I Have My AncestryDNA Results. Now What?

A practical, step-by-step guide for Puerto Rican genealogists who have AncestryDNA results and are ready to put them to work.

Beginner

✓ Available

You Have Results. Now What?

Your AncestryDNA results arrived. The colorful ethnicity percentages are the first thing you see, and they are almost certainly not what you expected.

Set them aside for now.

The part of your results that will actually advance your genealogy research is not the ethnicity estimate. It is the match list: the hundreds or thousands of people who share measurable DNA with you and are almost certainly your relatives. Learning to read and use that list is what this guide is about.

This guide walks you through the five most important steps after your results arrive, explains what shared DNA measurements mean, and shows you when to connect DNA evidence back to your documentary research.

Step 1: Set Aside the Ethnicity Estimate (for Now)

AncestryDNA’s ethnicity estimate is a statistical comparison between your DNA and reference populations. It is genuinely interesting background context, but:

The Caribbean reference populations are smaller and less precise than European ones, which makes Puerto Rican estimates especially variable.
Your estimate may change significantly as AncestryDNA updates its reference databases, which they do regularly.
The percentages cannot tell you which ancestor was which ethnicity, or when any particular line arrived on the island.

Ethnicity estimates improve over time. Your match list does not change. Start with the match list.

You can return to the ethnicity estimate later, once you understand your family network better and have documentary evidence to compare it against. For now, navigate to DNA Matches in the AncestryDNA menu.

Step 2: Go to Your Match List

Your match list shows everyone in the AncestryDNA database who shares a measurable amount of DNA with you. Depending on when you tested, this may be several hundred people or several thousand.

AncestryDNA sorts matches by the amount of DNA shared, measured in centimorgans (cM). A centimorgan is a unit of genetic distance: the higher the number, the more DNA you share, and generally the more recently you and that person share a common ancestor.

Understanding the cM Table

This table shows typical cM ranges for different relationships. The ranges are wide because inheritance is random: you may share more or less DNA with a given relative than the average.

Relationship	Typical cM Range	Notes
Parent / Child	3,300-3,900	Nearly identical across families
Full Sibling	2,300-3,900	Wide range due to random inheritance
Half-Sibling	1,160-2,650
Grandparent / Grandchild	1,150-2,650
First Cousin	550-1,225	Average ~850 cM
First Cousin Once Removed	215-650
Second Cousin	41-592	Average ~230 cM
Third Cousin	0-173	Average ~74 cM
Fourth Cousin	0-139	May not appear at all

Important for Puerto Rican researchers: Because of endogamy (intermarriage within a relatively contained island population over generations), your cM totals with distant matches are often higher than these ranges suggest. A match showing 300 cM may be listed as a “2nd cousin” by AncestryDNA but could actually be a 4th or 5th cousin connected through multiple lines. A dedicated guide on this topic is coming soon: Puerto Rican DNA and Endogamy: Why Your Matches Look Closer Than They Are.

Step 3: Read Your Closest Matches First

Sort by closest match and work down. Start with matches sharing more than 200 cM, where the relationships are more predictable.

For each close match, check:

Do they have a family tree attached? A tree lets you see their surnames, birthplaces, and family lines. Even a short tree is useful.
Do you recognize any surnames? Puerto Rican genealogy concentrates around a relatively small number of family surnames per municipality. A shared surname is worth noting.
Does their “predicted relationship” make sense? AncestryDNA’s predicted relationships are a starting estimate. Check the actual cM amount and compare it to the table above.

If a close match has no tree and no information visible, you can still send them a message through AncestryDNA. Keep it brief and specific: who you are researching, which municipality, and which surnames you share. Many people respond, especially if they recognize the family.

Step 4: Use Shared Matches to Group Family Lines

Once you have identified a few confirmed relatives in your match list, the Shared Matches feature becomes your most powerful tool.

Here is how to use it:

Click on a match you have already identified (for example, a known cousin on your mother’s side).
On that match’s profile page, select Shared Matches.
AncestryDNA will show you every other match that you and this person share in common.

People who appear as shared matches with a known maternal-line relative are very likely also on your maternal line. People who do not appear are more likely paternal-line relatives. By repeating this process with confirmed relatives on different family lines, you can begin to sort your match list into family groups.

This sorting process is the foundation of more advanced work called clustering, which groups all your matches visually by shared family network. The clustering guide will be available as part of the upcoming DNA course on this site.

Step 5: Attach a Family Tree

A family tree is the bridge between your DNA matches and your documentary research.

When you attach even a small tree to your AncestryDNA profile, your matches can see your surnames and locations. This helps them recognize a possible connection, which makes them more likely to respond to messages and more likely to share what they know. It also lets AncestryDNA generate TreeMatch hints, which flag matches who appear to share a common ancestor in both of your trees.

You do not need a complete tree. A tree with three to four generations on each of your four grandparent lines is enough to make you visible. Include:

Full names (with maiden names for women)
Birth years and birthplaces (municipality, Puerto Rico)
Parents’ names where known

If you are just beginning, read Getting Started with Puerto Rican Genealogy for guidance on how to build your first tree from home records and family interviews.

When DNA Confirms vs. Conflicts with Records

DNA and documentary records work together. Neither is sufficient alone.

DNA confirms records when a close match shares a documented common ancestor with you and the cM total is consistent with the relationship the records show. This is the strongest situation: two independent lines of evidence pointing to the same conclusion.

DNA raises questions when a close match shows a much higher or lower cM total than expected for the documented relationship. Before drawing conclusions, consider:

Could the cM difference be explained by endogamy (multiple connecting lines)?
Is the documentary record itself reliable? Is it an original source or a later transcription?
Is the match’s tree accurate, or could it contain an error?

DNA does not prove identity. A cM total consistent with “1st cousin” does not confirm that two specific people are first cousins: it tells you that the amount of shared DNA falls within a range consistent with that relationship. The specific relationship still requires documentary evidence.

This is a core principle of the Genealogical Proof Standard: DNA evidence and documentary evidence must corroborate each other. DNA alone is not proof.

When Things Do Not Add Up

If your match list seems full of unexpectedly close matches you cannot identify, or if cM totals feel higher than they should be for the relationships you know, you are likely seeing the effects of endogamy.

For Puerto Rican researchers, this is normal. It is not a problem with your results. It is a feature of researching an island population where families intermarried across generations.

The practical response is to:

Work sideways (collateral lines: aunts, uncles, cousins) rather than only upward in your tree
Look for surname and municipality patterns across your match list, not just individual relationships
Use Shared Matches to group family networks, then research the network rather than individual relationships

A detailed explanation of how endogamy affects Puerto Rican DNA research will be in the upcoming guide: Puerto Rican DNA and Endogamy: Why Your Matches Look Closer Than They Are (coming soon).

What Comes Next: Clustering

The five steps in this guide set up your foundation: you understand what your matches represent, you have used Shared Matches to begin grouping family lines, and you have a tree attached to make yourself visible.

The next level of DNA analysis is clustering: systematically grouping all your matches by shared family network, so that each cluster maps approximately to a single ancestral couple in your tree.

The most widely used clustering technique is the Leeds Method, developed by genealogist Dana Leeds. The basic process:

Take your top matches above a certain cM threshold (typically 90 cM or higher).
Pick the first unassigned match and find all its Shared Matches.
Assign that group a color. Every match in that group gets the same color.
Move to the next unassigned match and repeat.

The result is four color groups, each corresponding roughly to one of your four grandparent lines. Matches you cannot assign to a group are set aside for later.

For Puerto Rican researchers, the Leeds Method requires adjustments because endogamy inflates cM totals and causes matches to appear in multiple groups. The standard approach is to raise the starting threshold to 90-400 cM to filter out background Puerto Rican relatedness, then work through the groups more cautiously. An endogamy-adjusted walkthrough of the Leeds Method for Puerto Rican research will be covered in the upcoming DNA Fundamentals course on this site.

Learn More

Resource	What It Offers
The Family Tree Guide to DNA Testing and Genetic Genealogy by Blaine T. Bettinger	Clearest beginner-level book on genetic genealogy. Covers the AncestryDNA workflow in detail, including shared matches and tree-building.
Genetic Genealogy in Practice by Blaine T. Bettinger and Angie Bush	Workbook format: exercises for applying DNA analysis, including clustering and endogamy.
ISOGG Wiki	Reference encyclopedia for genetic genealogy terms. Use it when you encounter unfamiliar terminology.
DNA Painter	Free tool for visualizing shared DNA segments and calculating relationship probabilities from cM amounts.

Notice: Found a broken link or error? Report it here.