3D skull analysis debunks what we know about Anglo-Saxons
For historic Britons, ancestry may be more learned than genetic.
Long before it became the top exporter of brooding BBC actors or steamed puddings, the United Kingdom was simply a cold, rocky island off the coast of Europe. It wasn’t until the arrival of Germanic-speaking peoples from Europe between the 5th and 7th centuries that the British isles — and slowly, the English language itself — became what we know today.
Or at least that’s what the Germanic records want us to believe. But new archaeological analysis of skulls exhumed on the island point toward a much more “mixed and malleable” origin of the Anglo-Saxons.
“Anglo-Saxon identity was based on cultural practices and language, not genetics,” Kimberly Plomp, the study’s first author and professor at Simon Fraser University, tells Inverse. “It appears that England in the Anglo-Saxon period was surprisingly similar to modern-day England.”
What’s new — Previous knowledge of early Anglo-Saxon origins have largely relied on either historic texts — written by Germanic invaders to the islands — or genetic and isotope testing of recovered remains. The authors write that while both methods have their own validity, they’re also variable and not always in agreement with each other.
The Germanic records, for example, claim that the indigenous peoples of the islands were overrun in one large invasion. However, isotopic analysis of Anglo-Saxon skeletons suggests that many were instead local to the island.
In their new work, published Wednesday in the journal PLOS ONE, a trio of researchers from the U.K., British Columbia, and Australia offer a new type of analysis in the “geometric morphometrics” — or, a 3D analysis of skulls.
“These shape differences are so subtle that they often can't be seen with the naked eye,” explains Plomp. “[So] we are using very sophisticated statistical methods to compare the shape of the cranial bases.
“It is based on the same idea that I look more similar to my sisters than I do to my cousins, but I look more similar to my cousins than I do to my neighbors,” Plomp adds. “It's all about genetics and being related to people within your population or genetic pool.”
Why it matters — Just because history is behind us doesn’t necessarily mean it's written in stone. New discoveries like this can help historians and the public alike reimagine these ancient peoples and find a new understanding of what it means to be Anglo-Saxon — both in the past and today.
As science and history have shown, it has less to do with genetics and ethnicity than we’ve been lead to believe.
“Basically, you can think of cranial base shape as a proxy for DNA.”
Here’s the background — Before they became notorious colonizers in their own right, the people of the modern-day U.K. underwent their own thousand-year-long invasion between 55 BC and 1066 AD at the hands of Roman forces, Vikings, and later Normans.
In their work, the researchers looked at remains that fell between these dates, including:
- Middle Anglo-Saxon cemeteries (410-899 CE)
- Pre-Medieval sites in England (800 BCE-410 CE)
- Iron Age sites in Denmark (800 BCE-399 CE), with whom the Anglo-Saxons had genetic similarities
What they did — The team analyzed 236 human skulls collected from these cemeteries and used a rotating table and eight-megapixel camera to snap 150 images of each skull. These images were then stitched together digitally to create a 3D model of the skulls that the team could more easily manipulate.
This hands-free nature of the 3D model is something Plomp says is essential in delicate work like this. Plomp says the method “does not require us to destroy the bone in any way.”
“By using these methods, we were actually able to create high-quality digital scans of the skulls that can be used for other research later, and thus potentially reduce the number of people that would need to physically handle the fragile bones as well as make them easily shareable,” she says.
From these models, Plomp says the team specifically studied the base of the skulls which previous research has demonstrated “retains a genetic signal” to draw connections between different populations.
If using skull shape to divine characteristics about a person sets off alarm bells in the back of your mind, you may be thinking of an old (and racist in origin) pseudoscience from the 19th century called phrenology that claimed a person’s intelligence could be judge based on the shape of their skull. Of course, in this pseudoscience, the skulls of white men had the most desirable shape.
Plomp, however, says that their 3D model analysis is “absolutely not” comparable to the methods of phrenology.
“Phrenology was a pseudoscience that mistakenly claimed that assessments of cranial shape could say something about the mental abilities of individuals and populations,” she says. “Our study's goal was very different [...] We used cranial base shape to infer the ancestry of individuals in a similar way to DNA is used to infer ancestry by companies like 23andMe.”
“Basically, you can think of cranial base shape as a proxy for DNA,” she continues. “At the moment, it's a lot cheaper to photograph crania and run the type of analyses we ran than it is to recover DNA from ancient skeletons. So, the method we used can be employed on larger samples, which is important for addressing scientific questions.”
What they discovered — Through this analysis, the team found that the early Anglo-Saxon skeletons were of 25-33 percent local ancestry (e.g. Celts) while the middle Anglo-Saxon skeletons were of a greater 50-70 percent local ancestry.
The researchers say more work needs to be done to understand this change, but Plomp says it suggests that Anglo-Saxon identity was not simply based on genetics but instead more likely based on shared cultural practices. This is the same story researchers discovered last year when it comes to the DNA of Vikings.
“England is a country with an unusually high level of diversity in relation to ancestry, as anybody watching the current Euros soccer competition will readily appreciate,” says Plomp. “But of course the vast majority of people living in the country speak the same language and share a large number of cultural values and practices, including being pessimistic about the chances of the England soccer team winning the Euros.”
Abstract: The settlement of Great Britain by Germanic-speaking people from continental northwest Europe in the Early Medieval period (early 5th to mid 11th centuries CE) has long been recognised as an important event, but uncertainty remains about the number of settlers and the nature of their relationship with the preexisting inhabitants of the island. In the study reported here, we sought to shed light on these issues by using 3D shape analysis techniques to compare the cranial bases of Anglo-Saxon skeletons to those of skeletons from Great Britain that pre-date the Early Medieval period and skeletons from Denmark that date to the Iron Age. Analyses that focused on Early Anglo-Saxon skeletons indicated that between two thirds and three-quarters of Anglo-Saxon individuals were of continental northwest Europe ancestry, while between a quarter and one-third were of local ancestry. In contrast, analyses that focused on Middle Anglo-Saxon skeletons suggested that 50–70% were of local ancestry, while 30–50% were of continental northwest Europe ancestry. Our study suggests, therefore, that ancestry in Early Medieval Britain was similar to what it is today—mixed and mutable.