Species Divergence Time Calculator
Calculate species divergence time from genetic or morphological data. Combine molecular clock estimates with fossil calibration to date evolutionary split times.
🧬 Evolution📐 T_diverge = T_coal - T_within🧬 Biology
TMRCA between species (Ma)
Within-species coalescence (Ma)
Fossil minimum age calibration (Ma)
Please enter valid values.
Formula & Reference
| Variable | Symbol | Formula | Units |
|---|---|---|---|
| Species Divergence Time Calculator | — | T_diverge = T_coal - T_within | years or Ma |
Step-by-Step Examples
Example 1
Human-Chimp Split
Gene TMRCA=6.5 Ma, within-human diversity=1.0 Ma.
- Split = 6.5 - 1.0 = 5.5 Ma
- Consistent with fossil record 5-7 Ma
- Great apes diverged 8-12 Ma
✓ Species split ~5.5 Ma
Example 2
Mouse-Rat Divergence
Gene TMRCA=15 Ma, within-mouse=1 Ma. Fossil minimum: 12 Ma.
- Split estimate = 15-1 = 14 Ma
- Fossil calibration confirms >12 Ma
- Consistent with ~14 Ma paleontological estimates
✓ Split ~14 Ma (consistent with fossils)
Example 3
Recent Speciation
TMRCA=0.5 Ma between incipient species.
- Very recent split
- Incomplete lineage sorting expected
- Many ancestral polymorphisms shared across species
✓ Split ~0.5 Ma — very recent
Real-World Applications
Systematics
Date divergence times for phylogenetic tree construction.
Biogeography
Correlate splits with vicariance or dispersal events.
Comparative Biology
Relate trait evolution to speciation history.
Conservation
Identify evolutionarily distinct lineages deserving protection.
Common Mistakes to Avoid
⚠️
Confusing gene tree with species tree
Gene TMRCA always predates species split due to ancestral polymorphism. Correct by subtracting within-species coalescence time.
⚠️
Ignoring incomplete lineage sorting
At recent splits, gene trees may not match species tree. Use multiple genes for reliable species tree estimation.
⚠️
Over-relying on single gene
Different genes give different divergence estimates. Use Bayesian species tree methods with many loci.
Frequently Asked Questions
Why does gene divergence predate species split? ▾
Ancestral population has pre-existing diversity. Gene copies that diverge during speciation carry ancestral variation, making gene TMRCA older than species split.
What is incomplete lineage sorting? ▾
When ancestral polymorphisms are maintained through speciation events, genes may show conflicting topologies with the species tree.
What is the multispecies coalescent? ▾
Statistical model relating gene trees to species trees, accounting for incomplete lineage sorting. Used in BEAST2, SVDquartets.
How are fossil dates used? ▾
As minimum age constraints or calibration points for molecular clock. Bayesian methods assign probability distributions to fossil ages.
What is a speciation event? ▾
When two populations become reproductively isolated and begin diverging independently. Detected by FST, Fst outlier tests, or ecological differentiation.