But First, What Does DNA Reveal?

 While I wait for record look-ups from Osborne County, Kansas, and the Missouri State Archives that should give more insight about my 2nd Great Grandmother Estella Cordelia (Davis) Smith and the various names she went by, I thought I'd talk about what the DNA reveals about Harrison Blacketer and Martha Jane Smith.

TL;DR (Too long; Didn't read)

It seems to confirm the relationships.😅 I mean, given all the secrecy about James's out-of-wedlock birth, one might have thought he possibly had had another father, right? Below is my analysis from my Starting Point Analysis Report for Martha Jane Smith. However, parts of it are anonymized to protect privacy of living individuals. It is a little dense, but I tried to break things down as much as possible.

Autosomal DNA (atDNA)

Genetic Genealogy testing can help to identify relationships and specific ancestors who have not been added to the family tree and also confirm already-known relationships. It can also reveal clues and family trees (that need to be verified), which can provide new avenues for research. However, it cannot tell us how family lines are connected to each other, and that is why documentary research is also needed. They work hand-in-hand.

Additionally, tests for autosomal DNA (abbreviated as atDNA), like the AncestryDNA tests considered in this analysis, analyze all a person's atDNA. Therefore, it is possible to locate matches to any ancestor across many different lines in a person's family tree. This is because atDNA is randomly inherited from one's parents. (1) It is most useful for exploring a person's more recent ancestors, usually within five generations. (2)

The measurement for atDNA shared between two individuals is called a centimorgan, usually abbreviated to cM. Everyone inherits approximately 50 percent of their atDNA from each parent. That 50 percent includes about 25 percent from each grandparent, about 12.5 percent from each great-grandparent, and so on and so forth. (3) Based on those estimates, different genetic relationships will share predictable ranges of centimorgans. However, as the relationships get farther away from a parent-child relationship, the more the predicted ranges overlap. Using mathematical probabilities, hypotheses can be created that give the best possible likelihood of relationships based on groups of atDNA test results when they are compared to each other. Further, calculating statistics for each relationship and comparing it to the average for each relationship can lend more weight to the evaluation (standard deviation).

Blacketer-Smith Autosomal DNA (atDNA) Descendants

There are ten identified shared atDNA matches at AncestryDNA who descend from James Wesley Blacketer and Mary Alice Truitt. There are more who are identified, but some are from younger generations and are represented by older testers. Others have tested at 23andme, but the rest of the testers did not so detailed comparisons are not available for all testers with each other. There are also three identified adoptees who were not selected for this analysis.

There is only one identified atDNA shared match descendant of James Wesley Blacketer's sister Mildred I. (Blacketer) Black, this test-taker has since passed away, but left a public family tree attached to his AncestryDNA kit. While more descendant atDNA testers who descend from James's two siblings would be preferable, this one atDNA test-taker is rather close relationship-wise to the descendants of James Wesley Blacketer and that improves analysis. Hopefully more will test in the future! More data points are always preferable.

Thus, there are a total of eleven descendants of James's and Mildred's parents, Harrison Blacketer and Martha Jane Smith, who tested their atDNA at AncestryDNA who were selected for this analysis. Their places in the Blacketer—Smith family tree are depicted in Figure 1 below. For privacy, the documentary proof for each relationship will not be published. However, it has been documented. No one is related to each other in more than one way. This is important to note because if people are related to each other in more than one way, they would share more autosomal DNA than expected for their known or documented relationship. (4). To maintain privacy, living test-takers are anonymized except for myself. Three of the test-takers have passed away.

Figure 1: Blacketer-Smith atDNA Descendant Chart

Standard Deviation Analysis of atDNA Shared Matches

But first, here are some definitions to help understand my analysis.

Glossary:

Standard Deviation: the symbol for Standard Deviation is σ. The standard deviation is a statistical measure of data's spread from its average. A low standard deviation indicates the data is tightly clustered around the average. A high standard deviation indicates the data is spread out over a range. Basically, the tighter the data around the average, the better. (5)

cM: abbreviation of Centimorgan which is the unit of measure for autosomal DNA (atDNA). (6)

Sibs: abbreviation for Siblings; two people who share both parents.

1C: abbreviation for 1st Cousin; the child of one's aunt or uncle.

1C1R: abbreviation for a 1st Cousin Once Removed; in this analysis, the first cousin once removed is a child of one's first cousin.

2C: abbreviation for 2nd Cousin; the grandchild of one's great aunt or uncle.

2C1R: abbreviation for a 2nd Cousin Once Removed; in this analysis, a second cousin once removed is a child of one's second cousin.

Grand Aunt/Uncle/Niece/Nephew: the term "grand" is interchangeable with "great." A grand (or great) aunt or uncle is a sister or brother of one's grandparent. Likewise, a grand (or great) niece or nephew is a grandchild of one's sibling. (7)

The Shared Centimorgan Project provides the calculated average of shared centimorgans of autosomal DNA (atDNA) for each specific relationship based on crowd-sourced data. The project also provides a range of shared atDNA centimorgans for each relationship. As of March 202, there have been more than 60,000 submissions to the project. (8) The more submissions there are, the closer to accuracy the data analysis can be. Having all this data allows one to make sure the shared atDNA supports the known or supposed relationship with each match the DNA testing company provides for each test-taker.

Figure 2 below shows the relationships analyzed for this study as well as the average and range for each relationship. Siblings can share between 1613-3489 centimorgans (cM) with an average of 2613 cM. An aunt or uncle can share with their niece or nephew between 1201-2282 cM of atDNA wit h the average shared of 1741 cM. A grand (or great) aunt or uncle can share with their grand (or great) niece or nephew between 330-1467 cM with the average shared being 850 cM. First cousins can share between 396-1397 cM and an average of 433 cM with each other. First cousins once removed can share between 102-980 cM and an average of 433 cM. Second cousins can share between 41-592 cM with an average of 229 cM with each other. And second cousins once removed can share between 14-353 cM with an average of 122 cM. (9)

Figure 2: Relationships & the Correlating Average and Range in Centimorgans

All relationships proven in the documentary evidence are supported by the atDNA evidence analysis. Figure 3 below details all eleven Blacketer—Smith descendant atDNA test-takers, how much atDNA they share with each other shown in centimorgans (cM), the relationship between each other supported by documentary evidence, and the calculated standard deviation for each relationship.

While there are a few outliers—meaning some share more than 1 or less than -1 of atDNA with each other— none share more or less than the range of shared atDNA with each other. The outliers are those who share a little more or a little less atDNA due to the random inheritance of atDNA. (10) (These outliers are marked in bold black in the chart.) In fact, most of the atDNA test-takers share close to the average (smaller standard deviation) for each relationship which is strong supporting evidence for the relationships. (These are marked in bold green in the chart.)

Most importantly, 7 of the 10 test-takers who descend from James Wesley Blacketer share close to the average (lower standard deviation) of shared atDNA with the one descendant test-taker of James's sister Mildred, Gary Fred Moore, a.k.a., Test-Taker 11. The other 3 of the 10 share a little less atDNA but are still within the range for the given relationships. Notably the two oldest test-takers, Mary Ann (Blacketer) Halsell (Test-Taker 5) and Patrick Blacketer (Test-Taker 10), who are the closest in relationship to Gary Fred Moore (Test-Taker 11), share very close to the average for their relationship to him, first cousin once removed (1C1R), which makes sense. (These are marked in the yellow cells in the chart.) (11) 

Figure 3: Relationship and Standard Deviation Analysis

So, the autosomal DNA (atDNA) appears to support the documented relationships at this point. I cannot tell with this data if, say, one of Harrison's brothers or half-brothers fathered James. More data points (testers) would be helpful. And I do have more atDNA data to support earlier generations, but I'll share that later. That's enough math and science intersecting with family history for today, right?

~Caroline

Sources:

1. “Autosomal DNA,” FamilyTreeDNA ( https://help.familytreedna.com/hc/en-us/articles/4411196877327-Autosomal-DNA : accessed 25 September 2025).

2. “Autosomal DNA,” FamilyTreeDNA ( https://help.familytreedna.com/hc/en-us/articles/4411196877327-Autosomal-DNA : accessed 25 September 2025).

3. “Autosomal DNA,” FamilyTreeDNA ( https://help.familytreedna.com/hc/en-us/articles/4411196877327-Autosomal-DNA : accessed 25 September 2025).

4. For documentary proof for all relationships: Caroline M. Pointer, Starting Point Analysis Report for Martha Jane Smith, report to file, 29 August 2025, p. 75-77. For multiple relationships: Diana Elder, “Endogamy, Pedigree Collapse, and Multiple Relationships: What’s the Difference and Why Does it Matter?,” Family Locket, 2 September 2022, (https://familylocket.com/endogamy-pedigree-collapse-and-multiple-relationships-whats-the-difference-and-why-does-it-matter/ : accessed 25 September 2025).

5. Ed Williams, “Estimating Confidence Intervals in the Shared cM Project v4,” Counting Chromosomes: The Blog, 28 March 2020, (https://countingchromosomes.com/blog/75-estimating-confidence-intervals-in-the-shared-cm-project-v4 : accessed 25 September 2025).

6. Annelie Hansen, “Untangling the Centimorgans on Your DNA Test,” FamilySearch Blog, 6 April 2020, (https://www.familysearch.org/en/blog/centimorgan-chart-understanding-dna : accessed 25 September 2025).

7. Jessica Grimaud, “What Is a Second Cousin?–Cousin Relationships Explained,” FamilySearch Blog, 23 July 2019, (https://www.familysearch.org/en/blog/what-is-a-second-cousin : accessed 25 September 2025.

8. Blaine T. Bettinger, “Version 4.0! March 2020 Update to the Shared cM Project!,” The Genetic Genealogist, 27 March 2020, (https://thegeneticgenealogist.com/2020/03/27/version-4-0-march-2020-update-to-the-shared-cm-project/). 

9. Jonny Perl, The Shared cM Project 4.0 tool v4 (https://dnapainter.com/tools/sharedcmv4 : accessed 25 September 2025); citing Blaine T. Bettinger, The Shared cM Project.

10. “Autosomal DNA,” FamilyTreeDNA ( https://help.familytreedna.com/hc/en-us/articles/4411196877327-Autosomal-DNA : accessed 25 September 2025).

11. All atDNA comparisons were made at AncestryDNA using shared matches of shared matches. For detailed citations for each comparison, see: Caroline M. Pointer, Starting Point Analysis Report for Martha Jane Smith, report to file, 29 August 2025, p. 73-75.