Establishing the birth family of Jane Feeney: A proof statement for genetic genealogists
Using Autosomal DNA evidence at scale
Scope and purpose
This post is intentionally written as a proof statement.
Its purpose is to set out, in a concise and methodologically explicit form, the reasoning by which the birth family of Jane Feeney has been identified using autosomal DNA evidence derived exclusively from AncestryDNA, together with relevant documentary sources, and to explain why chromosome-level or segment triangulation analysis is not required to meet the standard of proof in this case.
It is not a full presentation of the underlying evidence.
The complete documentary record, detailed match analysis, descendant-line structures, and supporting tables are presented in a companion post:- When DNA changed Jane Feeney's story
That longer post should be read as the evidentiary foundation for the conclusions summarised here. This proof statement draws directly from that material, but is structured for a different purpose: to address questions of methodological sufficiency and standards of proof when working within the analytical framework provided by AncestryDNA in 2025.
Readers seeking individual match lists, centimorgan values, descendant charts, or documentary transcriptions are directed to the companion post. What follows is therefore an overview of conclusions and reasoning, not a substitute for the underlying data.
Research question
Can the birth family of Jane Feeney, who arrived in New South Wales aboard The Digby in 1849, be reliably identified using total shared autosomal DNA evidence and shared-match analysis from AncestryDNA, in the absence of chromosome browser or segment data?
Background
Jane Feeney arrived in Sydney on 4 April 1849 as part of the Earl Grey Famine Orphan Scheme. She was described as an “orphan” on immigration records, and for many years was assumed to have arrived in Australia without surviving parents or siblings.
Traditional documentary research established Jane’s later life in New South Wales — her marriages, children, residence, and death — but did not, on its own, identify her parents with confidence. Multiple hypotheses were considered over time, but none could be resolved definitively on documentary evidence alone.
This research therefore turned to autosomal DNA evidence, assessed entirely within the AncestryDNA environment, which reports total shared DNA (centimorgans) and provides shared-match and clustering tools, but does not provide a chromosome browser or segment-level data.
Evidence considered
The evidence used in this proof falls into two categories:
Autosomal DNA evidence from AncestryDNA, consisting of reported total shared centimorgans and shared-match relationships across multiple testers.
Documentary evidence, including immigration records, civil registrations, and contemporaneous correspondence.
No chromosome browser data, segment maps, or external triangulation tools were used or required.
Nature and strength of the Autosomal DNA evidence
The autosomal DNA evidence comprises:
Multiple testers descending independently from Jane Feeney, through different children.
Multiple testers descending independently from Edward Feeney and Thomas Feeney, who arrived in Australia in 1843.
A substantial number of shared matches linking these descendant groups.
Consistent shared-match clustering observed across all tested descendants of Jane Feeney.
All DNA comparisons are based on total shared autosomal DNA, as reported by AncestryDNA, and on the presence or absence of shared matches between testers.
These matches:
Occur across multiple independent descendant lines;
Fall within expected centimorgan ranges for the hypothesised relationships;
Are recurrent and internally consistent across different testers;
Form a coherent shared-match cluster that excludes unrelated families.
This conclusion is not derived from a small number of isolated matches. It reflects a stable autosomal signal, observable only because of the size of the AncestryDNA database and the number of tested descendants now available.
Identification of the Feeney sibling group
Within AncestryDNA, descendants of Jane Feeney consistently share autosomal DNA with descendants of:
Edward Feeney, who arrived in New South Wales in 1843 and married Margaret McCabe in 1853; and
Thomas Feeney, who also arrived in 1843 and married Julia Cooke in 1858.
Descendants of Edward and Thomas Feeney also share autosomal DNA with each other at levels consistent with a sibling relationship.
All tested descendants of Jane Feeney fall within the same shared-match network as the descendants of Edward and Thomas. No alternative Feeney family produces a comparable pattern of shared matches.
Within the AncestryDNA framework, this pattern can only be explained if Jane, Edward, and Thomas were children of the same parental couple.
Why chromosome-level or segment analysis is not required
AncestryDNA does not provide a chromosome browser or segment-level data. Consequently, this proof relies exclusively on:
Total shared autosomal DNA (centimorgans), and
Shared-match relationships at scale.
Historically, the absence of segment data was viewed as a limitation requiring external triangulation. That assumption reflected an earlier period when:
Databases were smaller;
Fewer descendants were tested;
Shared-match tools were limited or unavailable;
Conclusions often rested on a small number of matches.
That context no longer applies.
In this case, sufficiency is achieved through:
Repetition of the same shared-match structure across many independent descendant lines;
Consistency of total shared DNA signals within expected ranges;
Convergence of evidence across multiple testers and family branches;
Absence of competing shared-match clusters that could explain the observed pattern.
When dozens of testers independently reproduce the same shared-match configuration within AncestryDNA, segment triangulation becomes confirmatory rather than discriminative. It does not change the conclusion reached from the autosomal evidence already available.
Within the analytical constraints of AncestryDNA, the evidentiary threshold is met before chromosome level analysis becomes necessary.
Documentary corroboration
The autosomal DNA evidence aligns with, and is reinforced by, documentary material, including:
An 1850 Immigration Department letter recording Jane Feeney of Sydney making enquiries regarding her daughter who arrived per The Digby.
The earlier arrival of Edward and Thomas Feeney, consistent with older siblings migrating ahead of a younger sister.
Naming patterns among Jane Feeney’s children reflecting close familial connections to the Feeney sibling group.
The absence of documentary or genetic evidence supporting a competing Feeney family explanation.
Immigration records for Jane Feeney identify her parents as William and Jane Feeney, both recorded as deceased at the time of her arrival. Later New South Wales civil registrations also name parents, but these details are inconsistent and were supplied decades after the events concerned, limiting their evidentiary weight.
In contrast, the documentary records of Edward and Thomas Feeney consistently identify their parents as Edward Feeney and Jane Baker across multiple independent registrations. This consistency establishes a parental framework for that sibling group. Within that framework, it is the autosomal DNA evidence — assessed at scale and across multiple independent descendant lines — that resolves Jane Feeney’s placement within the Feeney family and supports her identification as a sibling of Edward and Thomas Feeney, and therefore as a child of Edward Feeney and Jane Baker.
Conclusion
The autosomal DNA evidence derived exclusively from AncestryDNA establishes, to a high degree of confidence, that Jane Feeney was a daughter of Edward Feeney and Jane Feeney (née Baker), and a sibling of Edward and Thomas Feeney who arrived earlier in New South Wales.
This conclusion is supported by:
Multiple independent descendant lines;
Recurrent shared-match patterns observed within AncestryDNA;
Total shared centimorgan values consistent with the hypothesised relationships;
Absence of plausible alternative explanations.
In this case, chromosome-level or segment triangulation analysis is not required to meet the standard of proof. The conclusion rests on the collective behaviour of autosomal DNA at scale within a single large database, rather than on segment-level confirmation.
Methodological takeaway
This case illustrates a key shift in modern genetic genealogy practice:-
When working within a large, mature database such as AncestryDNA, repeated and consistent shared-match patterns across many independent descendant lines can meet the standard of proof using total shared autosomal DNA alone.
This represents not a relaxation of standards, but an adaptation of methodology to scale and database architecture.