Extinction Magnitude Percent Taxa

Compare distinct before/after observed taxa with comparable detection, separating lost/surviving/new records; absent observations do not themselves establish biological extinction.

Description

A before-and-after taxon comparison separates persistence, disappearance and new observations.

A before-and-after taxon comparison separates persistence, disappearance and new observations. Detection must be comparable before absence can be interpreted.

Compare distinct before/after observed taxa with comparable detection, separating lost/surviving/new records; absent observations do not themselves establish biological extinction.

When to use Extinction Magnitude Percent Taxa

Use this tool to compare distinct before/after observed taxa with comparable detection, separating lost/surviving/new records; absent observations do not themselves establish biological extinction.

Prepare the fossil measurements or occurrence records and the chosen calibration parameters. Retain the stated coordinate, age and measurement conventions.

How to use Extinction Magnitude Percent Taxa and understand its results

Prepare the fossil measurements or occurrence records and the chosen calibration parameters. Retain the stated coordinate, age and measurement conventions.
Enter preEventTaxonIds, postEventTaxonIds, comparableDetection using the field table and calculation rules, then run the tool.
Read observedLostTaxaCount, observedSurvivingTaxaCount, observedLostPreEventTaxaPercent, newlyObservedTaxaCount. The explanation below defines the units, signs, ordering and any flags or placeholder values.
If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.

Input field	Meaning	Value type; see rules below	Requirement
preEventTaxonIds	Pre event taxon ids	list of number	Required
postEventTaxonIds	Post event taxon ids	list of number	Required
comparableDetection	Comparable detection	boolean	Required

Use 1–128 unique nonnegative integer pre-event IDs and zero through 128 distinct post-event IDs. Explicitly accept comparable detection; otherwise input errors. Return lost, surviving and newly observed counts.^[1]

lost percent = 100 × pre-event taxa absent afterward/pre-event taxa

Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.

Output field	Meaning	Value type
observedLostTaxaCount	Observed lost taxa count	number
observedSurvivingTaxaCount	Observed surviving taxa count	number
observedLostPreEventTaxaPercent	Observed lost pre event taxa percent	number
newlyObservedTaxaCount	Newly observed taxa count	number

json

{
  "input": {
    "preEventTaxonIds": [
      1,
      2,
      3,
      4
    ],
    "postEventTaxonIds": [
      2,
      3,
      5
    ],
    "comparableDetection": true
  },
  "output": {
    "observedLostTaxaCount": 2,
    "observedSurvivingTaxaCount": 2,
    "observedLostPreEventTaxaPercent": 50,
    "newlyObservedTaxaCount": 1
  }
}

Limitations and assumptions

Observed loss does not by itself establish biological extinction.

Numbers and computed results must be finite; overflow produces an error. Numeric lists are limited to 100,000 entries; the rules above may require smaller limits. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.

Alternative or Complementary methods

Use Net Diversification Rate: Calculate signed event/exposure net diversification with independent origination/extinction counting error; unlike log endpoint richness growth, this requires explicit event and lineage-time inventories. For a complementary task, use Standing Diversity Through Time Binner: Bin range-through standing diversity using positive-duration half-open ranges on a supplied increasing forward-time axis, excluding endpoint-only touches; ranges do not prove continuous actual occupancy.

References

Extinction Magnitude Percent Taxa — tool.io

Similar or alternative tools

Net Diversification Rate
Calculate signed event/exposure net diversification with independent origination/extinction counting error; unlike log endpoint richness growth, this requires explicit event and lineage-time inventories.
Standing Diversity Through Time Binner
Bin range-through standing diversity using positive-duration half-open ranges on a supplied increasing forward-time axis, excluding endpoint-only touches; ranges do not prove continuous actual occupancy.