DNA Evidence Analysis
DNA testing has become a powerful tool for genealogical research, but interpreting genetic evidence requires careful attention to match levels, testing limitations, and the distinction between correlation and proof. This analysis examines the DNA evidence connecting four families who married in Donaghmoyne parish between 1841 and 1858.
The evidence varies significantly across the network. Some connections are supported by strong internal matches that confirm documented relationships. Others rest on cross-network matches at threshold levels that suggest but do not prove biological connections. This page presents what we know, what we suspect, and where the evidence remains inconclusive.
Understanding DNA Match Levels
Strong matches (100+ cM): Reliably indicate a biological relationship, typically within 4–5 generations. These matches are almost certainly "identical by descent" (IBD)—inherited from a common ancestor.
Moderate matches (30–99 cM): Likely indicate a relationship, but the common ancestor may be 5–7 generations back. Most matches in this range are IBD, though some smaller segments may be coincidental.
Threshold matches (15–29 cM): Require careful interpretation. While they can represent distant cousin relationships, matches in this range can also occur by chance between unrelated individuals, especially when only one segment is shared.
Weak matches (8–14 cM): At the edge of significance. These matches frequently occur by chance ("identical by chance" or IBC) and should not be considered evidence of relationship without corroborating factors such as shared matches, geographic clustering, or documentary evidence.
The Four DNA Clusters
Current testing status and internal match strength for each family line
Chicago Cluster
Testing Status
4 testers, all descending from Mary Ann Hamall Byron (Owen's sister). Three testers are a father and his two daughters—effectively two independent data points. 5 testers descend from Owen Hamall's direct line, but all are siblings (children of Thomas Kenny Hamall), functioning as a single data point. The genealogical bottleneck remains: no cousins exist within the Chicago line for triangulation. (the Thomas Kenny line has no 1st, 2nd, or 3rd cousins to compare).
Critical Limitation
These four testers do not share DNA with the other Hamill lines (Wisconsin, Joliet, Montana/Missouri). However, they do share matches with a McMahon cluster—suggesting the genetic connections may trace through Mary McMahon rather than the Hamill line.
| Testers | 4 |
| Independent lines | 1 (Mary Ann Byron) |
| Internal matches | 15–20 cM range |
| Cross-network | None confirmed |
Wisconsin Cluster
Testing Status
Multiple testers across several children's lines. Strong internal matches confirm common descent from Owen and Ann. Descendants spread from Wisconsin to Nebraska.
Internal Evidence
Internal matches of 52–74 cM between descendants of different children confirm the documented family structure. This cluster has the most robust internal validation after the James/Ann Gartlan line.
Cross-Network Matches
Matches to Chicago line: 21–34 cM (23andMe), 10–17 cM (Ancestry). These levels are suggestive of a relationship but not conclusive. The brother hypothesis (Owen and Henry as siblings) remains unproven.
| Testers | 8+ |
| Children's lines represented | 3–4 |
| Internal matches | 52–74 cM |
| Cross-network (Chicago) | 10–34 cM |
Joliet Cluster
Testing Status
9 testers across 3 children's lines (Mary Ann McCanna Kelly, Nellie McCanna Sheridan, Frank McCanna). Strong internal matches confirm the documented sibling relationships.
Internal Evidence
Internal matches of 27–67 cM between descendants of different children validate the family structure. The McCanna family is well-documented in Joliet records.
Cross-Network Matches
Matches to Chicago line: 8–15 cM—at threshold of significance. New discovery: D.G. (Catherine Hammill Linstead descendant) shows 28–32 cM to Nellie McCanna descendants, a more significant connection requiring further investigation.
| Testers | 9 |
| Children's lines represented | 3 |
| Internal matches | 27–67 cM |
| Cross-network (Chicago) | 8–15 cM |
Montana/Missouri Cluster
Testing Status
14 testers across 5 children's lines: James (Montana), Patrick (Missouri), Henry (Missouri), Anna (Ireland), Bridget (Ireland). The most comprehensively tested cluster with the strongest internal evidence.
Internal Evidence
PROVEN: Documentary evidence (including Peter Hamill's 1949 death certificate naming both parents) combined with strong DNA matches (23–228 cM between children's lines, 1627–3463 cM between close relatives) definitively establishes the sibling relationships.
Cross-Network Matches
Connection to Chicago line is indirect—one promising match identified on another platform. Shared matches through other clusters point to common Monaghan ancestry. The exact relationship remains under investigation.
| Testers | 14 |
| Children's lines represented | 5 |
| Internal matches | 23–228 cM |
| Cross-network (Chicago) | Indirect only |
DNA Match Matrices
Visual evidence of shared DNA across the network
The following matrices show shared centimorgans (cM) between tested descendants. Names have been anonymized to protect privacy. The ancestor from whom each tester descends is noted in parentheses. Higher cM values indicate closer relationships—color intensity reflects match strength.
Chicago ↔ Wisconsin: 23andMe Evidence
M.H.M. (Chicago) matches descendants of three different children of Owen Hammel & Ann King
KEY FINDING — 23ANDME
M.H.M. (Chicago line) shares 21–34 cM with descendants of three different children of Owen Hammel & Ann King (Wisconsin): Anna Hammel Engel, Mary E Hammel Bucklin, and Henry Patrick Hammel.
This pattern—matching multiple descendants across different branches of the same family—is consistent with what we would expect if Owen Hammel (Wisconsin) and Henry Hamall (Chicago) were brothers. The match levels of 21–34 cM are consistent with 3rd cousins once removed to 4th cousins, the expected relationship if the common ancestors were brothers. However, matches at these levels can also occur by chance, so this evidence is suggestive rather than conclusive.
Chicago ↔ Wisconsin: Ancestry Confirmation
Cross-platform verification of the Chicago-Wisconsin connection
KEY FINDING — ANCESTRY
On Ancestry, M.H.M. (Chicago) matches Wisconsin Hammel descendants at 10–17 cM—lower than 23andMe but still consistent across multiple testers from different branches. The consistency of matches across both platforms strengthens the hypothesis.
The high matches within the Wisconsin line (such as 206 cM between M.G. and S.R., both descended from Mary E Hammel Bucklin) confirm that testers correctly descend from the documented ancestors. The cross-network matches to Chicago, while lower, appear across multiple independent lines.
Owen Hammel & Ann King: 23andMe Internal Matches
Strong internal matches confirm documented family structure
| Tester (Ancestor) | M.H.M.Chicago | R.V.E.Anna Engel | L.L.Mary Bucklin | L.F.Henry Patrick | C.F.Gartlan* |
|---|---|---|---|---|---|
| M.H.M.Henry Hamall & Mary McMahon (Chicago) | — | 34 | 33 | 21 | 23 |
| R.V.E.Anna Hammel Engel (Wisconsin) | 34 | — | 74 | 26 | 16 |
| L.L.Mary E Hammel Bucklin (Wisconsin) | 33 | 74 | — | 52 | 16 |
| L.F.Henry Patrick Hammel (Wisconsin) | 21 | 26 | 52 | — | 0 |
| C.F.James Hamill & Ann Gartlan (Donaghmoyne)* | 23 | 16 | 16 | 0 | — |
Key Finding — Wisconsin Line Validation
Internal matches between Wisconsin descendants (52–74 cM between children of different Owen/Ann children) confirm the documented family structure. These match levels are exactly what we would expect for the generational distance involved.
The inclusion of C.F. (James Hamill & Ann Gartlan descendant) shows matches of 16–23 cM to Chicago and Wisconsin testers—suggesting a more distant connection to the Donaghmoyne network, though at threshold levels requiring careful interpretation.
Owen Hammel & Ann King: Full Network View (Ancestry)
Comprehensive matrix including Wisconsin, Chicago, and McCanna descendants
| Tester (Ancestor) | M.H.M.Chicago | T.L.Anna Engel | C.L.Henry Patrick | M.G.Mary Bucklin | S.R.Mary Bucklin | T.L.2Henry Patrick | J.C.Mary Bucklin | J.Y.Mary Bucklin | M.S.McCanna* | B.W.Mary Bucklin | C.L.2Mary Bucklin | K.B.McCanna* | H.C.McCanna* | J.R.McCanna* |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| M.H.M.Henry Hamall & Mary McMahon (Chicago) | — | 14 | 17 | 17 | 10 | 15 | 14 | 15 | 13 | 13 | 10 | 11 | 8 | 15 |
| T.L.Anna Hammel Engel (Wisconsin) | 14 | — | 35 | 55 | 33 | 23 | 24 | 22 | 0 | 0 | 0 | 0 | 0 | 0 |
| C.L.Henry Patrick Hammel (Wisconsin) | 17 | 35 | — | 0 | 46 | 3477 | 0 | 0 | 0 | 0 | 0 | 27 | 25 | 0 |
| M.G.Mary E Hammel Bucklin (Wisconsin) | 17 | 55 | 0 | — | 206 | 0 | 1604 | 3476 | 35 | 1889 | 293 | 0 | 0 | 0 |
| S.R.Mary E Hammel Bucklin (Wisconsin) | 10 | 33 | 46 | 206 | — | 0 | 38 | 52 | 49 | 131 | 2785 | 47 | 0 | 0 |
| T.L.2Henry Patrick Hammel (Wisconsin) | 15 | 23 | 3477 | 0 | 0 | — | 0 | 0 | 0 | 0 | 0 | 0 | 26 | 0 |
| J.C.Mary E Hammel Bucklin (Wisconsin) | 14 | 24 | 0 | 1604 | 38 | 0 | — | 810 | 0 | 520 | 167 | 0 | 0 | 0 |
| J.Y.Mary E Hammel Bucklin (Wisconsin) | 15 | 22 | 0 | 3476 | 52 | 0 | 810 | — | 0 | 1764 | 133 | 0 | 0 | 0 |
| M.S.Susan Hamill & Charles McCanna* | 13 | 0 | 0 | 35 | 49 | 0 | 0 | 0 | — | 22 | 60 | 283 | 140 | 369 |
| B.W.Mary E Hammel Bucklin (Wisconsin) | 13 | 0 | 0 | 1889 | 131 | 0 | 520 | 1764 | 22 | — | 163 | 0 | 0 | 0 |
| C.L.2Mary E Hammel Bucklin (Wisconsin) | 10 | 0 | 0 | 293 | 2785 | 0 | 167 | 133 | 60 | 163 | — | 0 | 0 | 0 |
| K.B.Susan Hamill & Charles McCanna* | 11 | 0 | 27 | 0 | 47 | 0 | 0 | 0 | 283 | 0 | 0 | — | 143 | 317 |
| H.C.Susan Hamill & Charles McCanna* | 8 | 0 | 25 | 0 | 0 | 26 | 0 | 0 | 140 | 0 | 0 | 143 | — | 114 |
| J.R.Susan Hamill & Charles McCanna* | 15 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 369 | 0 | 0 | 317 | 114 | — |
Key Finding — Cross-Network Patterns
This comprehensive matrix reveals the complexity of the network. Strong internal matches within the Wisconsin line (1604–3477 cM for close relatives, 131–293 cM for more distant cousins) confirm documented relationships.
Cross-network patterns are more varied: Chicago (M.H.M.) shows consistent 8–17 cM matches to Wisconsin testers, while McCanna descendants (M.S., K.B., H.C., J.R.) show sporadic matches. The pattern suggests possible relationships but at levels requiring segment analysis for confirmation.
Susan Hamill & Charles McCanna: Verified Matches
Internal McCanna matches plus cross-network connections to Chicago
| Tester (Ancestor) | M.H.M.Chicago | C.H.M.Chicago | M.S.Nellie | J.G.Susan | S.M.Mary Anna | S.T.Mary Anna | L.M.Mary Anna | S.E.Nellie | J.R.Nellie | K.B.Nellie | H.C.Frank |
|---|---|---|---|---|---|---|---|---|---|---|---|
| M.H.M.Henry Hamall & Mary McMahon (Chicago) | — | 2767 | 13 | 8 | 10 | 8 | 8 | 15 | 15 | 11 | 8 |
| C.H.M.Henry Hamall & Mary McMahon (Chicago) | 2767 | — | 23 | 14 | 11 | 0 | 0 | 17 | 17 | 11 | 12 |
| M.S.Ellen B "Nellie" McCanna Sheridan | 13 | 23 | — | 3440 | 67 | 51 | 50 | 253 | 369 | 283 | 140 |
| J.G.Susan Hamill & Charles McCanna | 8 | 14 | 3440 | — | 40 | 37 | 33 | 139 | 205 | 140 | 41 |
| S.M.Mary Anna McCanna Kelly | 10 | 11 | 67 | 40 | — | 2700 | 1864 | 36 | 27 | 0 | 37 |
| S.T.Mary Anna McCanna Kelly | 8 | 0 | 51 | 37 | 2700 | — | 3458 | 49 | 47 | 0 | 0 |
| L.M.Mary Anna McCanna Kelly | 8 | 0 | 50 | 33 | 1864 | 3458 | — | 0 | 37 | 0 | 0 |
| S.E.Ellen B "Nellie" McCanna Sheridan | 15 | 17 | 253 | 139 | 36 | 49 | 0 | — | 3486 | 15 | 37 |
| J.R.Ellen B "Nellie" McCanna Sheridan | 15 | 17 | 369 | 205 | 27 | 47 | 37 | 3486 | — | 317 | 114 |
| K.B.Ellen B "Nellie" McCanna Sheridan | 11 | 11 | 283 | 140 | 0 | 0 | 0 | 15 | 317 | — | 143 |
| H.C.Frank Charles McCanna | 8 | 12 | 140 | 41 | 37 | 0 | 0 | 37 | 114 | 143 | — |
Key Finding — McCanna Network
Strong internal matches within the McCanna family (1864–3486 cM for close relatives, 27–369 cM for documented cousins across different children's lines) confirm the family structure. Three children's lines are represented: Mary Anna McCanna Kelly, Ellen B "Nellie" McCanna Sheridan, and Frank Charles McCanna.
Cross-network matches to Chicago (8–23 cM) are at threshold levels. The pattern suggests Susan Hamill may have been related to Henry Hamall, but the match levels are too low for confident conclusions without segment triangulation.
Cross-Network Match Analysis
What connects these four families—and what doesn't
The central question of this research is whether the four couples who married in Donaghmoyne parish were biologically related. The cross-network DNA evidence is mixed:
| Connection | Match Level | Status | Interpretation |
|---|---|---|---|
| James/Gartlan Internal | 23–228 cM | PROVEN | Sibling relationship confirmed by DNA + documents |
| Owen/King Internal | 52–74 cM | PROVEN | Common descent from Owen & Ann confirmed |
| McCanna Internal | 27–67 cM | PROVEN | Common descent from Charles & Susan confirmed |
| Chicago ↔ Wisconsin | 10–34 cM | SUGGESTIVE | Consistent with brother hypothesis but not proof |
| Chicago ↔ Joliet | 8–15 cM | EXPLORING | At threshold; could be coincidental |
| Wisconsin ↔ Joliet | Sporadic | EXPLORING | Some matches identified; pattern unclear |
| Chicago ↔ Montana/Missouri | Indirect | INDIRECT | One promising match; shared matches suggest connection |
| Chicago ↔ McMahon Cluster | 15–20 cM | NEW FINDING | May explain Chicago matches; requires investigation |
The McMahon Question
A significant complication has emerged: the four Chicago testers (descendants of Mary Ann Hamall Byron) do not share DNA with the other Hamill lines, but they do share matches with a newly identified McMahon cluster. This raises the possibility that cross-network matches previously attributed to Hamill connections may actually trace through Mary McMahon (Henry Hamall's wife) rather than through a Hamill sibling relationship. This finding does not disprove the brother hypothesis, but it introduces an alternative explanation for some of the genetic patterns we observe.
Key Findings & Limitations
What the DNA evidence tells us—and what it doesn't
James/Ann Gartlan Siblings: CONFIRMED
The sibling relationship between James (Montana), Patrick (Missouri), Henry (Missouri), Anna (Ireland), and Bridget (Ireland) is proven through documentary evidence and validated by strong DNA matches (23–228 cM). This is the anchor point of the network.
Internal Clusters: VALIDATED
Each of the four clusters shows internal DNA matches that confirm the documented family structures. Descendants of the same couple share DNA at expected levels for their generational distance.
Brother Hypothesis: UNPROVEN
The hypothesis that Henry Hamall and Owen Hammel were brothers is supported by circumstantial evidence (same parish, naming patterns) and suggestive DNA matches (10–34 cM), but match levels are too low for definitive proof. The McMahon cluster finding adds further uncertainty.
Cross-Network Connections: THRESHOLD
Most cross-network matches fall in the 8–34 cM range—levels that can occur by chance. Without segment triangulation or additional evidence, these matches suggest but do not prove biological relationships between the four founding couples.
McMahon Connection: EMERGING
The Chicago testers' matches to a McMahon cluster may be more significant than their matches to other Hamill lines. This could indicate that Mary McMahon's ancestry provides an alternative pathway for some of the genetic connections observed.
Chicago Bottleneck: LIMITING
The extreme genealogical bottleneck in the Chicago Hamall line (only one path to testers, no cousin matches available) severely limits our ability to triangulate relationships. Y-DNA testing may be the only way to definitively establish Hamill paternal connections.
Research Still Needed
- Segment Triangulation: Analyze chromosome browsers to determine if cross-network matches share the same DNA segments (true IBD) or occur on different segments (potential IBC). This is critical for evaluating the 8–34 cM matches.
- Y-DNA Testing: Big Y-700 tests from male-line Hamill/Hamall/Hammel descendants could definitively establish or disprove the brother hypothesis by tracing paternal lineage beyond autosomal DNA's reach.
- McMahon Cluster Investigation: Further analysis of the McMahon matches to determine if they represent a distinct ancestral line or overlap with the Hamill network.
- Additional Testers: More testers from underrepresented lines—particularly the Owen Hammel/Wisconsin line and any surviving Hamill male lines—would strengthen the analysis.
- Catherine Hammill Linstead Connection: The D.G. match (28–32 cM to McCanna descendants) warrants investigation as a potentially more significant cross-network link.
Summary Assessment
The DNA evidence supports the existence of a "Donaghmoyne Network" but does not yet prove it. The strongest evidence confirms the James Hamill & Ann Gartlan sibling group. The weakest evidence concerns the connection between the Chicago Hamall line and the broader network—complicated by the genealogical bottleneck and the emerging McMahon cluster finding.
The brother hypothesis (Henry, Owen, and James as siblings) remains a reasonable working theory supported by circumstantial evidence, but definitive proof will likely require Y-DNA testing to trace paternal lineage beyond the limits of autosomal DNA.
This analysis represents research in progress. Conclusions are subject to revision as new evidence emerges.