# Neanderthal mtDNA rates under specified sampling times

Recomputed 2026-09-12. These scenarios supersede the earlier 30-versus-170 allocation and its 5.7–11.4-fold claims.

The 1,890 overlapping human–Neanderthal comparisons average 93.635 assigned changes on the Neanderthal branch and 102.884 on the human branch. They are descriptive counts, not independent observations. The separate consensus comparison has 89 and 88 changes.

For ancestor age T and specimen age d (years before present), rN/rH = (bN/bH) × T/(T−d). A species extinction date is not a specimen date. Generation length is assumed to be 25 years on both branches.

## Required branch rates

| Ancestor age | Specimen age | Neanderthal duration | Human changes/gen | Neanderthal changes/gen | Annual N/H ratio, mean branches |
|---|---|---|---|---|---|
| 6000 | 0 | 6000 | 0.429 | 0.390 | 0.910 |
| 6000 | 2000 | 4000 | 0.429 | 0.585 | 1.365 |
| 6000 | 3000 | 3000 | 0.429 | 0.780 | 1.820 |
| 4500 | 0 | 4500 | 0.572 | 0.520 | 0.910 |
| 4500 | 2000 | 2500 | 0.572 | 0.936 | 1.638 |
| 4500 | 3000 | 1500 | 0.572 | 1.561 | 2.730 |

## Conditional consensus test

| Ancestor age | Specimen age | Annual N/H ratio | Conditional 95% Wilson interval | Equal-annual-rate exact binomial p |
|---|---|---|---|---|
| 6000 | 0 | 1.011 | 0.754–1.356 | 1.00 |
| 6000 | 2000 | 1.517 | 1.131–2.035 | 0.00571 |
| 6000 | 3000 | 2.023 | 1.508–2.713 | 0.00000436 |
| 4500 | 0 | 1.011 | 0.754–1.356 | 1.00 |
| 4500 | 2000 | 1.820 | 1.357–2.442 | 0.0000793 |
| 4500 | 3000 | 3.034 | 2.262–4.069 | 7.23e-13 |

These intervals and tests condition on supplied dates, counts, topology, independent site events, and a constant rate on each branch. They omit uncertainty from alignment, recurrent mutation, selection, and shared genealogy. A consensus of differently aged specimens has no single actual sampling date. These scenarios demonstrate time dependence; they do not date Neanderthals or test POLG function.

## Specimen-level scenarios

neanderthal-time-scenarios.json also contains a test for each saved Neanderthal-versus-human-consensus comparison under each scenario. The same hypothetical age is applied to every specimen only to illustrate sensitivity. P-values are exploratory, correlated, and unadjusted for multiple testing; do not pool them as independent confirmations.