00 · IN THREE MINUTES
The answer in three steps
- 1 continually removes some lineages.
- 2Mass extinctions are unusually large, widespread and rapid in geological terms.
- 3Fossil sampling is incomplete, so researchers compare multiple groups, regions and dating methods before naming an event.
01 · DEATH IS NOT EXTINCTION
Death is not extinction
An organism dies; a species becomes extinct when its final population disappears. A local ecosystem can collapse while the species survives elsewhere, so scale must be defined.
02 · BACKGROUND PROVIDES THE BASELINE
Background provides the baseline
Lineages originate and vanish throughout Earth history. Paleontologists estimate background turnover for intervals and taxonomic groups before judging whether a pulse is exceptional.
03 · THE BIG FIVE CROSS MANY GROUPS
The Big Five cross many groups
Five Phanerozoic intervals show particularly severe global marine losses and broad ecological disruption. Causes differ, including volcanism, climate change, ocean chemistry and asteroid impact.
Death is not extinction
An organism dies; a species becomes extinct when its final population disappears. A local ecosystem can collapse while the species survives elsewhere, so scale must be defined.
background rateBackground provides the baseline
Lineages originate and vanish throughout Earth history. Paleontologists estimate background turnover for intervals and taxonomic groups before judging whether a pulse is exceptional.
global pulseThe Big Five cross many groups
Five Phanerozoic intervals show particularly severe global marine losses and broad ecological disruption. Causes differ, including volcanism, climate change, ocean chemistry and asteroid impact.
fossil filterThe rock record filters the signal
Hard-bodied marine organisms preserve better than many terrestrial or soft-bodied species. Uneven sampling and dating can spread or sharpen an apparent pulse, so statistical correction matters.
ecological reset04 · THE ROCK RECORD FILTERS THE SIGNAL
The rock record filters the signal
Hard-bodied marine organisms preserve better than many terrestrial or soft-bodied species. Uneven sampling and dating can spread or sharpen an apparent pulse, so statistical correction matters.
Background extinction continually removes some lineages.
Current losses and threat levels are severe, but estimates depend on unknown species counts, time windows and future trajectories. The warning does not require pretending the modern record is identical to a finished fossil interval.
05 · RECOVERY CREATES A NEW WORLD
Recovery creates a new world
Ecological roles and diversity can take millions of years to rebuild. Survivors diversify into emptied niches, meaning recovery does not restore the previous ecosystem exactly.
06 · SOURCES AND EVIDENCE
Sources and evidence
The explanation follows the evidence chain below. Links open the original source.
- 01What is mass extinction?INSTITUTIONAL EXPLAINER ↗
Supports a specific claim or evidence boundary used in this article.
- 02Global Assessment Report on BiodiversityOFFICIAL DATA / TECHNICAL REPORT ↗
Supports a specific claim or evidence boundary used in this article.
- 03Phanerozoic biodiversity mass extinctionsPEER-REVIEWED REVIEW ↗
Supports a specific claim or evidence boundary used in this article.