Genetic Genealogy: How to Research Your Family History with DNA

Genealogy is the study of family history and lineage. It helps trace how people are connected across generations by combining documents, family testimony and, increasingly, DNA analysis. In England, traditional archive work still matters greatly, and a practical starting point remains the The National Archives family history guidance, especially when you need to structure research around historical records and census material.

The Two Main Types of Genealogy

Genealogy can be approached in two different ways, depending on the direction of the research.

Ascending genealogy

Ascending genealogy begins with one person and works backwards to identify their ancestors. Starting from the individual at the base of the tree, the research gradually moves up through parents, grandparents and earlier generations.

Descending genealogy

Descending genealogy starts with one person, or one couple, and aims to identify all their descendants. This method is especially useful when the goal is to understand how different branches of a family connect over time or to clarify kinship between living relatives.

Traditional Genealogy

Traditional genealogy is based on archives, records and family documents that help reconstruct a person’s ancestry or descent. Its purpose is to establish, confirm or challenge family links across several generations.

The documents used can include:

• birth certificates

• marriage certificates

• death certificates and notices

• wills

• property records

• family record books

• judicial or notarial archives

• parish or religious registers

• private letters, family papers and oral testimony

In practice, the best results usually come from cross-checking official records with family stories rather than relying on one source alone. That method helps reduce errors, identify missing branches and create a stronger framework before using DNA evidence.

Today, genealogists also use specialised platforms that make archival work easier. Some services help users build family trees, while others combine historical records with matching tools to connect people working on related lines of research.

Genetic Genealogy

Genetic genealogy is the branch of genealogy based on DNA analysis. A laboratory analyses part of your DNA and compares it with a database of other tested individuals. The objective is not simply to produce a genetic profile, but to identify patterns that may help you understand ancestry and biological relationships.

This type of analysis generally produces two main categories of results:

• an estimate of your geographical origins

• a list of genetic matches

Genetic matches are people tested in the same database who share identifiable DNA segments with you. The amount of shared DNA can help estimate how close or distant the relationship may be.

What DNA Testing Can Add to Genealogy

A genealogy DNA test does not replace documentary research. It complements it. Used properly, it can confirm a branch, reopen a dead end, or reveal a line that written records never made clear.

1. Estimating geographical origins

An ancestry DNA test can provide an estimate of the populations and regions most strongly associated with your DNA. These results are not exact proof of nationality or ethnicity, but they can give useful clues about where parts of your ancestry may be rooted.

That is particularly helpful when you are working with incomplete records, migration histories or family stories that are difficult to verify. For readers who want a broader UK-focused overview, this guide to an ancestry DNA test in the UK is a useful complement.

2. Building or checking your family tree

One of the main strengths of genetic genealogy is the ability to compare your documentary tree with your genetic one. A DNA test may confirm that a branch appears coherent, but it can also reveal that a supposed line does not fit the genetic evidence.

It can also help you connect with third, fourth or fifth cousins, then use their family trees to identify a shared ancestral line. In other words, DNA can help validate your work, but also extend it.

3. Finding unknown relatives

Genetic genealogy is particularly useful when there is a major gap in the family story, for example after adoption, donor conception, an unknown father, or an unresolved family rumour. In those situations, DNA matches may provide the first reliable lead toward a biological branch that was previously undocumented.

When the goal is to identify a close unknown relative, it is often helpful to combine genetic genealogy with a more targeted process such as this guide on using a DNA test to find an unknown parent.

Why Database Choice Matters

A key limitation of genetic genealogy is simple: databases are private. Your matches depend partly on where you test. A strong result in one database does not guarantee the same result elsewhere.

For that reason, people who are serious about genealogical research often use more than one platform, especially when they are trying to identify an unknown branch or maximise the number of cousin matches available for analysis. The broader the database coverage, the better the chance of finding a useful lead.

Which DNA Test Should You Choose?

There is no universal best test. The right option depends on what you are trying to discover.

You want more detailed ancestry and regional origin estimates

23andMe is often chosen first when the priority is ancestry breakdown and geographical detail. Its ancestry service highlights detailed locations and DNA relatives, and its raw genetic data can also be accessed from the account. That makes it a strong starting point for people who want a broad ancestry overview before expanding into deeper genealogical research.

You want to expand cousin matching and build a broader tree

If your goal is to identify relatives, especially across North America and internationally, Ancestry is often the strongest starting point because of the scale of its DNA network. Ancestry states that it has more than 27 million people in its growing DNA network, which explains why it is frequently used for large-scale cousin matching and tree-building.

You are researching European family lines

MyHeritage remains useful for European genealogy because it combines DNA services, tree-building tools and a very large collection of historical records. That said, its current policy has changed: third-party autosomal DNA uploads are no longer supported, so users now need a MyHeritage kit to receive DNA matches and ethnicity reports on the platform.

You need a paternal or maternal lineage test

FamilyTreeDNA is the most relevant choice when the research specifically concerns a direct paternal or maternal line. It offers dedicated Y-DNA and mtDNA testing, which remains a major advantage for surname studies, deep paternal lineage work, maternal-line tracing, and some unknown-parent investigations. For readers focused on a direct male line, a dedicated Y-chromosome DNA test can be especially relevant.

How to Transfer DNA Results Between Platforms

Genealogical research often requires comparing, storing and cross-referencing results from different services. That is why raw DNA data matters.

In practical terms, many users download their raw data from the provider where they first tested, then upload a copy to another platform when that second platform accepts transfers. 23andMe provides access to raw genetic data from the user account. MyHeritage also allows users to download their raw DNA file from their kit management area. Ancestry’s privacy settings also include the ability to download raw DNA data.

However, not every company handles transfers in the same way. FamilyTreeDNA currently accepts autosomal transfers from AncestryDNA, 23andMe and MyHeritage. By contrast, MyHeritage no longer accepts autosomal uploads from other testing services. That means the old strategy of freely moving results into MyHeritage is no longer current.

For serious research, this has a direct consequence: transferring data can still broaden your match pool, but only on platforms that actively support uploads. You should therefore check current transfer rules before ordering a kit or planning a multi-database strategy.

A Practical Rule Before Ordering Any Test

Before choosing a company, check four points:

• the type of test offered

• the size and relevance of the database

• whether raw data can be downloaded

• whether the platform accepts transfers from other services

That simple check often matters more than marketing claims, because in genealogy the quality of the match environment is usually more important than the packaging of the kit itself.

	MyHeritage	Ancestry	23andMe	FamilytreeDNA
Precision of geographical origins	+++	++	​+++	+
Family tree	YES	YES	NO	YES
Import your data	YES	YES	NO	NO
mtDNA	NO	NO	NO	YES
Y-DNA	NO	NO	NO	YES
​Subscription	YES	NO	NO	NO
Test price	​+	++	+++	+

How to transfer the results?

Genealogical research often leads to having to relate, but also record, exchange, and merge the data from the results of genetic tests. To deepen your analyses and increase the chances of matches, the laboratories allow you to transfer the raw information from one database to another.

In this transfer policy, most laboratories accept that the raw information (raw data) can be downloaded by the person concerned. But not all of them give you the possibility to add information from a third-party laboratory.

Today, the MyHeritage and FamilytreeDNA laboratories are the most flexible and allow the addition of genetic information from any other competing laboratory.

	Transfer from :
To :	MyHeritage	Ancestry	23andMe	FamilytreeDNA
MyHeritage		YES	YES	YES
Ancestry	NO		NO	NO
23andMe	NO	NO		NO
FamilytreeDNA	YES	YES	YES

Conclusion

Genetic genealogy is most effective when it is used alongside traditional genealogy, not instead of it. Archives, certificates and family records help establish the structure of a family tree. DNA testing helps confirm, refine or challenge that structure by revealing ancestry estimates and genetic matches.

Used together, these two approaches can help you understand your origins more clearly, build a more reliable family tree, and sometimes identify relatives who would never have appeared in written records alone. The key is to choose the right test for the right objective, and to work methodically from evidence rather than assumptions.