The Earth holds an immense tapestry of life that scientists are still working to fully understand and catalog. While roughly 1.9 million species are known today, estimates suggest the total number of species on the planet may be closer to 8.7 million. The scientific discipline dedicated to finding, describing, and naming these organisms is called taxonomy. The effort to systematically record all life is a continuous process that raises a fundamental question: how quickly is science adding to this ever-growing inventory?
Quantifying the Daily Discovery Rate
The pace at which science expands the catalog of life is measured by the number of new species descriptions published annually. Based on data from 2015 to 2020, researchers documented an average of more than 16,000 new species each year. This translates to a rate of approximately 44 new species being formally described every day. This figure is a working average that fluctuates based on funding and the complexity of the organisms studied.
It is important to distinguish between a species being “discovered” and being “described.” An organism may be collected years before it is formally recognized as new to science. The daily rate of 44 refers specifically to the number of species that move past the rigorous scientific validation process and receive a formal name through publication. This published rate is currently one of the highest in history, suggesting that the pace of description is accelerating rather than slowing down.
The Formal Process of Species Recognition
For a newly found organism to be accepted as a new species, it must undergo a meticulous, multi-step process known as a formal description. This process begins with the collection of one or more physical examples, which are designated as the type specimen. The type specimen serves as the permanent, physical reference for the new species and is typically deposited in a recognized natural history museum or collection.
A taxonomist must then conduct a thorough investigation, comparing the specimen’s physical features and genetic makeup to all known related species. This comparison often involves detailed morphological analysis and modern DNA sequencing to establish that the organism is biologically distinct.
The scientist summarizes these findings in a detailed manuscript, which includes the proposed Latin-based binomial name and a scientific diagnosis. The manuscript must then be published in a peer-reviewed scientific journal to validate the name and description. The naming process is governed by internationally agreed-upon standards, such as the International Code of Zoological Nomenclature (ICZN) for animals and the International Code of Nomenclature for algae, fungi, and plants (ICN). Once published, the new species is officially recognized and added to the global catalog of life.
Where New Life is Being Found
The majority of species currently being described are not large mammals or birds, but rather smaller, highly diverse, or cryptic organisms. The greatest proportion of new species consists of animals, particularly arthropods and insects, which accounted for more than 10,000 of the newly described species between 2015 and 2020. Fungi are another rapidly expanding group, with the number of known fungal species exceeding the combined total of all described vertebrates.
New species are being found among:
- Plants
- Arachnids
- Fishes
- Amphibians
Many of these discoveries stem from regions with high biodiversity that remain relatively under-explored. Tropical rainforests continue to be primary hotspots for new terrestrial life. Beyond land, the deep ocean, soil, and sediment samples are yielding numerous new species of marine invertebrates and microbes. Genetic analysis is increasingly revealing that what was once considered a single species is, in fact, several distinct, look-alike species, a phenomenon known as cryptic diversity.