Biodiversity
How many species live on Earth and in the ocean?
Open access · cc by · source: Europe PMC
A validated taxonomic extrapolation estimates ~8.7 million eukaryotic species on Earth, with most still undescribed.
How this study connects
Role on claims
Each row is a claim on a concept or method page where this paper supports, challenges, or qualifies the statement. Roles are hand-checked — not a model guess.
Multiple empirical papers in this library examine biodiversity with mechanistic biological findings.
Evidence for the claim as stated.
They estimate ~8.7 million species overall, narrowing prior expert ranges of 3–100 million, and conclude only ~14% of Earth and ~9% of ocean species are catalogued after 250 years of taxonomy.
Evidence for the claim as stated.
Systems and scales differ across biodiversity studies (species, tissues, methods), so mechanisms should not be over-generalised.
Evidence for the claim as stated.
Open questions
Tensions this paper is part of
From concept pages' “where studies disagree.” Disagreement means the same question; scope means different assays, populations, or outcomes.
Systems and scales differ across biodiversity studies (species, tissues, methods), so mechanisms should not be over-generalised.
Discoveries this paper informs or conflicts with
- About 8.7 million species — and roughly seven in eight have never been described
This paper informs this development.
Study at a glance
- Design
- Computational / modelling — Higher-taxon discovery models extrapolating eukaryotic species richness, plus taxonomist survey
- N
- N=548 · 548 taxonomists responded of ~2,938 contacted (18.7%); species estimate ~8.7 million is model-based
- Population
- Global taxonomic catalogues and surveyed taxonomy experts
- Outcome
- Estimated number of eukaryotic species on Earth and in the ocean
Structured fields used in claim comparison tables when every cited study has a complete layer.
Inspect source passages
How many species live on Earth and in the ocean?
These passages occur verbatim in the stored paper text. They support the points listed below; they do not verify every statement in the explanation.
Estimate of ~8.7 million species on Earth.
Our current estimate of ∼8.7 million species narrows the range of 3 to 100 million species suggested by taxonomic experts and it suggests that after 250 years of taxonomic classification only a small fraction of species on Earth (∼14%) and in the ocean (∼9%) have been indexed in a central database ().
What fraction of Earth species are catalogued?
only a small fraction of species on Earth (∼14%) and in the ocean (∼9%) have been indexed in a central database ().
Key findings
They estimate ~8.7 million species overall, narrowing prior expert ranges of 3–100 million, and conclude only ~14% of Earth and ~9% of ocean species are catalogued after 250 years of taxonomy.
Methodology
Authors modeled higher-taxon discovery patterns to extrapolate species richness for Earth and ocean eukaryotes, validating against well-sampled groups and surveying taxonomists about synonyms and effort.
Limitations
Prokaryote diversity is poorly captured by the same species concept; estimates will shift with better synonym control and sampling.
Related papers in this topic
Same topic cluster — not a recommendation engine.