While going through my many unopened emails, I came across one from Science Daily. I had subscribed to the newsletter intending to read it daily to expand my knowledge about developments in the world of science, but I hadn’t followed through. Determined to change my monotonous routine, I decided to read it. One article caught my attention: “A Genetic Tree as a Movie: Moving Beyond the Still Portrait of Ancestry.” 

I thought to myself, “A genetic tree movie? That must be fascinating to create!” However, I soon realized that my idea of a movie was very different from what the article was discussing. 

The article introduced a new statistical method called Gaia (Geographic Ancestry Inference Algorithm), which provides a continuous view of ancestry. Unlike traditional DNA tests that offer only a snapshot of a person’s genetic ties to a specific region at a fixed point in time, Gaia traces how ancestors moved across different regions over centuries.

Imagine you take a DNA test, and it reveals that you’re 50% Irish and 50% Italian. At first glance, it might seem like your family roots are pretty straightforward, with origins solely in those two places. But Gaia digs a little deeper.

Think about it: your Irish ancestors didn’t always call Ireland home. A long time ago, some of them might have sailed from Scandinavia during the Viking migrations. 

And what about your Italian roots? Chances are they stretch farther than just the Italian peninsula. Your ancestors might have connections to North Africa or the Middle East—after all, ancient trade routes and conquests brought diverse people together in Italy, blending cultures and traditions.

Over the centuries, your ancestors likely moved around, mingling with different groups and adapting to new environments. Instead of a simple snapshot, the Gaia method unveils a rich tapestry of your family’s journey through time and space. It’s an incredible reminder that our identities are shaped by the many paths that brought us to where we are now.[1]

Now that we understand how Gaia enhances our knowledge of ancestry, let’s take a step back and explore the fundamental concepts that shape our understanding of family history.

In general, ancestors mean a connection to the people or things in the past. But in genetics, ancestry means how you are the biological descendants of your ancestors and how their DNA has been passed on to you.

Ancestry can be divided into two main types: genealogical and genetic. 

Genealogical ancestry refers to your entire family tree, including all biological ancestors based on family records. For example, if you trace back ten generations, you might find you have 1,024 ancestors!

On the other hand, genetic ancestry focuses on the DNA you inherit. While you may have ancestors from various regions—like a great-grandparent from China and another from Scandinavia—you don’t inherit genes from all of them. You might carry genetic traits from your Scandinavian ancestor but not from the others, meaning they are part of your family history, even if they’re not in your DNA.[2]

So how is it done? By comparing your unique DNA variants with those from diverse populations worldwide, scientists can estimate the regions where your ancestors originated.

There are three primary types of testing:

1. Mitochondrial DNA (mtDNA): This is passed from mother to child and reveals your maternal lineage.

2. Y Chromosome DNA: Inherited from father to son, this type highlights your paternal ancestry.

3. Autosomal DNA (SNVs/SNPs): This is inherited from both parents and provides a broad perspective on your ancestry.

Autosomal tests examine hundreds of thousands of DNA variants, mapping their origins to specific geographic regions. [3]

Exploring your ancestry can be an emotional rollercoaster. DNA tests may uncover unexpected results—hidden family secrets, lost connections, or even a cultural identity different from what you’ve always believed. This can be exciting for some, but unsettling for others, making the journey anything but simple.

According to a study by Rubanovich, Caryn Kseniya et al. most participants found ancestry test results impactful but not distressing, with nearly half experiencing shifts in their view of cultural roots and 25% reporting changes in cultural identity. White participants were less likely to change their perspectives compared to racial and ethnic minorities, who often skipped results due to stronger ancestral ties. Higher education correlated with greater engagement. While curiosity and genealogical research motivated testing, some felt negatively when results contradicted family narratives. Over 80% planned to share results with family, but conflicting outcomes made this difficult. Additionally, more than 12% intended to discuss results with healthcare providers, raising concerns about the interpretation of ancestry and health testing.[4]

These emotional and cultural shifts highlight that ancestry is more than just genetics—it shapes our sense of self, family, and belonging in ways we may not have anticipated.

If someone from a hundred years ago could see how we trace our ancestry today, it would be mind-blowing. Science continues to reshape our understanding of where we come from, proving that ancestry isn’t just a set of fixed roots—it’s an evolving story, one that technology is helping us piece together like never before.

Sources:

1. University of Michigan. “A genetic tree as a movie: Moving beyond the still portrait of ancestry.” ScienceDaily. ScienceDaily, 27 March 2025. www.sciencedaily.com/releases/2025/03/250327164606.htm.
2. Mathieson, Iain, and Aylwyn Scally. “What is ancestry?.” PLoS genetics vol. 16,3 e1008624. 9 Mar. 2020, doi:10.1371/journal.pgen.1008624
3. Jorde, Lynn B, and Michael J Bamshad. “Genetic Ancestry Testing: What Is It and Why Is It Important?.” JAMA vol. 323,11 (2020): 1089-1090. doi:10.1001/jama.2020.0517
4. Rubanovich, Caryn Kseniya et al. “Impacts of personal DNA ancestry testing.” Journal of community genetics vol. 12,1 (2021): 37-52. doi:10.1007/s12687-020-00481-5