The Fastest Rate Of New Species Discovery In History Just Happened. Here’s What Scientists Are Finding

New Study: We’re Discovering Species Faster Now Than in the ‘Golden Age’ of Exploration

Scientists are discovering and naming new species at record-breaking speeds, shattering long-held assumptions that the golden age of biodiversity discovery peaked more than a century ago. A comprehensive analysis reveals that 2020 saw more new species formally described than any other year in recorded history, with recent rates showing no signs of slowing down.

These findings track species that scientists have formally described and named in scientific literature. It’s a crucial step for conservation, since species can’t be protected until they’re documented. The actual number of species on Earth is likely far higher, but this study examines how quickly researchers are cataloging the biodiversity they encounter.

The paper, published in Science Advances, contradicts influential research from the early 2010s suggesting that species description rates maxed out around 1900 and had been declining ever since. Instead, researchers examining data from nearly 2 million known species found that the fastest rates all occurred within the past two decades. From 2015 through 2020, scientists described more than 16,000 new species annually, with 2020’s total reaching 17,044 species, the highest count since systematic naming began in the 1750s.

The research team tracked species descriptions across all living organisms, excluding viruses, and found that overall discovery rates have been accelerating at the decadal scale rather than declining. The analysis challenges the notion that most of Earth’s species have already been found.

Species Discovery Rates Accelerate for Earth’s Most Diverse Groups

The analysis revealed that organisms with the most species are also growing their known diversity most rapidly. Animals, arthropods (insects, spiders, crustaceans), beetles, and ray-finned fishes all dominated recent new species descriptions. Between 2000 and 2020, these groups accumulated substantial numbers of new species—with 17% of all currently known animal species described during just these two decades.

Beetles accounted for thousands of newly described species per year during this period. Arthropods saw similar patterns, with 16% of their current diversity described since 2000. Ray-finned fishes, already the most diverse vertebrate group, had 21% of their current species described in the past two decades.

Fungi showed particularly dramatic acceleration in recent years, with scientists now naming thousands of new fungal species annually. Plants maintained relatively steady rates for more than a century but have increased notably over the past several decades, with 15% of current plant diversity described since 2000. Even bacteria and archaea, microscopic organisms notoriously difficult to classify, showed dramatically accelerating description rates.

Historical Data Reveals Unexpected Patterns in Biodiversity Documentation

Previous research suggested peak rates occurred near 1900, but that conclusion relied on incomplete taxonomic coverage and data that ended around the year 2000. The new analysis, using more comprehensive databases and extending through 2020, shows that rates around 1900 were indeed high but didn’t exceed recent totals until after 2008.

Some groups did peak historically. Insects as a whole, along with major orders like flies, wasps, and butterflies and moths, had their fastest description rates around 1910. These groups showed sharp declines during both World Wars before recovering, leaving visible scars in the biodiversity discovery timeline.

Spiders and mites, crabs and shrimp, ray-finned fishes, amphibians, and lizards and snakes all showed consistently increasing rates over time, with their highest numbers appearing in the 2000s and 2010s. Mollusks, the second-largest animal group after arthropods, demonstrated increasing rates over the past century with a strong peak in the 21st century. Among kingdoms of life, fungi, bacteria, and archaea all hit their fastest rates within the past 20 years.

Patterns Suggest Multiple Contributing Factors

The study documents these accelerating rates but stops short of definitively explaining why they’re occurring. Several factors could potentially play a role. Technological advances, particularly DNA sequencing, may make it easier to distinguish species that look similar but are genetically distinct. International collaboration has expanded, potentially improving access to biodiversity hotspots. Digital databases and online publishing have changed how descriptions are shared and cataloged.

The number of researchers studying biodiversity has also grown, though whether this represents increased effort or simply reflects broader trends in scientific collaboration remains debated. Some earlier analyses suggested that increasing numbers of authors per species description indicated dwindling pools of undiscovered species, while more recent studies argue this pattern appears across all scientific fields.

Certain groups show particularly striking recent acceleration. Fungi descriptions took off in recent decades, possibly linked to molecular techniques that can identify species from environmental samples. Some marine organisms like certain crustacean and fish groups showed increasing rates in recent years. Amphibians and reptiles from tropical regions accumulated many new descriptions, potentially reflecting focused survey efforts.

World Wars I and II caused severe disruptions visible in the data as sharp drops in species descriptions. After World War I ended, rates rebounded strongly through the 1920s and 1930s, only to plummet again during World War II. Recovery took longer after the second war, with rates not returning to pre-war levels until the 1960s for many groups.

Future Projections Suggest Millions More Species Await Discovery

Based on current description rates and historical patterns, researchers projected future biodiversity numbers extending to the year 2400. Their conservative model-based approach suggests several groups will see dramatic increases in known species numbers.

Fungi could reach approximately 307,000 described species, more than double their current 142,000. Plants might climb from 363,000 to 532,000 species. Arachnids could balloon from 91,000 to 752,000 species, an eightfold increase driven by mites and spiders. Malacostracan crustaceans might expand from 42,000 to 353,000 species.

Ray-finned fishes show particularly striking projections, potentially growing from 33,500 current species to over 114,000. Amphibians could increase more than fivefold, from roughly 8,000 to 41,000 species. Sharks and rays might expand from 1,260 to 7,763 species.

The overall animal kingdom might contain around 2.6 million described species by 2400, compared to 1.3 million today. Arthropods could reach 2 million species, while insects specifically might total 1.4 million. These projections carry considerable uncertainty and assume current patterns will continue, which may not account for technological changes, funding shifts, or extinction impacts.

Conservation Implications of Accelerating Species Discovery Rates

The analysis points to a clear challenge: species cannot be protected until scientists formally describe and name them. Recent studies suggest that more recently described species face higher extinction risks than those documented long ago, creating urgency around discovery pace as habitat loss and climate change accelerate extinction rates.

Current extinction documentation remains limited, with only about 900 species officially recorded as extinct over the past 500 years. These numbers likely represent severe underestimates due to “dark extinctions”—species that disappeared before scientists could describe them. The faster discovery rates documented in this research offer hope that more biodiversity can be catalogued before it vanishes.

Yet major gaps remain. For insects alone, many estimates place total diversity around 6 million species, far exceeding the 1.4 million projected to be described by 2400 at current rates. Fungi might number 6 million species or more, yet current description rates would require hundreds of years to document even the conservative projection of 307,000.

Plants showed accelerating description rates over the past several decades. Current plant diversity already exceeds some earlier projections that suggested only 10 to 20 percent more species remained to be found.

The researchers emphasize that their projections focus only on formally described species, not actual biodiversity. True species numbers might be considerably larger. Groups like protists may number in the millions but have only about 64,000 described species. Bacteria estimates range from millions to trillions, yet researchers projected only around 87,000 described species by 2400 at current rates.

These discrepancies highlight immense work ahead and suggest that traditional description methods may need supplementation. New approaches for cataloging diversity, such as DNA barcoding initiatives and automated identification systems, could help close the gap. For microscopic organisms, alternative frameworks like the Genome Taxonomy Database for prokaryotes may prove necessary.

The analysis tracked species descriptions using the Catalogue of Life database along with validation from other sources. Approximately 2 percent of species in the database lacked clear publication dates and were excluded. The researchers accounted for potential delays between when species are formally described and when they appear in databases by excluding data from 2021 through 2024.