This is a technical discussion draft relating to the Population
Replacement Evidence post.
Revised 3 August 2026. This version replaces the draft posted on
2 August. The substantive change is in §9 and §10: the earlier version
described the four England_BB_highEEF outliers as surviving
independent testing, which read as a claim that they are demonstrable
British survivals. That does not follow from the argument of §7, and has
been corrected. A new §2 states the estimand explicitly, so everything
after it is renumbered by one. Full list of changes at the foot of the
post.
Summary
Two studies appear to disagree about whether ancestry from Neolithic
Britain persisted after the Bell Beaker migrations of the mid-third
millennium BC. Booth et al. (2021) reported a small but rising
Neolithic-related component through the Chalcolithic and Early Bronze
Age, and read it as evidence that the resident population left
descendants. Olalde et al. (2026), using a Lower Rhine–Meuse
source population unavailable in 2021, found the main English Beaker
group indistinguishable from that source and bounded any surviving
British Neolithic ancestry between zero and eight per cent.
Re-analysis of the supplementary data of both papers shows that they
do not disagree about how much ancestry survived. Placing Booth’s
individual-level estimates inside Olalde’s group definitions returns
2.52 per cent for the Beaker group and 8.55 per cent for the later
Chalcolithic–Early Bronze Age group, against Olalde’s zero and 7.3–7.9
per cent. The pattern of estimates censored at the zero boundary in
Booth’s own table independently distinguishes the two groups, recovering
the 2026 result from data available five years earlier. Both papers find
the same rise over time, and weighted regression on calibrated date
shows it to be a continuous gradient rather than a step between burial
categories: fitting date and a group indicator jointly, the date term
survives and the group term does not.
What the 2026 data cannot establish is where the surviving ancestry
came from. Seven candidate source populations — from Yorkshire to
Andalusia — return estimates spanning only 7.3 to 9.0 per cent and fit
the data comparably well, with the English Neolithic source ranking
third of seven. The reason is substantive rather than technical: English
Neolithic and continental Middle/Late Neolithic populations are
genuinely alike in hunter-gatherer content, the only axis on which this
design separates them. The published bound of nought to eight per cent
is therefore a statement of non-identifiability, not a confidence
interval, and no amount of additional sampling in the candidate source
regions will narrow it.
The quantity is well measured; the address is unknown. One extension
of an analysis already performed in the 2026 paper — identity-by-descent
between the English Chalcolithic–Early Bronze Age individuals and the
English Neolithic ones, a comparison absent from the published table by
construction — could settle it. A power calculation from that table’s
own detection rates indicates the test would be underpowered at the
coverage used and decisive at full group coverage.
1. Why this matters, and
why it is hard
The genetic transformation of Britain between roughly 2450 and 2000
BC is one of the most dramatic events in European prehistory. People
associated with the Bell Beaker complex arrived from the continent, and
within a few centuries the ancestry of the population buried in Britain
had changed by something like ninety per cent. What is disputed is not
that this happened but what it means: whether a resident population was
displaced, absorbed, or had already dwindled to the point where
"replacement" is the wrong word.
The residual matters more than its size suggests. If a few per cent
of Neolithic British ancestry survived into the Bronze Age, some
Neolithic families had descendants and the transition involved
intermarriage rather than pure displacement. If that residual rose over
time, as Booth and colleagues argued, then descendants of the Neolithic
population were not merely surviving but were increasingly represented —
which is very hard to reconcile with rapid violent replacement. And if
the residual is actually zero, the record is silent on all of this,
because you cannot infer anything from a signal you cannot see.
Two obstacles make the question hard, and both are statistical rather
than archaeological.
The first is that these ancestry proportions are estimated by a
method — qpAdm — that answers a narrow question. It asks whether a
proposed mixture of source populations is rejected by the data,
given a set of reference populations held out for comparison. A model
that is not rejected is not thereby confirmed. A proportion estimated at
zero may mean the ancestry is absent or may mean the method cannot see
it. Distinguishing these requires knowing how small a contribution the
design could have detected, which nobody has calculated for this
case.
The second obstacle is that ancestry proportions are estimated for a
named source. When you ask how much English Neolithic ancestry a
population carries, you get an answer conditioned on English Neolithic
being the right source. If a different but genetically similar
population were the true contributor, the estimate would come back much
the same. Booth and colleagues flagged exactly this, writing that it was
difficult to distinguish ancestry from Neolithic Britain from ancestry
from more western parts of continental Europe — northern France in
particular — where archaeogenetic data were then almost absent. They
judged that this was unlikely to account for much.
That judgement was the weakest joint in their argument. The 2026
paper supplies part of the missing data. What follows tests both.
2. The estimand, stated
precisely
Most of the confusion in this area comes from treating two different
quantities as one. It is worth separating them before any numbers are
quoted.
Olalde et al. (2026) model England_CA_EBA (n = 39,
median 1865 cal BC) as requiring a second Middle/Late Neolithic source
at 7.3–7.9 per cent alongside RhineMeuse_LNB_BB; the one-source model
fails at P = 2.8 × 10⁻¹⁰. The paper states the interpretive
range explicitly: nought per cent British if the component is wholly
continental, eight per cent if wholly British. That range is not
uncertainty about the size of the component. It is uncertainty about its
provenance.
The quantity at issue is therefore not the magnitude of the residue —
which is well measured, to within about two percentage points — but a
mixing parameter:
β = the proportion of the 7.3–7.9 per cent
second-source component that derives from populations resident in
Britain before c. 2450 BC, as against populations resident in
north-west continental Europe.
β = 1 means the entire component is indigenous survival: Neolithic
Britons contributed to the later gene pool at group level. β = 0 means
the incomers arrived carrying farmer ancestry already, and no Neolithic
Briton did. Everything published to date is consistent with any value in
[0, 1], and the substantive disagreement between the two papers — to the
extent there is one — is entirely a disagreement about β.
Three distinct processes can produce a 7–8 per cent second source
with β = 0, and they are worth naming because they have different
implications and different remedies:
- Founder sampling. The emigrant subset of the
Rhine–Meuse population was not a random draw from its source, and
carried more farmer ancestry than the thirteen sequenced
RhineMeuse_LNB_BB individuals.
- Continental top-up. Additional migration into
Britain after the initial Beaker horizon, from a north-west continental
population — northern France being the named candidate — with more
farmer ancestry.
- Proxy error. RhineMeuse_LNB_BB is simply the wrong
source, and the residue is an artefact of a mis-specified single
source.
Sections 3 to 6 establish that the residue is real and that its
magnitude is agreed. Sections 7 and 8 establish that β is not identified
by the published design. Section 10 returns to the three mechanisms
above; §11 sets out the one test that would separate them.
3. Data and method
Three published supplementary datasets are used. All figures below
can be regenerated from them by the accompanying script.
Booth et al. 2021, Supplementary Table 1
gives, for each of 98 individuals from Chalcolithic to Late Bronze Age
Britain, a point estimate of ancestry related to the Neolithic
populations of Britain, a standard error, and a calibrated radiocarbon
median. These estimates originate in the qpAdm models of Olalde et
al. 2018.
Olalde et al. 2026, Supplementary Tables 1, 3, 7, 9,
10, 12 and 14 give group assignments by genetic identifier,
qpAdm models for the English groups with the Lower Rhine–Meuse source in
place, distal three-way models decomposing ancestry into Balkan
Neolithic, western hunter-gatherer and Corded Ware components, and
identity-by-descent connections.
Olalde et al. 2018, Supplementary Table 1
gives autosomal SNP counts.
Merging on individual identifiers places Booth’s per-individual
estimates inside Olalde’s 2026 group boundaries. Coverage is 26 of the
28 individuals in England_BB, 28 of the 39 in England_CA_EBA, and 3 of
the 4 in England_BB_highEEF — I14200 is not in Booth’s table. The
remaining 44 Booth individuals are Scottish, Welsh, northern English or
Middle-to-Late Bronze Age and fall outside the English groups; they are
used only where the temporal analysis is stated as covering all dated
individuals.
Group summaries are inverse-variance weighted means. Heterogeneity is
assessed by Cochran’s Q, I², and the random-effects
between-individual standard deviation τ. Temporal models are weighted
least squares of ancestry proportion on calibrated median date, with the
residual scale factor φ = χ²/df used to correct slope standard errors
for over- or under-dispersion.
4. The two papers agree
about magnitude
| England_BB (26 of 28) |
2.52 % ± 0.84 |
0 % — cladal with RhineMeuse_LNB_BB,
P = 0.61 |
| England_CA_EBA (28 of 39) |
8.55 % ± 0.85 |
7.3–7.9 % (setup 1); 7.5–9.0 % (setups
2–3) |
| England_BB_highEEF (3 of 4) |
26.98 % ± 2.44 |
27–39 % in three-way models |
The estimates are not in conflict. They are the same numbers, reached
through different model structures — one without a Rhine–Meuse proxy and
one with it — and the concordance holds across an order-of-magnitude
range. Whatever else the 2026 paper achieved, it did not overturn
Booth’s measurements.
Two qualifications, both of which tighten the agreement rather than
loosening it. Booth’s per-individual standard errors derive from a
common set of f₄ statistics and are correlated; treating them
as independent makes the pooled standard errors above optimistic,
plausibly by a factor of order √2. And 19 of the 98 estimates sit
exactly on the zero boundary, which biases the pooled means upward.
5. The zero boundary is
diagnostic
qpAdm can return negative admixture proportions. Olalde 2018 reported
them censored at zero. This is normally a nuisance; here it carries
information.
If a group’s true British Neolithic ancestry were exactly zero, half
its individual estimates would fall below zero by chance and be reported
as zero. In England_BB, 13 of 26 estimates sit on the
boundary — a fraction of 0.500 against an expectation of 0.500
(binomial p = 1.00). In England_CA_EBA, 4 of
28; under a true value of zero the expectation is 14
(p = 1.8 × 10⁻⁴).
Simulating the censoring directly — drawing each individual from a
normal centred on an assumed common true value with that individual’s
own reported standard error, censoring at zero, re-pooling, 200,000
times:
| 0 % |
1.66 % (0.81–2.72) |
13.0 |
0.053 |
| 1 % |
2.21 % (1.21–3.39) |
10.6 |
0.294 |
| 2 % |
2.85 % (1.72–4.15) |
8.4 |
0.706 |
| 3 % |
3.58 % (2.33–4.98) |
6.4 |
0.949 |
Inverting the simulation gives a consistency interval of 0 to
3.25 per cent for England_BB’s true common value. Truncation
accounts for most but not all of the observed 2.52 per cent: under a
true value of exactly zero the expected pooled estimate is 1.66 per
cent, and the observation sits at the 95th percentile. Zero survives,
but only just.
For England_CA_EBA the same simulation excludes every true value
below about 7 per cent (P < 10⁻³ throughout); at 7.15 per
cent the observed pooled estimate sits at p = 0.058. The later
group’s residue is real and is not an artefact of censoring.
So Booth’s own data, read through nothing but their boundary counts,
say that the Beaker group’s Neolithic ancestry is indistinguishable from
zero and the Chalcolithic–Early Bronze Age group’s is not. That is the
2026 result, obtainable five years earlier from data already in
hand.
6. The rise is real, and
it is a gradient
England_BB has a median calibrated date of 2146 cal BC;
England_CA_EBA, 1865 cal BC (Mann–Whitney p = 1.8 × 10⁻⁵).
Olalde 2026 assigns the earlier group no additional Middle/Late
Neolithic ancestry and the later group 7.3–7.9 per cent. That is a rise,
in the same direction and of similar magnitude to Booth’s reported
increase from about 6 to about 12 per cent, obtained from independent
model specifications with the correct proxy in place.
Booth’s trend also survives being tested more stringently than they
tested it. A rank-sum comparison across a split chosen partly by
inspection is weak evidence; weighted regression on the continuous date
variable is not.
| All dated individuals |
87 |
+0.62 |
5.84 |
3.35 (p =
0.0008) |
3.03 |
| Excluding the highEEF outliers |
84 |
+0.82 |
7.52 |
5.20 (p <
10⁻⁶) |
2.09 |
| England_BB + England_CA_EBA only |
48 |
+1.83 |
5.69 |
4.15 (p = 3 ×
10⁻⁵) |
1.88 |
| …excluding I2462 as well |
47 |
+1.73 |
5.39 |
6.85 (p <
10⁻⁵) |
0.62 |
Spearman’s ρ is 0.509 (p = 4.9 × 10⁻⁷) across all dated
individuals and 0.592 (p = 9.5 × 10⁻⁶) on the restricted set.
Restricting to the 48 individuals inside the two English groups removes
any confounding from Scottish, Welsh or Middle Bronze Age individuals,
and strengthens the slope roughly threefold — the full-sample figure is
depressed by the later Bronze Age tail, where the trajectory
plateaus.
The rise is a gradient, not a step. Within
England_BB alone the slope is +1.26 pp/century (corrected Z =
1.77); within England_CA_EBA alone, +1.38 (corrected Z = 1.92).
Fitting date and a group indicator together, the date term survives
(Z = 5.02 excluding I2462) and the group step does not (+1.5
pp, Z = 1.24). Olalde’s two groups are not two states of the
population but two windows onto one continuous trajectory. This is the
strongest available vindication of Booth’s actual thesis, which was
gradualism: a group-level model with two categories cannot represent a
gradient, and the gradient is in the data.
7. What cannot be
identified is the address
Olalde 2026 tested nine candidate second sources for England_CA_EBA
across three SNP-filtering setups. The two Lower Rhine–Meuse sources
fail decisively. The remaining seven:
| TRB_N (Funnel Beaker) |
6 |
7.4 × 10⁻³ |
0.514 |
0.488 |
7.3–8.2 % |
| S_France_LN |
18 |
1.8 × 10⁻³ |
0.220 |
0.351 |
7.3–8.6 % |
| England_N |
27 |
2.2 × 10⁻³ |
0.205 |
0.334 |
7.6–8.8 % |
| Germany_Baalberge_MN |
3 |
1.4 × 10⁻³ |
0.115 |
0.244 |
7.8–8.9 % |
| NE_France_LN |
14 |
1.2 × 10⁻³ |
0.083 |
0.199 |
7.4–8.6 % |
| GlobularAmphora_LN |
10 |
6.3 × 10⁻⁴ |
0.051 |
0.099 |
7.9–9.0 % |
| N_Spain_LNCA |
45 |
3.1 × 10⁻⁴ |
0.037 |
0.100 |
7.6–8.7 % |
Across all 21 fits the point estimate ranges from 7.3 to 9.0 per cent
— a spread of 1.7 percentage points — while the candidate source ranges
geographically from Yorkshire to Andalusia. The quantity is estimated to
within about two points; the source is not estimated at all. England_N
ranks third of seven where models pass. There is no statistical basis
for preferring the British source and none for excluding it.
This is why Booth’s caveat matters more, not less, after 2026. They
worried that western continental Neolithic populations could not be told
apart from British ones. NE_France_LN returns 7.4–8.6 per cent with fits
comparable to England_N’s. Their caveat has been tested and
confirmed as unresolvable with this design, not refuted.
The 2026 bound of 0 to 8 per cent is a statement of that
non-identifiability. It is not a confidence interval and should not be
collapsed into one. Sampling uncertainty on the quantity is roughly ±2.4
points; the 0-to-8 range is source-attribution ambiguity, a different
kind of ignorance that does not shrink with more British
individuals.
8. What the
cladality result does and does not bound
England_BB’s cladality with RhineMeuse_LNB_BB at P = 0.61
licenses a bound, not an absence. The bound can be calculated (Appendix
A).
With six outgroups the one-way model carries 5 degrees of freedom,
and P = 0.61 corresponds to an observed χ² of 3.61. Inverting
the non-central χ² gives a one-sided 95 per cent upper bound on the
non-centrality of λ ≤ 6.88. The mapping λ ≈ κ(α/SE)² is calibrated
against the two groups that demonstrably require a second source, giving
κ = 0.96 across six checks. The standard error for a two-source
England_BB model, obtained by cross-target calibration against
Supplementary Table 10, is 0.0130–0.0140 — about 8 per cent
larger than England_CA_EBA’s, since England_BB’s higher
per-individual coverage does not compensate for eleven fewer
individuals. Hence:
England_BB can conceal up to 3.5 per cent local Neolithic
ancestry (95 per cent upper bound; 3.46–3.75 per cent across the three
SNP setups).
The power curve matters as much as the bound. The design reaches 50
per cent power only at 3.5 per cent, 80 per cent power at 4.7–5.1 per
cent, and 95 per cent power at 5.9–6.4 per cent. A genuine residue of
four per cent would have been missed more often than not.
Booth’s pooled England_BB estimate of 2.52 per cent, and the 0–3.25
per cent consistency interval from the censoring simulation, sit
entirely inside that window. Two independent routes converge on the same
ceiling. The two papers do not disagree here either; the 2026 design
simply cannot see a residue this small.
9. Structure inside the groups
Cochran’s Q on Booth’s estimates within each Olalde
group:
| England_BB |
20.9 |
25 |
0.70 |
0 % |
0.00 pp |
| England_CA_EBA |
81.0 |
27 |
2.6 × 10⁻⁷ |
66.7 % |
6.36 pp |
England_BB, once Olalde’s four outliers are removed, is statistically
homogeneous. Olalde’s decision to excise England_BB_highEEF is therefore
vindicated on Booth’s own numbers: those four individuals carried the
entirety of the Beaker-period signal, and the magnitude of their
Neolithic-related component — 27 to 39 per cent, against 27.0 % ± 2.4
pooled from Booth’s estimates — survives independent testing with a
proper Rhine–Meuse proxy in place.
It does not follow that these are demonstrable British survivals, and
the paper should not be read as claiming so. The non-identifiability of
§7 applies to the outliers with undiminished force: their component is
better measured than the group-level residue, being an order of
magnitude larger, but it is no better addressed. Nothing in the
design distinguishes a British Neolithic contribution from a continental
one at 27 per cent any more than at 8 per cent. Appendix D.2 makes the
point directly — England_BB_highEEF’s WHG/(WHG + Balkan_N) ratio is
0.239, inside the 0.217–0.246 continental Middle/Late Neolithic cluster
and 0.03 from England_N’s 0.207, a separation smaller than the
individual-level scatter in England_N itself (0.180–0.230). These four
individuals are people with substantially more farmer ancestry than
their contemporaries. Whether that ancestry was acquired in Britain or
carried across the Channel is exactly the question this paper argues
cannot presently be answered.
England_CA_EBA is not homogeneous, and its heterogeneity has a single
cause. Removing one individual — I2462, Sk 220053 from East Kent
Access Road, 35.3 ± 3.8 per cent, z = +7.04, dated 2131–1890
cal BC — leaves Q = 28.9 on 26 df (p = 0.32),
τ = 1.51 pp, and a group mean of 7.15 per cent in close agreement with
Olalde’s 7.3–7.9. Booth identified her as the latest individual carrying
substantial British Neolithic ancestry. Olalde 2026 separated four
outliers from the Beaker group and retained this statistically
comparable fifth inside a 39-individual pool where she contributes about
0.7 points to the group mean. That is not an error — a group-level
analysis is entitled to pool — but it means the count of individually
demonstrable Neolithic-descended people in the record is five, not
four.
The rise, however, is not carried by the outliers.
Decomposing the 4.72-point gap between the two groups’ unweighted
means:
| none |
7.40 % |
4.72 pp (100 %) |
| I2462 |
6.36 % |
3.68 pp (78 %) |
| top 2 |
6.06 % |
3.38 pp (72 %) |
| top 3 |
5.76 % |
3.08 pp (65 %) |
| top 5 |
5.13 % |
2.45 pp (52 %) |
The Hodges–Lehmann shift between the groups is 3.90 points, and a
quarter of England_CA_EBA individuals exceed England_BB’s 95th
percentile. This is a broad distributional shift, not a handful of
surviving families visible against an unchanged background — a
distinction that matters, because a broad shift is hard to explain by
lineage survival and easy to explain by continuing gene flow from
wherever the source turns out to be.
Two further features of England_CA_EBA, both invisible at group
level. The within-group residual correlates with date even after I2462
is removed (r = +0.50, p = 0.009), so the gradient of
§6 runs inside the group as well as between the groups. And there is a
hint of regional structure: Amesbury Down (n = 5) averages 2.10
per cent against East Kent Access (n = 3) at 10.43 per cent. At
these sample sizes that is a hypothesis rather than a finding, but it is
precisely the kind of pattern a pooled model is guaranteed to erase.
10. The reconciliation
Both papers are correct. They are describing different phases of one
sequence, and the appearance of conflict comes from a difference in what
each was able to name.
The Beaker phase (England_BB, median 2146 cal BC).
Local Neolithic ancestry is indistinguishable from zero, at a detection
ceiling of about 3.5 per cent. Booth’s boundary structure and Olalde’s
cladality test say the same thing. Four individuals carry a large and
robustly measured Neolithic-related component, and a fifth (I2462) sits
inside the later group; whether any of the five descends from Neolithic
Britain is subject to the same non-identifiability as the group-level
residue.
The Chalcolithic–Early Bronze Age phase (England_CA_EBA,
median 1865 cal BC). A second Middle/Late Neolithic component
of 7 to 9 per cent is required, robustly, in both analyses. The increase
from the earlier phase is real, is reproduced by Olalde’s own models, is
a continuous gradient rather than a step, and is a broad shift rather
than an outlier effect.
The source of that component is unidentified and, with this
design, unidentifiable. It lies somewhere between 0 and 8 per
cent British. Booth’s inference that it represents a resurgence of
specifically British Neolithic ancestry is unsupported; so is
the inference that it represents continental ancestry arriving
pre-mixed. The honest statement is that the ancestry rose and we do not
know whose it was.
The consequence for the wider argument is uncomfortable for both
sides. A rising Neolithic-related component after about 2100 BC no
longer functions as evidence against rapid displacement, because a
continental origin for that component is fully consistent with the data
and would say nothing about British survival. It also does not function
as evidence for displacement. The quantity is well measured and
interpretively inert until the source is pinned down.
In the terms of §2, both papers measure the same residue and neither
identifies β. Booth’s reading assumes β close to 1; the natural reading
of Olalde’s cladality result assumes β close to 0. Neither assumption is
licensed. Of the three mechanisms that would produce the observed
component with β = 0, none can currently be excluded: founder sampling
is unconstrained because the thirteen sequenced RhineMeuse_LNB_BB
individuals are a thin sample of a large source region; continental
top-up is positively suggested by the broad distributional shift of §9,
which is easier to explain by continuing gene flow than by the survival
of a few families; and proxy error, while made less likely by the
cladality of England_BB with the same source, is not eliminated by it.
It is worth noting that the second of these — continental top-up — is
the mechanism that the temporal gradient of §6 most naturally suggests,
and it is the one under which the entire interpretive weight placed on
the rising residue collapses.
11. What would resolve it
Four interventions suggest themselves. Three can be tested against
the supplementary data, and the results (Appendix D) reorder them
substantially.
1. Identity-by-descent between England_CA_EBA and England_N.
The only proposal that can work, it is a one-line extension of an
analysis already performed, and it would be decisive.
Supplementary Table 14 reports 5,846 IBD pairs. Checked against the
table’s own population labels, England-by-England pairs number
zero — not because none exist, but because the table’s scope is
pairs featuring a Lower Rhine–Meuse individual, so the comparison was
never attempted. Shared segments carry information about specific recent
common ancestors that no f₄ ratio supplies, and this is the one
axis on which a British source and a continental one must differ.
Appendix E works out what the test would yield. In outline: the
method has ample resolution at the required time depth (nineteen
detected pairs in the table span date gaps above 1,600 years), the
near-contemporary full-ancestry detection rate is 17.0 per cent of
possible pairs, and the expected yield for a 7.6 per cent ancestry
component runs from 3.4 to 13.6 detections at full group coverage
depending on how severely one assumes segment detection decays across
1,600 years. Against a continental-source null that predicts no
England_N-specific excess, that is a decisive test. At the coverage
actually used in Supplementary Table 14 — 19 English Neolithic and 11
English Chalcolithic–EBA individuals — the expected yield is 0.7 to 2.7
and the test is underpowered.
Three design points. Relatedness among the English Neolithic
individuals is substantial: at least eight of the nineteen belong to one
annotated pedigree, so the effective number of independent pairs is well
below the nominal count and the sample should be pruned. The coverage
threshold admitting only 12 of 39 England_CA_EBA individuals will need
relaxing. And the arm against England_N should be run simultaneously
against date-matched continental candidates so that time decay, the
largest nuisance parameter, cancels in the ratio — Ireland_MN
(n = 8, median 5410 BP) and MN_Wartberg (n = 26,
median 5140 BP) are the best-matched to England_N’s median of about 5500
BP and are already in the table.
2. Individual-level re-analysis of England_CA_EBA with the
Rhine–Meuse proxy. The group-level result conceals one
demonstrable survival, a within-group temporal gradient, and possible
regional structure. Section 8 does what can be done from Booth’s
estimates; doing it properly requires running the 2026 models per
individual.
3. A rotating qpAdm competition with a right set chosen to
separate the candidate sources. Less promising than it looks, and
Appendix D explains why. The 2026 paper contains an orthogonal
discriminator it does not apply here: the ratio WHG/(WHG + Balkan_N)
from the distal three-way models. That statistic separates the
Rhine–Meuse sources (0.397–0.492) from everything else very cleanly, and
the paper uses it to good effect. But England_N’s own value, computed
from the 14 England_N individuals in Supplementary Table 7, is
0.207 with an individual range of 0.180 to 0.230 —
sitting inside the continental Middle/Late Neolithic cluster at
0.217 to 0.246. English Neolithic and continental Middle/Late Neolithic
populations are genuinely alike in hunter-gatherer content, to within
about the individual scatter. The seven candidates behave alike in the
qpAdm models because they are alike on the axis this design
resolves. A better right set helps only if it resolves something other
than hunter-gatherer level, and it is not obvious what that would be.
The non-identifiability is substantive, not a defect of outgroup
choice.
It is worth noting separately that England_CA_EBA does not appear in
Supplementary Table 9 at all. The one orthogonal statistic in the paper
was never computed for the group that carries the residue.
4. More northern French Middle/Late Neolithic genomes. This
will not help. Across the seven candidate sources, group size
ranges from 3 to 45 — a fifteen-fold span — and the standard error on
the second-source proportion is 0.011 to 0.013 throughout. There is no
relationship between how many individuals a source group contains and
how well it fits: N_Spain_LNCA at n = 45 ranks sixth or
seventh, Germany_Baalberge_MN at n = 3 ranks fourth, TRB_N at
n = 6 ranks first (Spearman ρ between source n and log
P = −0.32, p = 0.48 in setup 2; −0.18, p =
0.70 in setup 3). Sampling density in the source is not the binding
constraint. More French genomes are worth having for other reasons — a
northern French population genuinely distinct from those sampled would
change the picture — but they will not tighten this estimate.
12. Conclusion
The disagreement between these two papers was never about arithmetic.
Placed side by side under a common set of group definitions, they return
the same numbers to within their standard errors: near-zero surviving
Neolithic ancestry among the Beaker-associated dead, seven to nine per
cent among their Chalcolithic and Early Bronze Age successors, and a
continuous rise between the two that neither paper’s model structure was
designed to represent but which both papers’ data contain.
What separates them is a question about naming rather than counting.
Booth and colleagues measured a quantity and called it British; Olalde
and colleagues measured the same quantity and declined to call it
anything, because with a proper Rhine–Meuse proxy in the model, seven
Neolithic populations spread across western Europe fit it equally well.
The 2026 bound of nought to eight per cent is not a measurement with
wide error bars. It is a statement that the question has two answers and
the data cannot choose.
That is a genuinely awkward place for the field to be, and it is
worth being clear about how awkward. The rising Neolithic-related
component after about 2100 BC has done a lot of interpretive work in
recent discussion of the Beaker transition — as evidence that
displacement was incomplete, that intermarriage was common, that the
population of Neolithic Britain left descendants. None of that is
refuted here. But none of it is supported either, because a component
whose source is unknown cannot tell us whether anyone survived. The
number is solid and the inference is suspended.
The most useful thing to take from the exercise is that the
non-identifiability turns out to be real rather than fixable by more of
the same. Neolithic Britain and Neolithic northern France, Germany and
Iberia are alike in the one respect that this method resolves.
Sequencing more of them will not separate them.
What might is a technique that looks at shared segments of chromosome
rather than aggregate ancestry proportions — and here the news is better
than the rest of this paper. The relevant data already exist, in a table
in the 2026 paper’s own supplement. The comparison it needs has never
been run, because that table was built to answer a different question
and by construction contains no English-by-English pairs at all. But the
same table contains everything required to work out what the comparison
would yield: how well identity-by-descent survives the sixteen centuries
between Neolithic and Early Bronze Age Britain, and how often a
seven-per-cent ancestry component leaves a detectable segment. The
answer is that at the coverage used in the published table the test
would be underpowered, and at full group coverage it would be decisive —
somewhere between three and fourteen detections where a continental
source predicts essentially none.
That is an unusually cheap way to settle a question this old. No new
excavation, no new sequencing, no new samples: one comparison, on data
already published, between two sets of people who lived in the same
country sixteen hundred years apart.
Limitations
Booth’s per-individual standard errors derive from a common set
of f₄ statistics and are correlated. Inverse-variance pooling
assumes independence and therefore understates the pooled standard
errors, plausibly by around √2. All pooled intervals should be read as
wider than quoted.
Booth’s estimates come from Olalde 2018’s models, which lacked a
Rhine–Meuse source. They are not independent measurements of the same
parameter as Olalde 2026’s; the agreement in §4 is consistency under a
change of specification, not replication.
Cochran’s Q has low power at these sample sizes.
I² = 0 for England_BB is a failure to detect heterogeneity, not
a demonstration of its absence.
Residual z-scores fail normality tests in both groups
(Shapiro–Wilk W = 0.70 and 0.76), driven by the zero floor in
England_BB and by I2462 in England_CA_EBA. Normal-theory intervals
throughout are indicative; the permutation and simulation results are
more reliable.
11 of the 39 England_CA_EBA individuals and 2 of the 28
England_BB individuals are newly reported in 2026 and absent from
Booth’s table.
The detection floor in §8 rests on the empirically calibrated
mapping λ ≈ κ(α/SE)². The six calibration checks scatter between κ =
0.83 and 1.21. A direct recomputation would require the 1240k genotype
data.
The censoring simulation in §5 assumes a single common true value
per group and independent errors. The first assumption is falsified for
England_CA_EBA (§9), so that interval applies to the group’s central
tendency rather than to individuals.
qpAdm P-values across Supplementary Tables 9–12 come
from a large number of tested models. None quoted here has been
corrected for multiple testing, and none should be read as a probability
that a model is true.
The regional contrast in §9 rests on 5 and 3 individuals
respectively and should not be relied on.
Reproducibility
No new data are generated here. All results derive from three
published supplementary datasets:
- Booth et al. 2021, Supplementary Table 1 (Cambridge Core,
supplementary material to doi:10.1017/S0959774321000019)
- Olalde et al. 2018, Supplementary Tables (Nature
555, doi:10.1038/nature25738)
- Olalde et al. 2026, Supplementary Tables 1, 3, 7, 9, 10, 12
and 14 (Nature, doi:10.1038/s41586-026-10111-8)
The script reproduce.py takes these three workbooks as
input and prints every number reported here, in the order it appears,
including the appendix tables. Dependencies: Python 3,
numpy, pandas, scipy,
openpyxl. The random seed for the censoring simulation is
fixed at 20260802; simulation figures are stable to the second decimal
place across seeds.
Script: https://claude.ai/public/artifacts/97845468-1666-45b9-877c-c9ac70cf7fc0
GitHub Repo: https://github.com/TimDaw37/beaker-neolithic-residue
Appendix A —
Detection floor for England_BB
Degrees of freedom. With n_right outgroups and
n_left populations on the left, qpAdm’s rank test has df = 1 × (n_right
− n_left + 1). Supplementary Tables 9–12 use six outgroups (OldAfrica,
IronGates_HG, Turkey_Neo, WSHG, CHG_Iran_N, Russia_Afanasievo), so the
one-way model has 5 df and the two-way model 4 df.
Table A1 — cross-target standard-error calibration.
Supplementary Table 10 runs one model family against several targets,
allowing standard errors to be compared with model structure held fixed.
Values are medians across the ten source pairings.
| England_BB |
28 |
0.0150 |
0.0160 |
0.0160 |
| England_CA_EBA |
39 |
0.0140 |
0.0145 |
0.0150 |
| England_BB_highEEF |
4 |
0.0220 |
0.0230 |
0.0230 |
| RhineMeuse_LNB_BB |
13 |
0.0155 |
0.0160 |
0.0170 |
Ratio SE(England_BB)/SE(England_CA_EBA) = 1.071, 1.103, 1.067; mean
1.081. Applied to the Supplementary Table 12 standard errors for
England_CA_EBA (0.012, 0.012, 0.013), this gives 0.0130–0.0140 for a
two-source England_BB model.
Table A2 — calibrating λ ≈ κ(α/SE)². For the two
groups that demonstrably require a second source, the one-way model’s
failure should have non-centrality proportional to the squared Wald
statistic of the omitted component.
| England_CA_EBA (s1) |
2.79 × 10⁻¹⁰ |
53.4 |
0.076 |
0.012 |
45.1 |
1.21 |
| England_CA_EBA (s2) |
1.49 × 10⁻⁹ |
49.8 |
0.088 |
0.012 |
58.8 |
0.83 |
| England_CA_EBA (s3) |
3.82 × 10⁻⁷ |
38.0 |
0.079 |
0.013 |
41.9 |
0.89 |
| England_BB_highEEF (s1) |
1.64 × 10⁻²¹ |
107.1 |
0.243 |
0.024 |
107.5 |
1.00 |
| England_BB_highEEF (s2) |
1.01 × 10⁻²² |
112.9 |
0.260 |
0.025 |
113.2 |
1.00 |
| England_BB_highEEF (s3) |
8.23 × 10⁻²⁰ |
99.1 |
0.241 |
0.024 |
105.8 |
0.93 |
Median κ = 0.96. The fit is near-exact for the high-signal outlier
group and scatters by roughly ±20 per cent for England_CA_EBA.
Table A3 — the bound and the power curve.
England_BB’s observed one-way statistic is χ² = 3.61 on 5 df (P
= 0.607); the critical value at α = 0.05 is 11.07.
| One-sided 95 % upper bound on λ given χ² =
3.61 |
≤ 6.88 |
≤ 3.46–3.75 % |
| λ giving 50 % power |
6.99 |
3.49–3.78 % |
| λ giving 80 % power |
12.83 |
4.73–5.12 % |
| λ giving 95 % power |
19.78 |
5.87–6.36 % |
Autosomal SNP coverage (Olalde 2018 Supplementary
Table 1): England_BB, 26 of 28 individuals with counts, median 663,686,
range 14,794–913,255. England_CA_EBA, 28 of 39, median 491,782, range
17,178–891,333. England_BB_highEEF, 3 of 4, median 700,532, range
136,956–729,987.
Appendix B — Censoring
simulation
200,000 draws per row. Each individual is drawn from N(true, SE_i²)
using its own reported standard error, censored at zero, and re-pooled
by inverse variance.
| 0 % |
1.66 (0.81–2.72) |
13.0 |
0.053 |
1.71 |
14.0 |
< 0.001 |
| 1 % |
2.21 (1.21–3.39) |
10.6 |
0.294 |
2.26 |
11.6 |
< 0.001 |
| 2 % |
2.85 (1.72–4.15) |
8.4 |
0.706 |
2.90 |
9.3 |
< 0.001 |
| 3 % |
3.58 (2.33–4.98) |
6.4 |
0.949 |
3.62 |
7.3 |
< 0.001 |
| 5 % |
5.25 (3.80–6.77) |
3.4 |
≈ 1 |
5.29 |
4.2 |
< 0.001 |
| 7.15 % |
7.24 (5.67–8.84) |
1.5 |
≈ 1 |
7.27 |
2.1 |
0.058 |
Observed: England_BB, 13 zeros of 26, pooled 2.52 %. England_CA_EBA,
4 zeros of 28, pooled 8.55 %.
Inverted consistency interval for England_BB’s true common value:
0.00 % to 3.25 %.
Appendix C — Temporal
analysis
Group chronology (Booth calibrated medians, cal
BC):
| England_BB_highEEF |
3 |
2289 |
2340–2190 |
| England_BB |
21 |
2146 |
2261–2091 |
| England_CA_EBA |
27 |
1865 |
2064–1814 |
England_BB earlier than England_CA_EBA: Mann–Whitney p = 1.8
× 10⁻⁵.
Weighted regression on date. Slope in percentage
points per century; corrected Z uses the residual scale factor
φ.
| All dated |
87 |
+0.62 |
5.84 |
3.35 |
8 × 10⁻⁴ |
3.03 |
| Excluding highEEF |
84 |
+0.82 |
7.52 |
5.20 |
< 10⁻⁶ |
2.09 |
| England_BB + CA_EBA |
48 |
+1.83 |
5.69 |
4.15 |
3 × 10⁻⁵ |
1.88 |
| …excluding I2462 |
47 |
+1.73 |
5.39 |
6.85 |
< 10⁻⁵ |
0.62 |
| England_BB alone |
21 |
+1.26 |
1.44 |
1.77 |
0.077 |
0.66 |
| England_CA_EBA alone |
27 |
+1.38 |
3.19 |
1.92 |
0.055 |
2.75 |
Note that φ < 1 in two rows: the reported standard errors there
slightly overstate the scatter, so the corrected Z is
conservative.
Gradient versus step (date and a group indicator
fitted jointly):
| With I2462 |
+1.35 pp/century (Z = 2.60) |
+3.40 pp (Z = 1.63) |
1.81 |
| Without I2462 |
+1.52 pp/century (Z = 5.02) |
+1.52 pp (Z = 1.24) |
0.61 |
Distribution-free checks. Spearman ρ = 0.509
(p = 4.9 × 10⁻⁷) on all dated individuals; 0.592 (p =
9.5 × 10⁻⁶) on the restricted set. Split at 2000 cal BC: earlier
n = 39, mean 5.9 %; later n = 48, mean 11.5 %;
Mann–Whitney one-tailed p = 3.9 × 10⁻⁶. Restricted
Mann–Whitney, England_CA_EBA > England_BB: p = 0.0011.
Permutation test on the restricted slope excluding I2462, 20,000 draws:
p < 5 × 10⁻⁵.
Appendix D — Testing the
four proposals
D.1 Source sample
size does not predict fit
England_CA_EBA, two-way models with RhineMeuse_LNB_BB (Supplementary
Table 12), against source group sizes from Supplementary Tables 1 and
3:
| MLN_Belgium |
18 |
1.3 × 10⁻⁹ |
1.4 × 10⁻⁸ |
2.2 × 10⁻⁶ |
3.2 % |
3.6 % |
3.7 % |
0.013 |
| MN_Wartberg |
40 |
6.5 × 10⁻⁷ |
1.7 × 10⁻⁵ |
5.7 × 10⁻⁴ |
5.9 % |
6.8 % |
6.4 % |
0.013 |
| Germany_Baalberge_MN |
3 |
1.4 × 10⁻³ |
0.115 |
0.244 |
7.8 % |
8.9 % |
7.9 % |
0.012 |
| TRB_N |
6 |
7.4 × 10⁻³ |
0.514 |
0.488 |
7.3 % |
8.2 % |
7.5 % |
0.011 |
| GlobularAmphora_LN |
10 |
6.3 × 10⁻⁴ |
0.051 |
0.099 |
7.9 % |
9.0 % |
8.3 % |
0.013 |
| England_N |
27 |
2.2 × 10⁻³ |
0.205 |
0.334 |
7.6 % |
8.8 % |
7.9 % |
0.012 |
| S_France_LN |
18 |
1.8 × 10⁻³ |
0.220 |
0.351 |
7.3 % |
8.6 % |
7.7 % |
0.012 |
| NE_France_LN |
14 |
1.2 × 10⁻³ |
0.083 |
0.199 |
7.4 % |
8.6 % |
7.7 % |
0.012 |
| N_Spain_LNCA |
45 |
3.1 × 10⁻⁴ |
0.037 |
0.100 |
7.6 % |
8.7 % |
7.9 % |
0.012 |
One-way model with RhineMeuse_LNB_BB alone: England_CA_EBA P
= 2.79 × 10⁻¹⁰, 1.49 × 10⁻⁹, 3.82 × 10⁻⁷. England_BB P = 0.607,
0.838, 0.881, 0.188 (setup 4).
Correlations between log₁₀ source n and log₁₀ P
across the seven non-Rhine-Meuse sources: Pearson r = −0.348
(p = 0.445) setup 2, −0.321 (p = 0.482) setup 3;
Spearman ρ = −0.321 (p = 0.482) and −0.179 (p =
0.702).
D.2 The hunter-gatherer
discriminator
Group-level distal models (Balkan_N + WHG + Germany_CordedWare),
Supplementary Table 9, setup 1:
| RhineMeuse_LNA_Vlaardingen/CW |
0.424 |
0.410 |
0.165 |
0.492 |
| RhineMeuse_LNB_BB |
0.105 |
0.069 |
0.826 |
0.397 |
| England_BB |
0.116 |
0.068 |
0.816 |
0.370 |
| RhineMeuse_EBA |
0.146 |
0.066 |
0.788 |
0.311 |
| France_BB_Steppe |
0.288 |
0.094 |
0.618 |
0.246 |
| England_BB_highEEF |
0.267 |
0.084 |
0.649 |
0.239 |
| Czechia_BB |
0.237 |
0.072 |
0.691 |
0.233 |
| France_BB_NoSteppe |
0.755 |
0.220 |
0.026 |
0.226 |
| SEGermany_BB |
0.252 |
0.070 |
0.677 |
0.217 |
England_CA_EBA does not appear in this table.
England_N’s own composition, from the 14 England_N individuals
present in Supplementary Table 7: mean Balkan_N 0.785, mean WHG 0.204,
ratio 0.207, individual median 0.207, range
0.180–0.230. That places English Neolithic inside the 0.217–0.246
continental cluster and about 0.19 away from the Rhine–Meuse
sources.
Limitation. Differencing England_BB against
England_BB_highEEF by mass balance gives the added component a ratio of
0.089–0.101 across setups, below England_N’s 0.207 and below every
candidate. The three-way distal model is evidently not cleanly additive
across groups with different Corded Ware fractions (0.816 versus 0.649),
so that figure should not be treated as an estimate of the added
component’s true hunter-gatherer content. The comparison that stands is
the direct one between England_N and the continental groups.
D.3 IBD coverage of
the English individuals
Supplementary Table 14 contains 5,846 pairs with segments above 12
cM. Pairs involving an English individual, by group:
| England_BB × RhineMeuse_LNB_BB |
26 |
| England_CA_EBA × RhineMeuse_LNB_BB |
20 |
| England_BB × RhineMeuse_EBA |
7 |
| England_N × RhineMeuse_MN_Tiel |
7 |
| England_BB_highEEF ×
RhineMeuse_LNB_BB |
5 |
| England_CA_EBA × RhineMeuse_EBA |
4 |
| England_CA_EBA ×
RhineMeuse_MN_Wartberg |
2 |
| England_BB × RhineMeuse_MLN_Belgium |
2 |
| England_CA_EBA ×
RhineMeuse_LNA_Vlaardingen/CW |
1 |
| England_BB ×
RhineMeuse_LNA_Vlaardingen/CW |
1 |
| England_N × RhineMeuse_MN_Swifterbant |
1 |
| England_N × RhineMeuse_MN_Wartberg |
1 |
| England_BB × RhineMeuse_MN_Wartberg |
1 |
| England × England |
0 |
Individuals available, counted by mapping the table’s identifiers
onto Olalde’s Supplementary Table 3 group assignments: England_BB 16 of
28, England_CA_EBA 12 of 39, England_N 6 of 27, England_BB_highEEF 1 of
4. Counted instead by the table’s own population-label columns — which
are more inclusive, absorbing England_N_Megalithic and the
kinship-annotated variants — the England_N and England_CA_EBA figures
rise to 19 of 27 and 11 of 39. Both counts are reported throughout,
because the two mappings do not agree and the difference matters for the
power calculation in Appendix E; on either count, roughly two-thirds of
the relevant individuals are absent. The nine England_N × Rhine–Meuse
Neolithic pairs have longest segments of 12.7–20.0 cM.
D.4 Structure within
England_CA_EBA
Largest absolute residuals against the common-effect estimate of 8.55
per cent:
| I2462 |
East Kent Access |
35.3 ± 3.8 % |
+7.04 |
| I6777 |
Wilsford G.54 |
0.0 ± 4.0 % |
−2.14 |
| I2597 |
Amesbury Down |
0.9 ± 4.0 % |
−1.91 |
| I5373 |
Carsington Pasture Cave |
0.0 ± 4.5 % |
−1.90 |
| With I2462 |
8.55 % |
81.0 / 27 |
2.6 × 10⁻⁷ |
66.7 % |
6.36 pp |
| Without I2462 |
7.15 % |
28.9 / 26 |
0.32 |
10.0 % |
1.51 pp |
Residual against calibrated date, I2462 removed: r = +0.501,
p = 0.009. By genetic sex, I2462 removed: male n = 16,
mean 6.58 %; female n = 10, mean 6.35 % (Mann–Whitney
p = 0.83). Sites with more than one dated individual, I2462
removed: Amesbury Down n = 5, mean 2.10 %; Baston and Langtoft
n = 2, mean 7.60 %; East Kent Access n = 3, mean 10.43
%.
Appendix E —
Specification and power of the IBD test
E.1 The comparison
is absent by construction
Checked against Supplementary Table 14’s own population-label columns
rather than by external mapping: of 5,846 reported pairs, 1,157 carry
population labels for both members, and no pair has English
individuals on both sides. Every one of the 78 pairs involving
an English individual has a Lower Rhine–Meuse partner, which is the
table’s stated scope.
Individuals available under the table’s own labels: 19 England_N
(including England_N_Megalithic and kinship-annotated variants), 11
England_C_EBA. Full group sizes from Supplementary Table 3 are 27 and
39.
E.2 The
method has resolution at the required depth
Date gaps among the 1,157 pairs with dates for both members:
| 0–200 |
483 |
16.1 cM |
| 200–400 |
224 |
14.3 cM |
| 400–800 |
274 |
14.1 cM |
| 800–1200 |
124 |
13.8 cM |
| 1200–1600 |
33 |
13.6 cM |
| 1600–1961 |
19 |
13.1 cM |
Spearman ρ between gap and longest segment = −0.341 (p = 5.9
× 10⁻³³). The required comparison spans roughly 1,600 years — England_N
has a median date near 5500 BP, England_CA_EBA near 3800 BP. Detection
at that depth occurs in the existing data: nineteen pairs exceed a
1,600-year gap, and the longest recorded is 1,961 years. Segment lengths
compress toward the 12 cM reporting threshold but do not vanish. The
clearest single instance is KD070.SG (England_Northumberland_EBA, 4306
BP) sharing 16.0 cM with an MN_Wartberg individual at 5164 BP across 858
years.
E.3 Benchmark detection
rates
| England_BellBeaker × LNB_Bell_Beaker |
16 × 11 |
176 |
30 |
17.0 % |
15.6 cM |
| England_C_EBA × LNB_Bell_Beaker |
11 × 11 |
121 |
18 |
14.9 % |
14.2 cM |
| England_N × MN_Tiel |
19 × 2 |
38 |
17 |
44.7 % |
14.5 cM |
The first row is the appropriate benchmark: near-contemporary
individuals with essentially all ancestry from the partner population.
The third row’s high rate reflects only two MN_Tiel individuals, at
least one of whom shares with many England_N individuals, and should not
be used for scaling.
E.4 Expected yield
Modelling detections as Poisson with rate proportional to the
ancestry fraction f = 0.076 times the benchmark rate of 0.170
(30 detections in 176 possible pairs), times a decay factor for the
1,600-year separation:
| None |
current (19 × 11) |
209 |
2.7 |
0.93 |
0.51 |
| None |
full groups (27 × 39) |
1,053 |
13.6 |
1.00 |
1.00 |
| 50 % |
current |
209 |
1.4 |
0.74 |
0.16 |
| 50 % |
full groups |
1,053 |
6.8 |
1.00 |
0.97 |
| 75 % |
current |
209 |
0.7 |
0.49 |
0.03 |
| 75 % |
full groups |
1,053 |
3.4 |
0.97 |
0.66 |
Under the continental-source null the England_N-specific excess is
zero, so any detection above the shared-deep-ancestry background is
evidence for a British source. At full group coverage the test
discriminates decisively across the whole range of decay assumptions; at
the coverage used in the published table it does not.
E.5 Design requirements
Prune for relatedness. At least three of the 19
England_N individuals carry explicit kinship annotations, and those
annotations reference a further five identifiers that also appear in the
table — I21393, I21389, I30334, I30304, I21395, I30332, I30302. A
pedigree therefore spans something like eight of the nineteen. The
Poisson calculation above treats pairs as independent and consequently
overstates power; the effective independent sample is materially smaller
and should be reduced to one representative per pedigree before
testing.
Run a matched-baseline arm. Time decay is the
largest nuisance parameter and cannot be estimated well from 19 pairs.
Running the England_CA_EBA arm simultaneously against date-matched
continental candidates makes decay common to both arms and cancels it in
the ratio. Candidates already present in the table, with median
dates:
| MN_Wartberg |
26 |
5140 |
| France_MontAime |
5 |
5162 |
| Ireland_MN |
8 |
5410 |
| MN_Hazendonk |
2 |
5470 |
| MN_Tiel |
2 |
5650 |
| Czechia_C_Baalberge |
7 |
5850 |
| France_N |
18 |
6550 |
Ireland_MN and MN_Wartberg are the best-matched to England_N’s median
of about 5500 BP. France_N at 6550 BP is a poor baseline and
Denmark_SouthScandinavia_LN at 4124 BP is too late.
Relax the coverage threshold. Only 12 of the 39
England_CA_EBA individuals and 6 of the 27 England_N individuals appear
in Supplementary Table 14 under the external group mapping; the table’s
own labels raise this to 11 and 19. Either way, roughly two-thirds of
the relevant individuals are excluded by whatever coverage criterion was
applied. The power calculation above shows this is the difference
between a decisive test and an inconclusive one.
Caveats on the calculation. The linear scaling of
detection rate in the ancestry fraction is an approximation that ignores
the distribution of segment lengths contributed by a minority ancestry
component, which will be shifted downward relative to a full-ancestry
comparison and so will lose disproportionately at a fixed 12 cM
threshold. The benchmark rate itself rests on 30 detections. And the
Poisson independence assumption is violated by relatedness in both arms.
Taken together these push the true power below the tabulated figures,
which is why the full-group coverage matters rather than being a
refinement.
All figures in this paper are produced by the accompanying script
reproduce.py (see Data and code availability),
which takes the three published supplementary workbooks as input and
prints every number in the order it appears here. The random seed for
the censoring simulation is fixed at 20260802; simulation figures are
stable to the second decimal place across seeds.
Required input files:
Booth et al. 2021 Supplementary Table 1 (Cambridge Core,
supplementary material to doi:10.1017/S0959774321000019)
Olalde et al. 2018 Supplementary Tables (Nature 555,
doi:10.1038/nature25738)
Olalde et al. 2026 Supplementary Tables (Nature,
doi:10.1038/s41586-026-10111-8)
Dependencies: Python 3, numpy, pandas, scipy, openpyxl.
Sources
Booth, T.J., Brück, J., Brace, S. & Barnes, I. 2021. Tales from
the supplementary information: ancestry change in Chalcolithic–Early
Bronze Age Britain was gradual with varied kinship organization.
Cambridge Archaeological Journal 31(3): 379–400.
doi:10.1017/S0959774321000019.
Harney, É., Patterson, N., Reich, D. & Wakeley, J. 2021.
Assessing the performance of qpAdm: a statistical tool for studying
population admixture. Genetics 217(4): iyaa045.
doi:10.1093/genetics/iyaa045.
Maier, R., Flegontov, P., Flegontova, O., Işıldak, U., Changmai, P.
& Reich, D. 2023. On the limits of fitting complex models of
population history to f-statistics. eLife 12: e85492.
doi:10.7554/eLife.85492.
Olalde, I., Brace, S., Allentoft, M.E. et al. 2018. The
Beaker phenomenon and the genomic transformation of northwest Europe.
Nature 555: 190–196. doi:10.1038/nature25738.
Olalde, I., Altena, E., Bourgeois, Q. et al. 2026. Lasting
Lower Rhine–Meuse forager ancestry shaped Bell Beaker expansion.
Nature 652: 938–946. doi:10.1038/s41586-026-10111-8.
Methodological background on qpAdm behaviour, model rejection and
rotating source analysis is not cited above because none of the
calculations here depend on it, but readers evaluating the
degrees-of-freedom convention in Appendix A and the interpretation of
non-rejection in §8 should consult Harney et al. 2021 and Maier
et al. 2023.
Changes from the 2 August
draft
New §2, “The estimand, stated precisely.” The
paper previously moved between two quantities — the size of the residue
and its provenance — without naming the second. It is now defined as β,
the proportion of the second-source component deriving from populations
resident in Britain before c. 2450 BC. Sections 2 to 11 of the
earlier draft are renumbered 3 to 12.
§9, the outliers (was §8). The earlier text
read: “those four individuals were the entirety of the Beaker-period
signal, and they survive independent testing with a proper Rhine–Meuse
proxy.” That sentence conflated measurement with attribution. The
magnitude of the outliers’ Neolithic-related component is confirmed; its
source is subject to exactly the same non-identifiability as
the group-level residue, and arguably more visibly so, since Appendix
D.2 puts England_BB_highEEF’s hunter-gatherer ratio at 0.239, inside the
continental cluster and within the individual scatter of England_N. The
paper cannot deny at eight per cent what it asserts at twenty-seven.
Corrected.
§10, the reconciliation (was §9). The
description of the Beaker phase carried the same error and has been
amended. A closing passage now sets out the three mechanisms that would
produce the observed residue with β = 0 — founder sampling, continental
top-up and proxy error — and notes that the temporal gradient of §6
points most naturally at the second, which is the reading under which
the interpretive weight placed on the rising residue collapses
entirely.
Appendix F is now Appendix E. The earlier draft
ran A, B, C, D, F.
Appendix D.3, IBD coverage. The draft gave two
different sets of counts for the same quantity — 6 of 27 and 12 of 39 in
D.3, against 19 and 11 in F.1 — without explaining that these come from
two different mappings of the table’s identifiers. Both are now given at
first mention, with the discrepancy explained; on either count roughly
two-thirds of the relevant individuals are absent.
Appendix A, Table A2. The column headed “df +
(α/SE)²” did not describe the quantity actually tabulated. κ is computed
as (χ² − df)/(α/SE)²; the column now shows (α/SE)² and the header is
correct. The values are unchanged and the derived bound of 3.46–3.75 per
cent is unaffected.
Bullet formatting in the Limitations and Sources lists, which had
collapsed on the earlier post.
Nothing in the numerical results has changed. Sections 3 to 8, and
Appendices B and C, are as posted.