, between 2015 and 2020, they found that researchers documented an average of more than 16,000 new species per year. These discoveries included more than 10,000 animals (dominated by arthropods and insects), about 2,500 plants, and roughly 2,000 fungi.
“Our good news is that this rate of new species discovery far outpaces the rate of species extinctions, which we calculated to about 10 per year,” said Wiens, referring to another study he led that was published in October. “These thousands of newly found species each year are not just microscopic organisms, but include insects, plants, fungi and even hundreds of new vertebrates.”
More Species Than Ever and Many Still Undiscovered
Wiens and his co-authors found that scientists are describing more species annually than at any other time in history. They also used long-term trends in discovery rates to estimate how many species may exist overall. Their projections suggest there could be as many as 115,000 fish species and 41,000 amphibian species, compared with about 42,000 fish and 9,000 amphibians currently described. The researchers also estimate that the total number of plant species could exceed half a million.
“As the famous ecologist Robert May said, if visiting aliens asked us how many species live on our planet, we would have no definitive answer,” said Wiens. “Right now, we know of about 2.5 million species, but the true number may be in the tens or hundreds of millions or even the low billions.”
The team expects the discovery rate to keep rising. For instance, scientists have formally identified around 1.1 million insect species, but many researchers estimate the real number is closer to 6 million. In earlier work, Wiens suggested the total could even approach 20 million.
“Right now, most new species are identified by visible traits,” said Wiens. He explained that advances in molecular techniques are making it possible to detect species that look similar on the surface but differ genetically. This approach is especially promising for uncovering previously unrecognized bacteria and fungi.
Why Discovering New Species Matters
“Discovering new species is important because these species can’t be protected until they’re scientifically described,” Wiens added. “Documentation is the first step in conservation — we can’t safeguard a species from extinction if we don’t know it exists.”
New discoveries also play a role in improving human health and technology. Many natural products come from living organisms, including GLP-1 receptor agonists, popular weight-loss drugs inspired by a hormone found in Gila monsters. Compounds from spider and snake venoms, along with substances produced by plants and fungi, are being studied for their potential to treat pain, cancer, and other conditions.
Beyond medicine, nature often inspires innovation. Some species have physical traits that serve as models for new materials and technologies, such as surfaces designed to mimic the “super-clinging” feet that allow geckos to scale vertical walls.
“We’re still just scratching the surface of what these species can do for humanity,” Wiens said.
Mapping the Future of Discovery
Looking ahead, the researchers plan to chart where new species are most frequently found to pinpoint regions rich in undiscovered life. They are also examining who is making these discoveries to see whether the field has shifted from being dominated by European scientists to researchers documenting species in their own home countries.
“Even though Linnaeus’ quest to identify species began 300 years ago, 15% of all known species have been discovered in just the past 20 years,” Wiens said. “So much remains unknown, and each new discovery brings us closer to understanding and protecting the incredible biodiversity of life on our planet.”
