Endogamy & Pile-up Region Log Excel Template
Endogamy & Pile-Up Region Log Template
Document recurring chromosome regions, endogamy patterns, and potential pile-up segments so you can interpret shared DNA matches with greater context and avoid relying on a single segment as proof of recent shared ancestry.
Preview of the Endogamy & Pile-Up Region Log spreadsheet.
In endogamous populations, people may share DNA through multiple ancestral paths. This can produce many matches and repeated segment patterns that are difficult to interpret using ordinary one-to-one match analysis.
A research log helps you document chromosome regions that appear repeatedly in your match data and record the evidence behind your interpretation. These regions can then be treated as contextual clues rather than automatically interpreted as evidence of a recent common ancestor.
What Is This Template?
The Endogamy & Pile-Up Region Log is a structured research worksheet for genealogists working with large numbers of DNA matches, endogamous populations, pedigree collapse, or recurring shared segments.
Instead of keeping chromosome coordinates and research observations scattered across notes, spreadsheets, or match profiles, you can maintain a central record of regions that deserve additional scrutiny.
Who Is This Template For?
This template is particularly useful for genealogists researching endogamous or historically isolated populations, researchers who work with chromosome browsers, and anyone who regularly encounters the same chromosome regions across many DNA matches.
Endogamy vs. Pile-Up Regions: What Is the Difference?
Endogamy
Endogamy occurs when people within a population or community repeatedly marry within the same population. Over generations, this can create multiple paths of relatedness between people and make DNA-match interpretation more complicated.
Pile-Up Regions
A pile-up region is a chromosome area that appears repeatedly among many matches. Such regions may be less informative for identifying a particular recent genealogical connection and should therefore be interpreted in the context of the population and the available evidence.
Why These Regions Matter in DNA Research
- They can help explain why a researcher has unusually large numbers of shared DNA matches.
- They provide useful context when comparing chromosome segments across multiple matches.
- They can help distinguish recurring population-level patterns from segments that deserve closer genealogical investigation.
- They create a documented research trail so you can review how a particular chromosome region was identified and interpreted.
- They are especially useful when working with communities affected by long-term endogamy or repeated pedigree collapse.
Pre-Formatted Columns Included
The spreadsheet is organized around the information you are most likely to need when documenting recurring chromosome regions.
- Chromosome Number — Record chromosome 1–22 or X.
- Pile-Up Start Coordinate — Store the beginning base-pair position of the documented region.
- Pile-Up End Coordinate — Record the ending base-pair position.
- Segment Length Range — Record the observed cM range associated with the region.
- Affected Matches & Frequency — Document how frequently the region appears in your research dataset.
- Population Context — Note the relevant island, valley, village, religious community, ethnic population, or other research context where appropriate.
- Filtering / Interpretation Strategy — Record the approach you use when evaluating matches that overlap the region.
- Research Notes & Verification Status — Record supporting evidence, open questions, sources, and whether the region has been independently reviewed.
Best Use Cases for This Template
- Documenting chromosome regions that repeatedly appear across many matches.
- Keeping a research log for DNA analysis in endogamous populations.
- Recording observations from chromosome-browser research.
- Comparing recurring segment patterns across multiple matches.
- Documenting pedigree-collapse or population-history context that may affect DNA-match interpretation.
- Creating a reference list that can be revisited when analyzing new matches from the same population or family network.
Important: A Pile-Up Region Is Not Automatically a False Match
A recurring chromosome region should not simply be labeled "irrelevant" or "false" because many people share it. The pattern may reflect complex population history, multiple ancestral paths, or other factors that require further investigation.
Likewise, there is no universal cM threshold that automatically removes endogamy from DNA-match analysis. Appropriate filters depend on the population, testing platform, relationship being investigated, and the rest of the available evidence.
Use this spreadsheet as a research and documentation tool rather than as a substitute for evaluating the complete evidence behind a DNA match.
Step-by-Step Research Workflow
Review chromosome-browser data and look for regions that appear repeatedly across a large number of matches.
Enter the chromosome number and approximate start and end coordinates in the spreadsheet.
Record how many matches you have observed in the region and note relevant population or family context.
When a new match overlaps a documented region, use the log as one piece of context rather than making an automatic relationship determination.
Compare the DNA evidence with shared matches, segment patterns, family trees, documentary records, and other relevant research.
Add new observations and record changes in your interpretation as your research develops.
Frequently Asked Questions
What is a pile-up region in DNA genealogy?
A pile-up region is a chromosome area that repeatedly appears among many DNA matches. Such regions can be less useful for identifying a specific recent genealogical relationship and should be interpreted alongside other evidence.
Why are pile-up regions important in endogamous populations?
Endogamy can create multiple paths of relatedness between individuals. As a result, researchers may see large numbers of matches and recurring chromosome segments that are difficult to interpret using ordinary match analysis alone.
Does a pile-up segment mean that the DNA match is false?
No. A recurring region does not automatically mean that a match is false or irrelevant. It indicates that the segment should be interpreted with additional population and genealogical context.
Should I use a fixed cM threshold for endogamous matches?
Not as a universal rule. The appropriate approach depends on the population, testing data, research question, and supporting evidence. A higher threshold may sometimes be useful, but it should be treated as a research strategy rather than a universal cutoff.
Can this template prove that a chromosome region is a pile-up?
The spreadsheet is a documentation tool, not a statistical test. It helps you organize observations and evidence so that you can evaluate recurring patterns more systematically.
Can I use this template with chromosome-browser data?
Yes. The chromosome and coordinate fields are designed to help you record observations from chromosome-browser analysis and related DNA tools.
Is this template useful outside of endogamous populations?
Yes. While it is particularly useful for endogamous research, the same type of log can help document recurring segment patterns in other datasets where a researcher wants to keep track of chromosome regions requiring additional scrutiny.
Can I combine this with chromosome mapping?
Yes. A pile-up log can provide contextual information while a chromosome mapping spreadsheet can help you organize segments associated with specific research hypotheses or ancestral lines.
Ready to Organize Your Endogamy Research?
Download the free Endogamy & Pile-Up Region Log and create a structured reference for recurring chromosome patterns in your DNA research.
📥 Download the Free TemplateDNA Academy - Quick Answers
What formats are your free templates available in?
Our templates are available as downloadable Excel/Google Sheets files (for digital tracking).
How do I use a research log effectively?
A research log helps you track which records you’ve searched, what you found, and what’s still missing. We recommend filling it out as you go, it prevents duplicate searches and helps you identify patterns. Our template includes columns for date, source, location, and findings.
Are the templates available in languages other than English?
Currently, our templates are in English only. We are exploring translations into Swedish, Spanish, and German based on user requests. If you need a specific language, contact us and we’ll prioritize it.